Add resumable downloads, download paths, queue controls and history

.env.example

@@ -14,4 +14,5 @@ DOWNLOAD_HOST_DIR=./data/downloads
 
 MIN_FREE_GB=10
 MAX_CONCURRENT_DOWNLOADS=2
+CONNECTIONS_PER_DOWNLOAD=4
 ALLOWED_PORTS=80,443

README.md

@@ -18,11 +18,12 @@ Self-hosted direct download client that fetches files onto the server, extracts
 | `internal/libraries` | Discovers and validates first level library folders |
 | `internal/auth` | Sessions, credential check, login rate limiting |
 | `internal/guard` | URL validation and SSRF-safe HTTP client |
-| `internal/fetch` | Streaming download with progress, size and stall limits |
+| `internal/fetch` | Resumable multi-connection downloads with progress, size and stall limits |
+| `internal/history` | Move history saved to `.history.json` |
 | `internal/extract` | Zip and tar extraction with Zip Slip and bomb protection |
 | `internal/files` | Safe path resolution, file tree, cross-device moves |
 | `internal/diskspace` | Free space checks |
-| `internal/jobs` | Download job lifecycle and workflows |
+| `internal/jobs` | Download job lifecycle, pause and resume, state saved to `.job.json` per download |
 | `internal/server` | HTTP routes, middleware, handlers |
 | `web/static` | Single page frontend |
 | `deploy/nginx` | Reverse proxy example |

internal/config/config.go

@@ -38,6 +38,7 @@ func Load() (Settings, error) {
 		DownloadDir:       filepath.Clean(reader.text("DOWNLOAD_DIR", "/data/downloads")),
 		Defaults: preferences.Preferences{
 			MaxConcurrentDownloads: reader.integer("MAX_CONCURRENT_DOWNLOADS", 2),
+			ConnectionsPerDownload: reader.integer("CONNECTIONS_PER_DOWNLOAD", 4),
 			MinFreeGB:              reader.integer("MIN_FREE_GB", 10),
 			AllowedPorts:           reader.ports("ALLOWED_PORTS", "80,443"),
 			AutoExtract:            true,

internal/fetch/copy.go

@@ -0,0 +1,55 @@
+package fetch
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"sync/atomic"
+	"time"
+)
+
+const (
+	bufferSize   = 1 << 20
+	stallTimeout = 2 * time.Minute
+)
+
+func copyBody(destination io.Writer, body io.ReadCloser, remaining int64, record func(int64) error) error {
+	var stalled atomic.Bool
+	stallTimer := time.AfterFunc(stallTimeout, func() {
+		stalled.Store(true)
+		body.Close()
+	})
+	defer stallTimer.Stop()
+
+	buffer := make([]byte, bufferSize)
+	for remaining != 0 {
+		readSize := len(buffer)
+		if remaining > 0 && remaining < int64(readSize) {
+			readSize = int(remaining)
+		}
+
+		count, readErr := body.Read(buffer[:readSize])
+		if count > 0 {
+			stallTimer.Reset(stallTimeout)
+			if _, err := destination.Write(buffer[:count]); err != nil {
+				return err
+			}
+			if err := record(int64(count)); err != nil {
+				return err
+			}
+			if remaining > 0 {
+				remaining -= int64(count)
+			}
+		}
+		if errors.Is(readErr, io.EOF) {
+			return nil
+		}
+		if readErr != nil {
+			if stalled.Load() {
+				return ErrStalled
+			}
+			return fmt.Errorf("%w: %w", errConnectionFailed, readErr)
+		}
+	}
+	return nil
+}

internal/fetch/downloader.go

@@ -3,25 +3,15 @@ package fetch
 import (
 	"context"
 	"errors"
-	"fmt"
-	"io"
 	"net/http"
 	"os"
 	"path/filepath"
-	"time"
 
 	"ddc/internal/diskspace"
 	"ddc/internal/files"
 	"ddc/internal/guard"
 )
 
-const (
-	userAgent          = "ddc/1.0"
-	bufferSize         = 1 << 20
-	stallTimeout       = 2 * time.Minute
-	spaceCheckInterval = int64(256) << 20
-)
-
 var (
 	ErrIncomplete = errors.New("download ended before the full file was received")
 	ErrStalled    = errors.New("download stalled, no data received for too long")
@@ -29,8 +19,21 @@ var (
 
 type Progress interface {
 	SetTotal(total int64)
+	SetDone(done int64)
 	Add(delta int64)
 	SetFileName(name string)
+	SetNotice(text string)
+}
+
+type Request struct {
+	URL           string
+	Directory     string
+	FileName      string
+	ReservedBytes int64
+	Connections   int
+	State         *State
+	Progress      Progress
+	Checkpoint    func(State)
 }
 
 type Downloader struct {
@@ -42,111 +45,99 @@ func NewDownloader(policy *guard.Policy) *Downloader {
 	return &Downloader{policy: policy, client: policy.NewHTTPClient()}
 }
 
-func (downloader *Downloader) Download(ctx context.Context, rawURL, directory string, reservedBytes int64, progress Progress) (string, error) {
-	target, err := downloader.policy.ValidateURL(rawURL)
+func (downloader *Downloader) Download(ctx context.Context, request Request) (string, error) {
+	target, err := downloader.policy.ValidateURL(request.URL)
 	if err != nil {
 		return "", err
 	}
 
-	ctx, cancel := context.WithCancelCause(ctx)
-	defer cancel(nil)
-
-	response, err := downloader.open(ctx, target.String())
+	source := &remoteFile{url: target.String()}
+	partPath := filepath.Join(request.Directory, files.PartFileName)
+	state, probe, err := downloader.prepare(ctx, source, request, partPath)
 	if err != nil {
 		return "", err
 	}
-	defer response.Body.Close()
 
-	fileName := FileNameFromResponse(response)
-	progress.SetFileName(fileName)
-	if err := diskspace.EnsureFree(directory, max(response.ContentLength, 0), reservedBytes); err != nil {
+	progress := request.Progress
+	progress.SetFileName(state.FileName)
+	progress.SetTotal(state.TotalBytes)
+	progress.SetDone(state.DoneBytes())
+	remainingBytes := max(state.TotalBytes-state.DoneBytes(), 0)
+	if err := diskspace.EnsureFree(request.Directory, remainingBytes, request.ReservedBytes); err != nil {
+		closeBody(probe)
 		return "", err
 	}
-	progress.SetTotal(max(response.ContentLength, 0))
 
-	partPath := filepath.Join(directory, files.PartFileName)
-	written, err := writePart(cancel, partPath, response.Body, progress, directory, reservedBytes)
+	file, err := openPartFile(partPath, probe != nil)
 	if err != nil {
-		os.Remove(partPath)
-		if errors.Is(context.Cause(ctx), ErrStalled) {
-			return "", ErrStalled
-		}
+		closeBody(probe)
 		return "", err
 	}
-	if response.ContentLength > 0 && written != response.ContentLength {
-		os.Remove(partPath)
-		return "", ErrIncomplete
+	runErr := newSession(downloader, source, file, request, state).run(ctx, probe)
+	closeErr := file.Close()
+	if runErr != nil {
+		return "", runErr
+	}
+	if closeErr != nil {
+		return "", closeErr
 	}
 
-	finalPath := files.UniquePath(filepath.Join(directory, fileName))
+	finalPath := files.UniquePath(filepath.Join(request.Directory, state.FileName))
 	if err := os.Rename(partPath, finalPath); err != nil {
-		os.Remove(partPath)
 		return "", err
 	}
 	return finalPath, nil
 }
 
-func (downloader *Downloader) open(ctx context.Context, target string) (*http.Response, error) {
-	request, err := http.NewRequestWithContext(ctx, http.MethodGet, target, nil)
-	if err != nil {
-		return nil, err
+func (downloader *Downloader) prepare(ctx context.Context, source *remoteFile, request Request, partPath string) (State, *http.Response, error) {
+	if request.State != nil && request.State.valid() && fileExists(partPath) {
+		state := *request.State
+		source.validator = state.Validator
+		source.totalBytes = state.TotalBytes
+		return state, nil, nil
 	}
-	request.Header.Set("User-Agent", userAgent)
-	request.Header.Set("Accept-Encoding", "identity")
 
-	response, err := downloader.client.Do(request)
+	probe, err := downloader.open(ctx, source, 0, 0)
 	if err != nil {
-		return nil, err
+		return State{}, nil, err
 	}
-	if response.StatusCode != http.StatusOK {
+	source.describe(probe)
+
+	connections := 1
+	if probe.Header.Get("Accept-Ranges") == "bytes" {
+		connections = min(max(request.Connections, 1), MaxConnections)
+	}
+	state := State{
+		FileName:   chooseFileName(request.FileName, probe),
+		Validator:  source.validator,
+		TotalBytes: source.totalBytes,
+		Segments:   planSegments(source.totalBytes, connections),
+	}
+	return state, probe, nil
+}
+
+func chooseFileName(requested string, response *http.Response) string {
+	if name := SanitizeFileName(requested); name != "" {
+		return name
+	}
+	return FileNameFromResponse(response)
+}
+
+func openPartFile(partPath string, fresh bool) (*os.File, error) {
+	flags := os.O_WRONLY | os.O_CREATE
+	if fresh {
+		flags |= os.O_TRUNC
+	}
+	return os.OpenFile(partPath, flags, 0o644)
+}
+
+func fileExists(path string) bool {
+	info, err := os.Stat(path)
+	return err == nil && info.Mode().IsRegular()
+}
+
+func closeBody(response *http.Response) {
+	if response != nil {
 		response.Body.Close()
-		return nil, fmt.Errorf("server responded with %s", response.Status)
-	}
-	return response, nil
-}
-
-func writePart(cancel context.CancelCauseFunc, partPath string, body io.Reader, progress Progress, directory string, reservedBytes int64) (int64, error) {
-	file, err := os.OpenFile(partPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0o644)
-	if err != nil {
-		return 0, err
-	}
-	written, copyErr := copyBody(cancel, file, body, progress, directory, reservedBytes)
-	closeErr := file.Close()
-	if copyErr != nil {
-		return written, copyErr
-	}
-	return written, closeErr
-}
-
-func copyBody(cancel context.CancelCauseFunc, destination io.Writer, body io.Reader, progress Progress, directory string, reservedBytes int64) (int64, error) {
-	stallTimer := time.AfterFunc(stallTimeout, func() { cancel(ErrStalled) })
-	defer stallTimer.Stop()
-
-	buffer := make([]byte, bufferSize)
-	var written, sinceSpaceCheck int64
-	for {
-		count, readErr := body.Read(buffer)
-		if count > 0 {
-			stallTimer.Reset(stallTimeout)
-			if _, err := destination.Write(buffer[:count]); err != nil {
-				return written, err
-			}
-			written += int64(count)
-			sinceSpaceCheck += int64(count)
-			progress.Add(int64(count))
-
-			if sinceSpaceCheck >= spaceCheckInterval {
-				sinceSpaceCheck = 0
-				if err := diskspace.EnsureFree(directory, 0, reservedBytes); err != nil {
-					return written, err
-				}
-			}
-		}
-		if errors.Is(readErr, io.EOF) {
-			return written, nil
-		}
-		if readErr != nil {
-			return written, readErr
-		}
 	}
 }

internal/fetch/request.go

@@ -0,0 +1,141 @@
+package fetch
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"ddc/internal/guard"
+)
+
+const userAgent = "ddc/1.0"
+
+var (
+	ErrResumeUnsupported = errors.New("connection was lost and the server does not support resuming")
+	ErrSourceChanged     = errors.New("file changed on the server while downloading")
+	errConnectionFailed  = errors.New("connection to the server failed")
+	errServerUnavailable = errors.New("server is temporarily unavailable")
+)
+
+type remoteFile struct {
+	url        string
+	validator  string
+	totalBytes int64
+}
+
+func (source *remoteFile) describe(response *http.Response) {
+	source.totalBytes = max(response.ContentLength, 0)
+	source.validator = validatorOf(response.Header)
+}
+
+func validatorOf(header http.Header) string {
+	if entityTag := header.Get("ETag"); entityTag != "" && !strings.HasPrefix(entityTag, "W/") {
+		return entityTag
+	}
+	return header.Get("Last-Modified")
+}
+
+type cancelingBody struct {
+	io.ReadCloser
+	cancel context.CancelFunc
+}
+
+func (body *cancelingBody) Close() error {
+	body.cancel()
+	return body.ReadCloser.Close()
+}
+
+func (downloader *Downloader) open(ctx context.Context, source *remoteFile, position, end int64) (*http.Response, error) {
+	requestContext, cancelRequest := context.WithCancel(ctx)
+	response, err := downloader.send(requestContext, source, position, end)
+	if err != nil {
+		cancelRequest()
+		return nil, err
+	}
+	response.Body = &cancelingBody{ReadCloser: response.Body, cancel: cancelRequest}
+	return response, nil
+}
+
+func (downloader *Downloader) send(ctx context.Context, source *remoteFile, position, end int64) (*http.Response, error) {
+	request, err := http.NewRequestWithContext(ctx, http.MethodGet, source.url, nil)
+	if err != nil {
+		return nil, err
+	}
+	request.Header.Set("User-Agent", userAgent)
+	request.Header.Set("Accept-Encoding", "identity")
+
+	ranged := position > 0 || (end > 0 && end < source.totalBytes)
+	if ranged {
+		request.Header.Set("Range", rangeHeader(position, end))
+		if source.validator != "" {
+			request.Header.Set("If-Range", source.validator)
+		}
+	}
+
+	response, err := downloader.client.Do(request)
+	if err != nil {
+		return nil, connectionError(err)
+	}
+	if err := checkResponse(response, source, position, ranged); err != nil {
+		response.Body.Close()
+		return nil, err
+	}
+	return response, nil
+}
+
+func rangeHeader(position, end int64) string {
+	if end > 0 {
+		return fmt.Sprintf("bytes=%d-%d", position, end-1)
+	}
+	return fmt.Sprintf("bytes=%d-", position)
+}
+
+func checkResponse(response *http.Response, source *remoteFile, position int64, ranged bool) error {
+	status := response.StatusCode
+	switch {
+	case !ranged && status == http.StatusOK:
+		if source.totalBytes > 0 && response.ContentLength != source.totalBytes {
+			return ErrSourceChanged
+		}
+		return nil
+	case ranged && status == http.StatusPartialContent:
+		return checkContentRange(response.Header.Get("Content-Range"), source.totalBytes, position)
+	case ranged && status == http.StatusOK:
+		if source.validator != "" && validatorOf(response.Header) != source.validator {
+			return ErrSourceChanged
+		}
+		return ErrResumeUnsupported
+	case status == http.StatusTooManyRequests || status >= http.StatusInternalServerError:
+		return fmt.Errorf("%w (%s)", errServerUnavailable, response.Status)
+	default:
+		return fmt.Errorf("server responded with %s", response.Status)
+	}
+}
+
+func checkContentRange(header string, totalBytes, offset int64) error {
+	rangeText, found := strings.CutPrefix(header, "bytes ")
+	if !found {
+		return ErrResumeUnsupported
+	}
+	span, totalText, found := strings.Cut(rangeText, "/")
+	startText, _, _ := strings.Cut(span, "-")
+	start, err := strconv.ParseInt(startText, 10, 64)
+	if !found || err != nil || start != offset {
+		return ErrResumeUnsupported
+	}
+	if totalBytes > 0 && totalText != "*" && totalText != strconv.FormatInt(totalBytes, 10) {
+		return ErrSourceChanged
+	}
+	return nil
+}
+
+func connectionError(err error) error {
+	if errors.Is(err, guard.ErrBlockedAddress) || errors.Is(err, guard.ErrBlockedPort) || errors.Is(err, guard.ErrTooManyRedirects) {
+		return err
+	}
+	return fmt.Errorf("%w: %w", errConnectionFailed, err)
+}

internal/fetch/session.go

@@ -0,0 +1,128 @@
+package fetch
+
+import (
+	"context"
+	"net/http"
+	"os"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"ddc/internal/diskspace"
+)
+
+const (
+	checkpointInterval = 10 * time.Second
+	spaceCheckInterval = int64(256) << 20
+)
+
+type session struct {
+	downloader      *Downloader
+	source          *remoteFile
+	file            *os.File
+	request         Request
+	state           State
+	segments        []*liveSegment
+	sinceSpaceCheck atomic.Int64
+}
+
+func newSession(downloader *Downloader, source *remoteFile, file *os.File, request Request, state State) *session {
+	segments := make([]*liveSegment, len(state.Segments))
+	for index, segment := range state.Segments {
+		segments[index] = newLiveSegment(segment)
+	}
+	return &session{
+		downloader: downloader,
+		source:     source,
+		file:       file,
+		request:    request,
+		state:      state,
+		segments:   segments,
+	}
+}
+
+func (session *session) run(ctx context.Context, probe *http.Response) error {
+	session.saveCheckpoint()
+	stopSaving := make(chan struct{})
+	savingStopped := make(chan struct{})
+	go session.saveCheckpoints(stopSaving, savingStopped)
+
+	err := session.runWorkers(ctx, probe)
+	close(stopSaving)
+	<-savingStopped
+	session.saveCheckpoint()
+	return err
+}
+
+func (session *session) runWorkers(ctx context.Context, probe *http.Response) error {
+	ctx, cancel := context.WithCancelCause(ctx)
+	defer cancel(nil)
+
+	var workers sync.WaitGroup
+	var firstFailure sync.Once
+	var failure error
+	for index, segment := range session.segments {
+		if segment.complete() {
+			continue
+		}
+		var initial *http.Response
+		if index == 0 {
+			initial, probe = probe, nil
+		}
+		worker := &segmentWorker{session: session, segment: segment}
+		workers.Add(1)
+		go func() {
+			defer workers.Done()
+			if err := worker.run(ctx, initial); err != nil {
+				firstFailure.Do(func() {
+					failure = err
+					cancel(err)
+				})
+			}
+		}()
+	}
+	closeBody(probe)
+	workers.Wait()
+	return failure
+}
+
+func (session *session) record(count int64) error {
+	session.request.Progress.Add(count)
+	if session.sinceSpaceCheck.Add(count) < spaceCheckInterval {
+		return nil
+	}
+	session.sinceSpaceCheck.Store(0)
+	return diskspace.EnsureFree(session.request.Directory, 0, session.request.ReservedBytes)
+}
+
+func (session *session) snapshot() State {
+	state := session.state
+	state.Segments = make([]Segment, len(session.segments))
+	for index, segment := range session.segments {
+		state.Segments[index] = segment.snapshot()
+	}
+	return state
+}
+
+func (session *session) saveCheckpoints(stop <-chan struct{}, stopped chan<- struct{}) {
+	defer close(stopped)
+	ticker := time.NewTicker(checkpointInterval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-stop:
+			return
+		case <-ticker.C:
+			session.saveCheckpoint()
+		}
+	}
+}
+
+func (session *session) saveCheckpoint() {
+	if session.request.Checkpoint == nil {
+		return
+	}
+	state := session.snapshot()
+	session.file.Sync()
+	session.request.Checkpoint(state)
+}

internal/fetch/state.go

@@ -0,0 +1,97 @@
+package fetch
+
+import "sync/atomic"
+
+const (
+	MaxConnections  = 16
+	minSegmentBytes = int64(32) << 20
+)
+
+type Segment struct {
+	Start int64 `json:"start"`
+	End   int64 `json:"end"`
+	Done  int64 `json:"done"`
+}
+
+type State struct {
+	FileName   string    `json:"fileName"`
+	Validator  string    `json:"validator"`
+	TotalBytes int64     `json:"totalBytes"`
+	Segments   []Segment `json:"segments"`
+}
+
+func (state State) DoneBytes() int64 {
+	var done int64
+	for _, segment := range state.Segments {
+		done += segment.Done
+	}
+	return done
+}
+
+func (state State) valid() bool {
+	if state.FileName == "" || len(state.Segments) == 0 {
+		return false
+	}
+	for _, segment := range state.Segments {
+		if segment.Start < 0 || segment.Done < 0 {
+			return false
+		}
+		if segment.End == 0 && state.TotalBytes > 0 {
+			return false
+		}
+		if segment.End > 0 && segment.Start+segment.Done > segment.End {
+			return false
+		}
+	}
+	return true
+}
+
+func planSegments(totalBytes int64, connections int) []Segment {
+	if totalBytes <= 0 {
+		return []Segment{{}}
+	}
+	count := min(int64(max(connections, 1)), max(totalBytes/minSegmentBytes, 1))
+	size := totalBytes / count
+	segments := make([]Segment, count)
+	for index := range segments {
+		start := int64(index) * size
+		segments[index] = Segment{Start: start, End: start + size}
+	}
+	segments[count-1].End = totalBytes
+	return segments
+}
+
+type liveSegment struct {
+	start int64
+	end   int64
+	done  atomic.Int64
+}
+
+func newLiveSegment(segment Segment) *liveSegment {
+	live := &liveSegment{start: segment.Start, end: segment.End}
+	live.done.Store(segment.Done)
+	return live
+}
+
+func (segment *liveSegment) position() int64 {
+	return segment.start + segment.done.Load()
+}
+
+func (segment *liveSegment) bounded() bool {
+	return segment.end > 0
+}
+
+func (segment *liveSegment) remaining() int64 {
+	if !segment.bounded() {
+		return -1
+	}
+	return segment.end - segment.position()
+}
+
+func (segment *liveSegment) complete() bool {
+	return segment.bounded() && segment.position() >= segment.end
+}
+
+func (segment *liveSegment) snapshot() Segment {
+	return Segment{Start: segment.start, End: segment.end, Done: segment.done.Load()}
+}

internal/fetch/worker.go

@@ -0,0 +1,107 @@
+package fetch
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+)
+
+const (
+	maxRetriesWithoutProgress = 8
+	retryBaseDelay            = 2 * time.Second
+	retryMaxDelay             = 30 * time.Second
+)
+
+type segmentWorker struct {
+	session        *session
+	segment        *liveSegment
+	failedAttempts int
+}
+
+func (worker *segmentWorker) run(ctx context.Context, response *http.Response) error {
+	var err error
+	if response == nil {
+		response, err = worker.open(ctx)
+	}
+	for {
+		if err != nil {
+			response, err = worker.reconnect(ctx, err)
+			if err != nil {
+				return err
+			}
+		}
+
+		doneBefore := worker.segment.done.Load()
+		err = worker.copyFrom(response)
+		if err == nil {
+			return nil
+		}
+		if worker.segment.done.Load() > doneBefore {
+			worker.failedAttempts = 0
+		}
+	}
+}
+
+func (worker *segmentWorker) open(ctx context.Context) (*http.Response, error) {
+	return worker.session.downloader.open(ctx, worker.session.source, worker.segment.position(), worker.segment.end)
+}
+
+func (worker *segmentWorker) copyFrom(response *http.Response) error {
+	defer response.Body.Close()
+	writer := io.NewOffsetWriter(worker.session.file, worker.segment.position())
+	if err := copyBody(writer, response.Body, worker.segment.remaining(), worker.record); err != nil {
+		return err
+	}
+	if worker.segment.bounded() && !worker.segment.complete() {
+		return ErrIncomplete
+	}
+	return nil
+}
+
+func (worker *segmentWorker) record(count int64) error {
+	worker.segment.done.Add(count)
+	return worker.session.record(count)
+}
+
+func (worker *segmentWorker) reconnect(ctx context.Context, cause error) (*http.Response, error) {
+	progress := worker.session.request.Progress
+	for {
+		worker.failedAttempts++
+		if ctx.Err() != nil || !isRetryable(cause) || worker.failedAttempts > maxRetriesWithoutProgress {
+			return nil, cause
+		}
+		progress.SetNotice(fmt.Sprintf("Connection lost, reconnecting (attempt %d of %d)", worker.failedAttempts, maxRetriesWithoutProgress))
+		if err := waitBeforeRetry(ctx, worker.failedAttempts); err != nil {
+			return nil, err
+		}
+
+		response, err := worker.open(ctx)
+		if err == nil {
+			progress.SetNotice("")
+			return response, nil
+		}
+		cause = err
+	}
+}
+
+func isRetryable(err error) bool {
+	return errors.Is(err, errConnectionFailed) ||
+		errors.Is(err, errServerUnavailable) ||
+		errors.Is(err, ErrStalled) ||
+		errors.Is(err, ErrIncomplete)
+}
+
+func waitBeforeRetry(ctx context.Context, attempt int) error {
+	delay := min(retryBaseDelay*time.Duration(attempt), retryMaxDelay)
+	timer := time.NewTimer(delay)
+	defer timer.Stop()
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	case <-timer.C:
+		return nil
+	}
+}

internal/files/internal.go

@@ -0,0 +1,41 @@
+package files
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+const (
+	PartFileName      = ".download.part"
+	JobFileName       = ".job.json"
+	temporaryPrefix   = ".ddc-tmp-"
+	temporaryWildcard = temporaryPrefix + "*"
+)
+
+func IsInternal(name string) bool {
+	return name == PartFileName || name == JobFileName || strings.HasPrefix(name, temporaryPrefix)
+}
+
+func WriteAtomically(path string, data []byte) error {
+	temporary, err := os.CreateTemp(filepath.Dir(path), temporaryWildcard)
+	if err != nil {
+		return err
+	}
+	_, writeErr := temporary.Write(data)
+	closeErr := temporary.Close()
+	if writeErr != nil || closeErr != nil {
+		os.Remove(temporary.Name())
+		return errors.Join(writeErr, closeErr)
+	}
+	if err := os.Chmod(temporary.Name(), 0o644); err != nil {
+		os.Remove(temporary.Name())
+		return err
+	}
+	if err := os.Rename(temporary.Name(), path); err != nil {
+		os.Remove(temporary.Name())
+		return err
+	}
+	return nil
+}

internal/files/paths.go

@@ -9,7 +9,6 @@ import (
 )
 
 const (
-	PartFileName      = ".download.part"
 	maxSubfolderDepth = 4
 	maxNameBytes      = 255
 )

internal/files/tree.go

@@ -41,7 +41,7 @@ func readLevel(root, relative string, depth int, entryCount *int) ([]Node, error
 			break
 		}
 		entryType := entry.Type()
-		if entry.Name() == PartFileName || (!entryType.IsDir() && !entryType.IsRegular()) {
+		if IsInternal(entry.Name()) || (!entryType.IsDir() && !entryType.IsRegular()) {
 			continue
 		}
 		*entryCount++

internal/history/history.go

@@ -0,0 +1,82 @@
+package history
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/fs"
+	"os"
+	"slices"
+	"sync"
+	"time"
+
+	"ddc/internal/files"
+)
+
+const maxEntries = 500
+
+type Entry struct {
+	FileName    string    `json:"fileName"`
+	SourceURL   string    `json:"sourceUrl"`
+	Destination string    `json:"destination"`
+	Items       []string  `json:"items"`
+	MovedAt     time.Time `json:"movedAt"`
+}
+
+type Store struct {
+	mutex   sync.Mutex
+	path    string
+	entries []Entry
+}
+
+func Open(path string) (*Store, error) {
+	store := &Store{path: path, entries: []Entry{}}
+	data, err := os.ReadFile(path)
+	if errors.Is(err, fs.ErrNotExist) {
+		return store, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	if err := json.Unmarshal(data, &store.entries); err != nil {
+		return nil, fmt.Errorf("history file %s: %w", path, err)
+	}
+	if store.entries == nil {
+		store.entries = []Entry{}
+	}
+	return store, nil
+}
+
+func (store *Store) List() []Entry {
+	store.mutex.Lock()
+	defer store.mutex.Unlock()
+	return slices.Clone(store.entries)
+}
+
+func (store *Store) Add(entry Entry) error {
+	store.mutex.Lock()
+	defer store.mutex.Unlock()
+	next := append([]Entry{entry}, store.entries...)
+	if len(next) > maxEntries {
+		next = next[:maxEntries]
+	}
+	return store.save(next)
+}
+
+func (store *Store) Clear() error {
+	store.mutex.Lock()
+	defer store.mutex.Unlock()
+	return store.save([]Entry{})
+}
+
+func (store *Store) save(entries []Entry) error {
+	data, err := json.MarshalIndent(entries, "", "  ")
+	if err != nil {
+		return err
+	}
+	if err := files.WriteAtomically(store.path, data); err != nil {
+		return err
+	}
+	store.entries = entries
+	return nil
+}

internal/jobs/download.go

@@ -0,0 +1,122 @@
+package jobs
+
+import (
+	"context"
+	"errors"
+	"path/filepath"
+
+	"ddc/internal/extract"
+	"ddc/internal/fetch"
+)
+
+func (manager *Manager) Pause(id string) error {
+	job, err := manager.lookup(id)
+	if err != nil {
+		return err
+	}
+	if !job.pause() {
+		return ErrJobBusy
+	}
+	return nil
+}
+
+func (manager *Manager) Resume(id string) error {
+	job, err := manager.lookup(id)
+	if err != nil {
+		return err
+	}
+	if !job.begin(StatusQueued, StatusPaused, StatusFailed) {
+		return ErrJobBusy
+	}
+	job.saveRecord()
+	manager.launchDownload(job)
+	return nil
+}
+
+func (manager *Manager) Reorder(id, direction string) error {
+	if direction != queueFirst && direction != queueUp && direction != queueDown {
+		return invalid(errors.New("direction must be first, up or down"))
+	}
+	job, err := manager.lookup(id)
+	if err != nil {
+		return err
+	}
+	if job.currentStatus() != StatusQueued || !manager.slots.reorder(id, direction) {
+		return ErrJobBusy
+	}
+	return nil
+}
+
+func (manager *Manager) launchDownload(job *Job) {
+	runContext, cancelRun := job.startRun()
+	manager.slots.enqueue(job.id)
+	go func() {
+		defer job.workers.Done()
+		defer cancelRun(nil)
+		manager.download(job, runContext)
+	}()
+}
+
+func (manager *Manager) download(job *Job, runContext context.Context) {
+	if !manager.slots.acquire(runContext, job.id, manager.concurrencyLimit) {
+		manager.handleDownloadError(job, runContext, context.Cause(runContext))
+		return
+	}
+	defer manager.slots.release()
+
+	job.setStatus(StatusDownloading, "")
+	filePath, err := manager.downloader.Download(runContext, manager.fetchRequest(job))
+	if err != nil {
+		manager.handleDownloadError(job, runContext, err)
+		return
+	}
+	job.markDownloaded(filepath.Base(filePath))
+
+	if job.autoExtract && extract.IsArchive(filePath) {
+		job.setStatus(StatusExtracting, "")
+		destination, err := manager.extractArchive(job, filePath)
+		if err != nil {
+			manager.finishWithError(job, StatusReady, "Extraction failed: ", err)
+			job.saveRecord()
+			return
+		}
+		job.SetFileName(filepath.Base(destination))
+	}
+
+	job.setStatus(StatusReady, "")
+	job.saveRecord()
+	manager.moveToTarget(job)
+}
+
+func (manager *Manager) fetchRequest(job *Job) fetch.Request {
+	current := manager.preferences.Get()
+	return fetch.Request{
+		URL:           job.sourceURL,
+		Directory:     job.directory,
+		FileName:      job.requestedName,
+		ReservedBytes: current.MinFreeBytes(),
+		Connections:   current.ConnectionsPerDownload,
+		State:         job.currentDownloadState(),
+		Progress:      job,
+		Checkpoint: func(state fetch.State) {
+			job.setDownloadState(&state)
+			job.saveRecord()
+		},
+	}
+}
+
+func (manager *Manager) handleDownloadError(job *Job, runContext context.Context, err error) {
+	switch {
+	case errors.Is(context.Cause(runContext), errPaused):
+		job.setStatus(StatusPaused, "")
+	case job.jobContext.Err() != nil:
+		job.setStatus(StatusCancelled, "")
+		return
+	default:
+		if errors.Is(err, fetch.ErrSourceChanged) || errors.Is(err, fetch.ErrResumeUnsupported) {
+			job.setDownloadState(nil)
+		}
+		job.setStatus(StatusFailed, err.Error())
+	}
+	job.saveRecord()
+}

internal/jobs/extraction.go

@@ -14,35 +14,6 @@ const maxArchiveEntries = 100000
 
 var errNotArchive = errors.New("selected file is not a supported archive")
 
-func (manager *Manager) download(job *Job) {
-	defer job.workers.Done()
-
-	if !manager.slots.acquire(job.jobContext, manager.concurrencyLimit) {
-		return
-	}
-	defer manager.slots.release()
-
-	job.setStatus(StatusDownloading, "")
-	filePath, err := manager.downloader.Download(job.jobContext, job.sourceURL, job.directory, manager.reservedBytes(), job)
-	if err != nil {
-		manager.finishWithError(job, StatusFailed, "", err)
-		return
-	}
-	job.SetFileName(filepath.Base(filePath))
-
-	if job.autoExtract && extract.IsArchive(filePath) {
-		job.setStatus(StatusExtracting, "")
-		destination, err := manager.extractArchive(job, filePath)
-		if err != nil {
-			manager.finishWithError(job, StatusReady, "Extraction failed: ", err)
-			return
-		}
-		job.SetFileName(filepath.Base(destination))
-	}
-
-	job.setStatus(StatusReady, "")
-}
-
 func (manager *Manager) Extract(id, relativePath string) error {
 	job, err := manager.lookup(id)
 	if err != nil {
@@ -58,7 +29,7 @@ func (manager *Manager) Extract(id, relativePath string) error {
 		return invalid(errNotArchive)
 	}
 
-	if !job.begin(StatusReady, StatusExtracting) {
+	if !job.begin(StatusExtracting, StatusReady) {
 		return ErrJobBusy
 	}
 	go func() {

internal/jobs/history.go

@@ -0,0 +1,33 @@
+package jobs
+
+import (
+	"log"
+	"time"
+
+	"ddc/internal/history"
+)
+
+func (manager *Manager) History() []history.Entry {
+	return manager.history.List()
+}
+
+func (manager *Manager) ClearHistory() error {
+	return manager.history.Clear()
+}
+
+func (manager *Manager) recordHistory(job *Job, destination string, movedNames []string) {
+	if len(movedNames) == 0 {
+		return
+	}
+	snapshot := job.snapshot()
+	entry := history.Entry{
+		FileName:    snapshot.FileName,
+		SourceURL:   snapshot.SourceURL,
+		Destination: destination,
+		Items:       movedNames,
+		MovedAt:     time.Now(),
+	}
+	if err := manager.history.Add(entry); err != nil {
+		log.Printf("could not save history: %v", err)
+	}
+}

internal/jobs/job.go

@@ -2,9 +2,12 @@ package jobs
 
 import (
 	"context"
+	"slices"
 	"sync"
 	"sync/atomic"
 	"time"
+
+	"ddc/internal/fetch"
 )
 
 type Status string
@@ -12,6 +15,7 @@ type Status string
 const (
 	StatusQueued      Status = "queued"
 	StatusDownloading Status = "downloading"
+	StatusPaused      Status = "paused"
 	StatusExtracting  Status = "extracting"
 	StatusReady       Status = "ready"
 	StatusMoving      Status = "moving"
@@ -21,56 +25,46 @@ const (
 )
 
 type Snapshot struct {
-	ID         string    `json:"id"`
-	SourceURL  string    `json:"sourceUrl"`
-	FileName   string    `json:"fileName"`
-	Status     Status    `json:"status"`
-	Message    string    `json:"message"`
-	BytesDone  int64     `json:"bytesDone"`
-	BytesTotal int64     `json:"bytesTotal"`
-	CreatedAt  time.Time `json:"createdAt"`
+	ID            string    `json:"id"`
+	SourceURL     string    `json:"sourceUrl"`
+	FileName      string    `json:"fileName"`
+	Status        Status    `json:"status"`
+	Message       string    `json:"message"`
+	BytesDone     int64     `json:"bytesDone"`
+	BytesTotal    int64     `json:"bytesTotal"`
+	CreatedAt     time.Time `json:"createdAt"`
+	MoveTarget    string    `json:"moveTarget,omitempty"`
+	QueuePosition int       `json:"queuePosition,omitempty"`
 }
 
 type Job struct {
-	id          string
-	sourceURL   string
-	displayURL  string
-	directory   string
-	autoExtract bool
-	createdAt   time.Time
-	jobContext  context.Context
-	cancel      context.CancelFunc
-	workers     sync.WaitGroup
+	id            string
+	sourceURL     string
+	displayURL    string
+	directory     string
+	requestedName string
+	autoExtract   bool
+	target        *moveTarget
+	createdAt     time.Time
+	jobContext    context.Context
+	cancel        context.CancelFunc
+	workers       sync.WaitGroup
 
-	mutex    sync.Mutex
-	status   Status
-	message  string
-	fileName string
-	deleted  bool
+	mutex         sync.Mutex
+	status        Status
+	message       string
+	fileName      string
+	deleted       bool
+	downloaded    bool
+	downloadState *fetch.State
+	cancelRun     context.CancelCauseFunc
+
+	recordMutex sync.Mutex
 
 	bytesDone  atomic.Int64
 	bytesTotal atomic.Int64
 }
 
-func (job *Job) SetTotal(total int64) {
-	job.bytesTotal.Store(total)
-}
-
-func (job *Job) Add(delta int64) {
-	job.bytesDone.Add(delta)
-}
-
-func (job *Job) SetFileName(name string) {
-	job.mutex.Lock()
-	defer job.mutex.Unlock()
-	job.fileName = name
-}
-
-func (job *Job) resetProgress() {
-	job.bytesDone.Store(0)
-	job.bytesTotal.Store(0)
-}
-
 func (job *Job) setStatus(status Status, message string) {
 	job.mutex.Lock()
 	defer job.mutex.Unlock()
@@ -87,10 +81,10 @@ func (job *Job) currentStatus() Status {
 	return job.status
 }
 
-func (job *Job) begin(from, to Status) bool {
+func (job *Job) begin(to Status, allowedFrom ...Status) bool {
 	job.mutex.Lock()
 	defer job.mutex.Unlock()
-	if job.deleted || job.status != from {
+	if job.deleted || !slices.Contains(allowedFrom, job.status) {
 		return false
 	}
 	job.status = to
@@ -113,6 +107,10 @@ func (job *Job) markDeleted() bool {
 func (job *Job) snapshot() Snapshot {
 	job.mutex.Lock()
 	defer job.mutex.Unlock()
+	moveTargetPath := ""
+	if job.target != nil {
+		moveTargetPath = job.target.displayPath()
+	}
 	return Snapshot{
 		ID:         job.id,
 		SourceURL:  job.displayURL,
@@ -122,5 +120,6 @@ func (job *Job) snapshot() Snapshot {
 		BytesDone:  job.bytesDone.Load(),
 		BytesTotal: job.bytesTotal.Load(),
 		CreatedAt:  job.createdAt,
+		MoveTarget: moveTargetPath,
 	}
 }

internal/jobs/manager.go

@@ -10,6 +10,7 @@ import (
 	"path"
 	"path/filepath"
 	"sort"
+	"strings"
 	"sync"
 	"time"
 
@@ -18,6 +19,7 @@ import (
 	"ddc/internal/fetch"
 	"ddc/internal/files"
 	"ddc/internal/guard"
+	"ddc/internal/history"
 	"ddc/internal/libraries"
 	"ddc/internal/preferences"
 )
@@ -31,6 +33,7 @@ var (
 type Manager struct {
 	settings    config.Settings
 	preferences *preferences.Store
+	history     *history.Store
 	policy      *guard.Policy
 	downloader  *fetch.Downloader
 	rootContext context.Context
@@ -40,12 +43,13 @@ type Manager struct {
 	jobs        map[string]*Job
 }
 
-func NewManager(settings config.Settings, store *preferences.Store) *Manager {
+func NewManager(settings config.Settings, store *preferences.Store, historyStore *history.Store) *Manager {
 	policy := guard.NewPolicy(store.Get().AllowedPorts)
 	rootContext, cancelAll := context.WithCancel(context.Background())
 	return &Manager{
 		settings:    settings,
 		preferences: store,
+		history:     historyStore,
 		policy:      policy,
 		downloader:  fetch.NewDownloader(policy),
 		rootContext: rootContext,
@@ -63,6 +67,11 @@ func (manager *Manager) Preferences() preferences.Preferences {
 }
 
 func (manager *Manager) UpdatePreferences(next preferences.Preferences) error {
+	downloadPaths, err := manager.normalizeDownloadPaths(next.DownloadPaths)
+	if err != nil {
+		return err
+	}
+	next.DownloadPaths = downloadPaths
 	if err := manager.preferences.Update(next); err != nil {
 		return err
 	}
@@ -82,11 +91,27 @@ func (manager *Manager) AvailableBytes() (int64, error) {
 	return diskspace.Available(manager.settings.DownloadDir)
 }
 
-func (manager *Manager) Create(rawURL string, autoExtract bool) (Snapshot, error) {
-	target, err := manager.policy.ValidateURL(rawURL)
+type CreateRequest struct {
+	URL         string `json:"url"`
+	FileName    string `json:"fileName"`
+	AutoExtract bool   `json:"autoExtract"`
+	Destination string `json:"destination"`
+	Subfolder   string `json:"subfolder"`
+}
+
+func (manager *Manager) Create(request CreateRequest) (Snapshot, error) {
+	target, err := manager.policy.ValidateURL(request.URL)
 	if err != nil {
 		return Snapshot{}, invalid(err)
 	}
+	requestedName := fetch.SanitizeFileName(request.FileName)
+	if strings.TrimSpace(request.FileName) != "" && requestedName == "" {
+		return Snapshot{}, invalid(errors.New("file name is not allowed"))
+	}
+	moveTarget, err := manager.resolveTarget(request.Destination, request.Subfolder)
+	if err != nil {
+		return Snapshot{}, err
+	}
 	if err := diskspace.EnsureFree(manager.settings.DownloadDir, 0, manager.reservedBytes()); err != nil {
 		return Snapshot{}, err
 	}
@@ -103,13 +128,16 @@ func (manager *Manager) Create(rawURL string, autoExtract bool) (Snapshot, error
 	job := manager.newJob(id, directory, time.Now())
 	job.sourceURL = target.String()
 	job.displayURL = target.Redacted()
-	job.autoExtract = autoExtract
+	job.requestedName = requestedName
+	job.autoExtract = request.AutoExtract
+	job.target = moveTarget
 	job.status = StatusQueued
-	job.fileName = initialFileName(target.Path, target.Host)
+	job.fileName = initialFileName(requestedName, target.Path, target.Host)
 	job.workers.Add(1)
 
 	manager.store(job)
-	go manager.download(job)
+	job.saveRecord()
+	manager.launchDownload(job)
 	return job.snapshot(), nil
 }
 
@@ -117,7 +145,11 @@ func (manager *Manager) List() []Snapshot {
 	manager.mutex.RLock()
 	snapshots := make([]Snapshot, 0, len(manager.jobs))
 	for _, job := range manager.jobs {
-		snapshots = append(snapshots, job.snapshot())
+		snapshot := job.snapshot()
+		if snapshot.Status == StatusQueued {
+			snapshot.QueuePosition = manager.slots.position(job.id)
+		}
+		snapshots = append(snapshots, snapshot)
 	}
 	manager.mutex.RUnlock()
 
@@ -157,8 +189,26 @@ func (manager *Manager) Delete(id string) error {
 	return os.RemoveAll(job.directory)
 }
 
-func (manager *Manager) CancelAll() {
+func (manager *Manager) Shutdown(ctx context.Context) {
 	manager.cancelAll()
+	manager.mutex.RLock()
+	allJobs := make([]*Job, 0, len(manager.jobs))
+	for _, job := range manager.jobs {
+		allJobs = append(allJobs, job)
+	}
+	manager.mutex.RUnlock()
+
+	finished := make(chan struct{})
+	go func() {
+		for _, job := range allJobs {
+			job.workers.Wait()
+		}
+		close(finished)
+	}()
+	select {
+	case <-finished:
+	case <-ctx.Done():
+	}
 }
 
 func (manager *Manager) newJob(id, directory string, createdAt time.Time) *Job {
@@ -196,7 +246,10 @@ func newJobID() (string, error) {
 	return hex.EncodeToString(buffer), nil
 }
 
-func initialFileName(urlPath, host string) string {
+func initialFileName(requestedName, urlPath, host string) string {
+	if requestedName != "" {
+		return requestedName
+	}
 	if name := fetch.SanitizeFileName(path.Base(urlPath)); name != "" {
 		return name
 	}

internal/jobs/move.go

@@ -7,7 +7,6 @@ import (
 	"path/filepath"
 
 	"ddc/internal/files"
-	"ddc/internal/libraries"
 )
 
 type MoveRequest struct {
@@ -29,19 +28,18 @@ func (manager *Manager) Move(id string, request MoveRequest) error {
 		return invalid(errors.New("select at least one file or folder"))
 	}
 
-	library, err := libraries.Resolve(manager.settings.LibraryRoots, request.Destination)
+	target, err := manager.resolveTarget(request.Destination, request.Subfolder)
 	if err != nil {
-		return invalid(err)
+		return err
 	}
-	subfolder, err := files.SanitizeSubfolder(request.Subfolder)
-	if err != nil {
-		return invalid(err)
+	if target == nil {
+		return invalid(errors.New("choose a destination"))
 	}
 	sources, err := resolveSources(job.directory, request.Paths)
 	if err != nil {
 		return err
 	}
-	destination, err := files.EnsureSubdirectory(library.Path, subfolder)
+	destination, err := files.EnsureSubdirectory(target.destination, target.subfolder)
 	if err != nil {
 		return invalid(err)
 	}
@@ -49,12 +47,12 @@ func (manager *Manager) Move(id string, request MoveRequest) error {
 		return err
 	}
 
-	if !job.begin(StatusReady, StatusMoving) {
+	if !job.begin(StatusMoving, StatusReady) {
 		return ErrJobBusy
 	}
 	go func() {
 		defer job.workers.Done()
-		manager.moveFiles(job, library, sources, destination, request.Cleanup)
+		manager.moveFiles(job, sources, destination, request.Cleanup)
 	}()
 	return nil
 }
@@ -69,6 +67,9 @@ func resolveSources(root string, relativePaths []string) ([]string, error) {
 			return nil, invalid(err)
 		}
 		name := filepath.Base(source)
+		if files.IsInternal(name) {
+			return nil, invalid(files.ErrUnsafePath)
+		}
 		if seenNames[name] {
 			return nil, invalid(fmt.Errorf("more than one selected item is named %q", name))
 		}
@@ -96,7 +97,7 @@ func checkTargets(sources []string, destination string) error {
 	return nil
 }
 
-func (manager *Manager) moveFiles(job *Job, library libraries.Destination, sources []string, destination string, cleanup bool) {
+func (manager *Manager) moveFiles(job *Job, sources []string, destination string, cleanup bool) {
 	job.resetProgress()
 	var totalBytes int64
 	for _, source := range sources {
@@ -106,14 +107,17 @@ func (manager *Manager) moveFiles(job *Job, library libraries.Destination, sourc
 	}
 	job.SetTotal(totalBytes)
 
+	movedNames := make([]string, 0, len(sources))
+	defer func() { manager.recordHistory(job, destination, movedNames) }()
 	for _, source := range sources {
 		if err := files.MoveInto(source, destination, manager.reservedBytes(), job.Add); err != nil {
 			job.setStatus(StatusReady, "Move failed: "+err.Error())
 			return
 		}
+		movedNames = append(movedNames, filepath.Base(source))
 	}
 
-	message := fmt.Sprintf("Moved %d item(s) to %s", len(sources), library.Path)
+	message := fmt.Sprintf("Moved %d item(s) to %s", len(sources), destination)
 	if !cleanup {
 		job.setStatus(StatusReady, message)
 		return

internal/jobs/progress.go

@@ -0,0 +1,79 @@
+package jobs
+
+import (
+	"context"
+	"errors"
+
+	"ddc/internal/fetch"
+)
+
+var errPaused = errors.New("download paused")
+
+func (job *Job) SetTotal(total int64) {
+	job.bytesTotal.Store(total)
+}
+
+func (job *Job) SetDone(done int64) {
+	job.bytesDone.Store(done)
+}
+
+func (job *Job) Add(delta int64) {
+	job.bytesDone.Add(delta)
+}
+
+func (job *Job) SetFileName(name string) {
+	job.mutex.Lock()
+	defer job.mutex.Unlock()
+	job.fileName = name
+}
+
+func (job *Job) SetNotice(text string) {
+	job.mutex.Lock()
+	defer job.mutex.Unlock()
+	if !job.deleted && job.status == StatusDownloading {
+		job.message = text
+	}
+}
+
+func (job *Job) resetProgress() {
+	job.bytesDone.Store(0)
+	job.bytesTotal.Store(0)
+}
+
+func (job *Job) startRun() (context.Context, context.CancelCauseFunc) {
+	runContext, cancelRun := context.WithCancelCause(job.jobContext)
+	job.mutex.Lock()
+	defer job.mutex.Unlock()
+	job.cancelRun = cancelRun
+	return runContext, cancelRun
+}
+
+func (job *Job) pause() bool {
+	job.mutex.Lock()
+	defer job.mutex.Unlock()
+	if job.cancelRun == nil || (job.status != StatusQueued && job.status != StatusDownloading) {
+		return false
+	}
+	job.cancelRun(errPaused)
+	return true
+}
+
+func (job *Job) currentDownloadState() *fetch.State {
+	job.mutex.Lock()
+	defer job.mutex.Unlock()
+	return job.downloadState
+}
+
+func (job *Job) setDownloadState(state *fetch.State) {
+	job.mutex.Lock()
+	defer job.mutex.Unlock()
+	job.downloadState = state
+}
+
+func (job *Job) markDownloaded(fileName string) {
+	job.mutex.Lock()
+	defer job.mutex.Unlock()
+	job.downloaded = true
+	job.downloadState = nil
+	job.fileName = fileName
+}

internal/jobs/record.go

@@ -0,0 +1,106 @@
+package jobs
+
+import (
+	"encoding/json"
+	"log"
+	"os"
+	"path/filepath"
+	"time"
+
+	"ddc/internal/fetch"
+	"ddc/internal/files"
+)
+
+const (
+	phaseDownloading = "downloading"
+	phasePaused      = "paused"
+	phaseFailed      = "failed"
+	phaseDone        = "done"
+)
+
+type jobRecord struct {
+	SourceURL     string       `json:"sourceUrl"`
+	DisplayURL    string       `json:"displayUrl"`
+	RequestedName string       `json:"requestedName,omitempty"`
+	FileName      string       `json:"fileName"`
+	AutoExtract   bool         `json:"autoExtract"`
+	Destination   string       `json:"destination,omitempty"`
+	Subfolder     string       `json:"subfolder,omitempty"`
+	Phase         string       `json:"phase"`
+	Message       string       `json:"message,omitempty"`
+	Download      *fetch.State `json:"download,omitempty"`
+	CreatedAt     time.Time    `json:"createdAt"`
+}
+
+func (job *Job) record() jobRecord {
+	job.mutex.Lock()
+	defer job.mutex.Unlock()
+	record := jobRecord{
+		SourceURL:     job.sourceURL,
+		DisplayURL:    job.displayURL,
+		RequestedName: job.requestedName,
+		FileName:      job.fileName,
+		AutoExtract:   job.autoExtract,
+		Phase:         phaseFor(job.status, job.downloaded),
+		Message:       job.message,
+		Download:      job.downloadState,
+		CreatedAt:     job.createdAt,
+	}
+	if job.target != nil {
+		record.Destination = job.target.destination
+		record.Subfolder = job.target.subfolder
+	}
+	return record
+}
+
+func phaseFor(status Status, downloaded bool) string {
+	switch {
+	case downloaded:
+		return phaseDone
+	case status == StatusPaused:
+		return phasePaused
+	case status == StatusFailed:
+		return phaseFailed
+	default:
+		return phaseDownloading
+	}
+}
+
+func (job *Job) saveRecord() {
+	data, err := json.MarshalIndent(job.record(), "", "  ")
+	if err != nil {
+		log.Printf("could not encode download %s: %v", job.id, err)
+		return
+	}
+	job.recordMutex.Lock()
+	defer job.recordMutex.Unlock()
+	if err := files.WriteAtomically(filepath.Join(job.directory, files.JobFileName), data); err != nil && !os.IsNotExist(err) {
+		log.Printf("could not save download %s: %v", job.id, err)
+	}
+}
+
+func readRecord(directory string) (jobRecord, bool) {
+	data, err := os.ReadFile(filepath.Join(directory, files.JobFileName))
+	if err != nil {
+		return jobRecord{}, false
+	}
+	var record jobRecord
+	if err := json.Unmarshal(data, &record); err != nil {
+		return jobRecord{}, false
+	}
+	return record, true
+}
+
+func (job *Job) applyRecord(record jobRecord) {
+	job.sourceURL = record.SourceURL
+	job.displayURL = record.DisplayURL
+	job.requestedName = record.RequestedName
+	job.fileName = record.FileName
+	job.autoExtract = record.AutoExtract
+	if !record.CreatedAt.IsZero() {
+		job.createdAt = record.CreatedAt
+	}
+	if record.Destination != "" {
+		job.target = &moveTarget{destination: record.Destination, subfolder: record.Subfolder}
+	}
+}

internal/jobs/restore.go

@@ -1,9 +1,11 @@
 package jobs
 
 import (
+	"io/fs"
 	"os"
 	"path/filepath"
 	"regexp"
+	"sort"
 	"time"
 
 	"ddc/internal/files"
@@ -17,33 +19,72 @@ func (manager *Manager) RestoreExisting() error {
 		return err
 	}
 
+	var queuedJobs []*Job
 	for _, entry := range entries {
 		if !entry.IsDir() || !jobIDPattern.MatchString(entry.Name()) {
 			continue
 		}
-		directory := filepath.Join(manager.settings.DownloadDir, entry.Name())
-		os.Remove(filepath.Join(directory, files.PartFileName))
-
-		createdAt := time.Now()
-		if info, err := entry.Info(); err == nil {
-			createdAt = info.ModTime()
-		}
-
-		job := manager.newJob(entry.Name(), directory, createdAt)
-		job.status = StatusReady
-		job.fileName = firstEntryName(directory, entry.Name())
+		job := manager.restoreJob(entry)
 		manager.store(job)
+		if job.status == StatusQueued {
+			queuedJobs = append(queuedJobs, job)
+		}
+	}
+
+	sort.Slice(queuedJobs, func(first, second int) bool {
+		return queuedJobs[first].createdAt.Before(queuedJobs[second].createdAt)
+	})
+	for _, job := range queuedJobs {
+		job.workers.Add(1)
+		manager.launchDownload(job)
 	}
 	return nil
 }
 
+func (manager *Manager) restoreJob(entry fs.DirEntry) *Job {
+	directory := filepath.Join(manager.settings.DownloadDir, entry.Name())
+	createdAt := time.Now()
+	if info, err := entry.Info(); err == nil {
+		createdAt = info.ModTime()
+	}
+	job := manager.newJob(entry.Name(), directory, createdAt)
+
+	record, found := readRecord(directory)
+	if found {
+		job.applyRecord(record)
+	}
+	if !found || record.Phase == phaseDone {
+		os.Remove(filepath.Join(directory, files.PartFileName))
+		job.status = StatusReady
+		job.downloaded = true
+		job.fileName = firstEntryName(directory, entry.Name())
+		return job
+	}
+
+	job.downloadState = record.Download
+	if record.Download != nil {
+		job.bytesDone.Store(record.Download.DoneBytes())
+		job.bytesTotal.Store(record.Download.TotalBytes)
+	}
+	switch record.Phase {
+	case phasePaused:
+		job.status = StatusPaused
+	case phaseFailed:
+		job.status = StatusFailed
+		job.message = record.Message
+	default:
+		job.status = StatusQueued
+	}
+	return job
+}
+
 func firstEntryName(directory, fallback string) string {
 	entries, err := os.ReadDir(directory)
 	if err != nil {
 		return fallback
 	}
 	for _, entry := range entries {
-		if entry.Name() != files.PartFileName {
+		if !files.IsInternal(entry.Name()) {
 			return entry.Name()
 		}
 	}

internal/jobs/slots.go

@@ -2,38 +2,57 @@ package jobs
 
 import (
 	"context"
+	"slices"
 	"sync"
 	"time"
 )
 
 const slotWaitInterval = 500 * time.Millisecond
 
+const (
+	queueFirst = "first"
+	queueUp    = "up"
+	queueDown  = "down"
+)
+
 type slotLimiter struct {
-	mutex  sync.Mutex
-	active int
+	mutex   sync.Mutex
+	active  int
+	waiting []string
 }
 
-func (limiter *slotLimiter) acquire(ctx context.Context, limit func() int) bool {
+func (limiter *slotLimiter) enqueue(id string) {
+	limiter.mutex.Lock()
+	defer limiter.mutex.Unlock()
+	if !slices.Contains(limiter.waiting, id) {
+		limiter.waiting = append(limiter.waiting, id)
+	}
+}
+
+func (limiter *slotLimiter) acquire(ctx context.Context, id string, limit func() int) bool {
+	limiter.enqueue(id)
 	ticker := time.NewTicker(slotWaitInterval)
 	defer ticker.Stop()
 	for {
-		if limiter.tryAcquire(limit()) {
+		if limiter.tryAcquire(id, limit()) {
 			return true
 		}
 		select {
 		case <-ctx.Done():
+			limiter.remove(id)
 			return false
 		case <-ticker.C:
 		}
 	}
 }
 
-func (limiter *slotLimiter) tryAcquire(limit int) bool {
+func (limiter *slotLimiter) tryAcquire(id string, limit int) bool {
 	limiter.mutex.Lock()
 	defer limiter.mutex.Unlock()
-	if limiter.active >= limit {
+	if limiter.active >= limit || len(limiter.waiting) == 0 || limiter.waiting[0] != id {
 		return false
 	}
+	limiter.waiting = limiter.waiting[1:]
 	limiter.active++
 	return true
 }
@@ -43,3 +62,39 @@ func (limiter *slotLimiter) release() {
 	defer limiter.mutex.Unlock()
 	limiter.active--
 }
+
+func (limiter *slotLimiter) remove(id string) {
+	limiter.mutex.Lock()
+	defer limiter.mutex.Unlock()
+	limiter.waiting = slices.DeleteFunc(limiter.waiting, func(waitingID string) bool {
+		return waitingID == id
+	})
+}
+
+func (limiter *slotLimiter) position(id string) int {
+	limiter.mutex.Lock()
+	defer limiter.mutex.Unlock()
+	return slices.Index(limiter.waiting, id) + 1
+}
+
+func (limiter *slotLimiter) reorder(id, direction string) bool {
+	limiter.mutex.Lock()
+	defer limiter.mutex.Unlock()
+	index := slices.Index(limiter.waiting, id)
+	if index < 0 {
+		return false
+	}
+
+	target := index
+	switch direction {
+	case queueFirst:
+		target = 0
+	case queueUp:
+		target = max(index-1, 0)
+	case queueDown:
+		target = min(index+1, len(limiter.waiting)-1)
+	}
+	limiter.waiting = slices.Delete(limiter.waiting, index, index+1)
+	limiter.waiting = slices.Insert(limiter.waiting, target, id)
+	return true
+}

internal/jobs/target.go

@@ -0,0 +1,109 @@
+package jobs
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"ddc/internal/files"
+	"ddc/internal/libraries"
+	"ddc/internal/preferences"
+)
+
+type moveTarget struct {
+	destination string
+	subfolder   string
+}
+
+func (target *moveTarget) displayPath() string {
+	return filepath.Join(target.destination, target.subfolder)
+}
+
+func (manager *Manager) resolveTarget(destination, subfolder string) (*moveTarget, error) {
+	if strings.TrimSpace(destination) == "" {
+		return nil, nil
+	}
+	libraryPath, extraFolder, err := manager.splitDownloadPath(destination)
+	if err != nil {
+		return nil, invalid(err)
+	}
+	cleanSubfolder, err := files.SanitizeSubfolder(subfolder)
+	if err != nil {
+		return nil, invalid(err)
+	}
+	combinedSubfolder, err := files.SanitizeSubfolder(extraFolder + "/" + cleanSubfolder)
+	if err != nil {
+		return nil, invalid(err)
+	}
+	return &moveTarget{destination: libraryPath, subfolder: combinedSubfolder}, nil
+}
+
+func (manager *Manager) splitDownloadPath(fullPath string) (string, string, error) {
+	cleaned := filepath.Clean(strings.TrimSpace(fullPath))
+	for _, root := range manager.settings.LibraryRoots {
+		if !files.IsWithin(root, cleaned) {
+			continue
+		}
+		relative, err := filepath.Rel(root, cleaned)
+		if err != nil {
+			return "", "", err
+		}
+		libraryName, extraFolder, _ := strings.Cut(filepath.ToSlash(relative), "/")
+		library, err := libraries.Resolve(manager.settings.LibraryRoots, filepath.Join(root, libraryName))
+		if err != nil {
+			return "", "", err
+		}
+		return library.Path, extraFolder, nil
+	}
+	return "", "", libraries.ErrUnknownDestination
+}
+
+func (manager *Manager) normalizeDownloadPaths(downloadPaths []string) ([]string, error) {
+	normalized := make([]string, 0, len(downloadPaths))
+	seenPaths := make(map[string]bool)
+	for _, downloadPath := range downloadPaths {
+		target, err := manager.resolveTarget(downloadPath, "")
+		if err != nil || target == nil {
+			return nil, fmt.Errorf("%w: %q is not inside a destination folder", preferences.ErrInvalid, downloadPath)
+		}
+		fullPath := target.displayPath()
+		if !seenPaths[fullPath] {
+			seenPaths[fullPath] = true
+			normalized = append(normalized, fullPath)
+		}
+	}
+	return normalized, nil
+}
+
+func (manager *Manager) moveToTarget(job *Job) {
+	if job.target == nil {
+		return
+	}
+	names, err := topLevelNames(job.directory)
+	if err == nil {
+		err = manager.Move(job.id, MoveRequest{
+			Paths:       names,
+			Destination: job.target.destination,
+			Subfolder:   job.target.subfolder,
+			Cleanup:     true,
+		})
+	}
+	if err != nil {
+		job.setStatus(StatusReady, "Move failed: "+err.Error())
+	}
+}
+
+func topLevelNames(directory string) ([]string, error) {
+	entries, err := os.ReadDir(directory)
+	if err != nil {
+		return nil, err
+	}
+	names := make([]string, 0, len(entries))
+	for _, entry := range entries {
+		if !files.IsInternal(entry.Name()) {
+			names = append(names, entry.Name())
+		}
+	}
+	return names, nil
+}

internal/libraries/libraries.go

@@ -5,14 +5,17 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+
+	"ddc/internal/diskspace"
 )
 
 var ErrUnknownDestination = errors.New("destination is not a first level folder of a library root")
 
 type Destination struct {
-	Name string `json:"name"`
-	Root string `json:"root"`
-	Path string `json:"path"`
+	Name      string `json:"name"`
+	Root      string `json:"root"`
+	Path      string `json:"path"`
+	FreeBytes int64  `json:"freeBytes"`
 }
 
 func Discover(roots []string) []Destination {
@@ -26,10 +29,16 @@ func Discover(roots []string) []Destination {
 			if !entry.IsDir() || strings.HasPrefix(entry.Name(), ".") {
 				continue
 			}
+			path := filepath.Join(root, entry.Name())
+			freeBytes, err := diskspace.Available(path)
+			if err != nil {
+				freeBytes = -1
+			}
 			destinations = append(destinations, Destination{
-				Name: entry.Name(),
-				Root: root,
-				Path: filepath.Join(root, entry.Name()),
+				Name:      entry.Name(),
+				Root:      root,
+				Path:      path,
+				FreeBytes: freeBytes,
 			})
 		}
 	}

internal/preferences/preferences.go

@@ -3,22 +3,27 @@ package preferences
 import (
 	"errors"
 	"fmt"
+	"path/filepath"
 )
 
 const (
 	gigabyte             = int64(1) << 30
 	maxConcurrentLimit   = 10
+	maxConnectionsLimit  = 16
 	maxReservedGigabytes = 100000
+	maxDownloadPaths     = 50
 )
 
 var ErrInvalid = errors.New("invalid settings")
 
 type Preferences struct {
 	MaxConcurrentDownloads int      `json:"maxConcurrentDownloads"`
+	ConnectionsPerDownload int      `json:"connectionsPerDownload"`
 	MinFreeGB              int      `json:"minFreeGB"`
 	AllowedPorts           []uint16 `json:"allowedPorts"`
 	AutoExtract            bool     `json:"autoExtract"`
 	CleanupAfterMove       bool     `json:"cleanupAfterMove"`
+	DownloadPaths          []string `json:"downloadPaths"`
 }
 
 func (preferences Preferences) MinFreeBytes() int64 {
@@ -29,7 +34,10 @@ func (preferences Preferences) Validate() error {
 	if preferences.MaxConcurrentDownloads < 1 || preferences.MaxConcurrentDownloads > maxConcurrentLimit {
 		return fmt.Errorf("%w: parallel downloads must be between 1 and %d", ErrInvalid, maxConcurrentLimit)
 	}
-	if preferences.MinFreeGB < 0 || preferences.MinFreeGB > maxReservedGigabytes {
+	if preferences.ConnectionsPerDownload < 1 || preferences.ConnectionsPerDownload > maxConnectionsLimit {
+		return fmt.Errorf("%w: connections per download must be between 1 and %d", ErrInvalid, maxConnectionsLimit)
+	}
+	if preferences.MinFreeGB < 0|| preferences.MinFreeGB > maxReservedGigabytes {
 		return fmt.Errorf("%w: free space to keep must be between 0 and %d GB", ErrInvalid, maxReservedGigabytes)
 	}
 	for _, port := range preferences.AllowedPorts {
@@ -37,5 +45,13 @@ func (preferences Preferences) Validate() error {
 			return fmt.Errorf("%w: port 0 is not allowed", ErrInvalid)
 		}
 	}
+	if len(preferences.DownloadPaths) > maxDownloadPaths {
+		return fmt.Errorf("%w: at most %d download paths are allowed", ErrInvalid, maxDownloadPaths)
+	}
+	for _, downloadPath := range preferences.DownloadPaths {
+		if !filepath.IsAbs(downloadPath) {
+			return fmt.Errorf("%w: download path %q must be an absolute path", ErrInvalid, downloadPath)
+		}
+	}
 	return nil
 }

internal/preferences/store.go

@@ -6,9 +6,10 @@ import (
 	"fmt"
 	"io/fs"
 	"os"
-	"path/filepath"
 	"slices"
 	"sync"
+
+	"ddc/internal/files"
 )
 
 type Store struct {
@@ -47,6 +48,10 @@ func (store *Store) Get() Preferences {
 	if current.AllowedPorts == nil {
 		current.AllowedPorts = []uint16{}
 	}
+	current.DownloadPaths = slices.Clone(current.DownloadPaths)
+	if current.DownloadPaths == nil {
+		current.DownloadPaths = []string{}
+	}
 	return current
 }
 
@@ -61,27 +66,9 @@ func (store *Store) Update(next Preferences) error {
 
 	store.mutex.Lock()
 	defer store.mutex.Unlock()
-	if err := writeAtomically(store.path, data); err != nil {
+	if err := files.WriteAtomically(store.path, data); err != nil {
 		return err
 	}
 	store.current = next
 	return nil
 }
-
-func writeAtomically(path string, data []byte) error {
-	temporary, err := os.CreateTemp(filepath.Dir(path), ".settings-*.tmp")
-	if err != nil {
-		return err
-	}
-	_, writeErr := temporary.Write(data)
-	closeErr := temporary.Close()
-	if writeErr != nil || closeErr != nil {
-		os.Remove(temporary.Name())
-		return errors.Join(writeErr, closeErr)
-	}
-	if err := os.Rename(temporary.Name(), path); err != nil {
-		os.Remove(temporary.Name())
-		return err
-	}
-	return nil
-}

internal/server/control_handlers.go

@@ -0,0 +1,48 @@
+package server
+
+import "net/http"
+
+func (server *Server) handlePause(writer http.ResponseWriter, request *http.Request) {
+	if err := server.manager.Pause(request.PathValue("id")); err != nil {
+		writeFailure(writer, err)
+		return
+	}
+	writeJSON(writer, http.StatusAccepted, startedResponse{Started: true})
+}
+
+func (server *Server) handleResume(writer http.ResponseWriter, request *http.Request) {
+	if err := server.manager.Resume(request.PathValue("id")); err != nil {
+		writeFailure(writer, err)
+		return
+	}
+	writeJSON(writer, http.StatusAccepted, startedResponse{Started: true})
+}
+
+type reorderRequest struct {
+	Direction string `json:"direction"`
+}
+
+func (server *Server) handleReorder(writer http.ResponseWriter, request *http.Request) {
+	var body reorderRequest
+	if err := decodeJSON(request, &body); err != nil {
+		writeError(writer, http.StatusBadRequest, "invalid request body")
+		return
+	}
+	if err := server.manager.Reorder(request.PathValue("id"), body.Direction); err != nil {
+		writeFailure(writer, err)
+		return
+	}
+	writeJSON(writer, http.StatusOK, startedResponse{Started: true})
+}
+
+func (server *Server) handleHistory(writer http.ResponseWriter, _ *http.Request) {
+	writeJSON(writer, http.StatusOK, server.manager.History())
+}
+
+func (server *Server) handleClearHistory(writer http.ResponseWriter, _ *http.Request) {
+	if err := server.manager.ClearHistory(); err != nil {
+		writeFailure(writer, err)
+		return
+	}
+	writer.WriteHeader(http.StatusNoContent)
+}

internal/server/job_handlers.go

@@ -6,11 +6,6 @@ import (
 	"ddc/internal/jobs"
 )
 
-type createJobRequest struct {
-	URL         string `json:"url"`
-	AutoExtract bool   `json:"autoExtract"`
-}
-
 type extractRequest struct {
 	Path string `json:"path"`
 }
@@ -42,12 +37,12 @@ func (server *Server) handleListJobs(writer http.ResponseWriter, _ *http.Request
 }
 
 func (server *Server) handleCreateJob(writer http.ResponseWriter, request *http.Request) {
-	var body createJobRequest
+	var body jobs.CreateRequest
 	if err := decodeJSON(request, &body); err != nil {
 		writeError(writer, http.StatusBadRequest, "invalid request body")
 		return
 	}
-	snapshot, err := server.manager.Create(body.URL, body.AutoExtract)
+	snapshot, err := server.manager.Create(body)
 	if err != nil {
 		writeFailure(writer, err)
 		return

internal/server/server.go

@@ -45,7 +45,12 @@ func (server *Server) routes() http.Handler {
 	api.HandleFunc("GET /api/jobs/{id}/files", server.handleJobFiles)
 	api.HandleFunc("POST /api/jobs/{id}/extract", server.handleExtract)
 	api.HandleFunc("POST /api/jobs/{id}/move", server.handleMove)
+	api.HandleFunc("POST /api/jobs/{id}/pause", server.handlePause)
+	api.HandleFunc("POST /api/jobs/{id}/resume", server.handleResume)
+	api.HandleFunc("POST /api/jobs/{id}/queue", server.handleReorder)
 	api.HandleFunc("DELETE /api/jobs/{id}", server.handleDeleteJob)
+	api.HandleFunc("GET /api/history", server.handleHistory)
+	api.HandleFunc("DELETE /api/history", server.handleClearHistory)
 
 	root := http.NewServeMux()
 	root.HandleFunc("POST /api/login", server.handleLogin)

main.go

@@ -13,12 +13,16 @@ import (
 
 	"ddc/internal/auth"
 	"ddc/internal/config"
+	"ddc/internal/history"
 	"ddc/internal/jobs"
 	"ddc/internal/preferences"
 	"ddc/internal/server"
 )
 
-const settingsFileName = ".settings.json"
+const (
+	settingsFileName = ".settings.json"
+	historyFileName  = ".history.json"
+)
 
 func main() {
 	settings, err := config.Load()
@@ -43,7 +47,12 @@ func main() {
 		log.Fatalf("settings error: %v", err)
 	}
 
-	manager := jobs.NewManager(settings, store)
+	historyStore, err := history.Open(filepath.Join(settings.DownloadDir, historyFileName))
+	if err != nil {
+		log.Fatalf("history error: %v", err)
+	}
+
+	manager := jobs.NewManager(settings, store, historyStore)
 	if err := manager.RestoreExisting(); err != nil {
 		log.Printf("could not restore existing downloads: %v", err)
 	}
@@ -70,10 +79,9 @@ func main() {
 
 	<-shutdownSignal.Done()
 	log.Printf("shutting down")
-	manager.CancelAll()
-
 	shutdownContext, cancel := context.WithTimeout(context.Background(), 10*time.Second)
 	defer cancel()
+	manager.Shutdown(shutdownContext)
 	if err := httpServer.Shutdown(shutdownContext); err != nil {
 		log.Printf("shutdown error: %v", err)
 	}

web/static/icon.svg

@@ -0,0 +1,5 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 64 64">
+  <rect width="64" height="64" rx="14" fill="#3b6ef5"/>
+  <path d="M32 14v26M21 30l11 11 11-11" fill="none" stroke="#ffffff" stroke-width="6" stroke-linecap="round" stroke-linejoin="round"/>
+  <path d="M18 49h28" fill="none" stroke="#ffffff" stroke-width="6" stroke-linecap="round"/>
+</svg>

web/static/index.html

@@ -5,7 +5,7 @@
   <meta name="viewport" content="width=device-width, initial-scale=1, viewport-fit=cover">
   <meta name="theme-color" content="#16181d">
   <title>DDC</title>
-  <link rel="icon" href="data:,">
+  <link rel="icon" href="/icon.svg" type="image/svg+xml">
   <link rel="stylesheet" href="/style.css">
   <script src="/js/theme.js"></script>
   <script type="module" src="/js/app.js"></script>
@@ -46,9 +46,25 @@
       <section class="card">
         <h2>New download</h2>
         <form id="download-form" class="download-form">
-          <input id="download-url" type="url" inputmode="url" placeholder="https://example.com/file.zip" autocomplete="off" autocapitalize="off" required>
+          <textarea id="download-urls" rows="2" placeholder="https://example.com/file.zip (one link per line, Ctrl+Enter to start)" autocomplete="off" autocapitalize="off" spellcheck="false" required></textarea>
           <button type="submit" class="primary">Download</button>
         </form>
+        <div class="download-options">
+          <label class="field">
+            <span>File name (optional, single link)</span>
+            <input id="download-name" placeholder="Keep the server name" autocomplete="off" autocapitalize="off">
+          </label>
+          <label class="field">
+            <span>Download to</span>
+            <select id="download-destination">
+              <option value="">Temporary folder (move later)</option>
+            </select>
+          </label>
+          <label class="field">
+            <span>Subfolder (optional)</span>
+            <input id="download-subfolder" placeholder="Movie Name (2024)" autocomplete="off" disabled>
+          </label>
+        </div>
         <label class="checkbox">
           <input id="auto-extract" type="checkbox" checked>
           <span>Extract archives automatically</span>
@@ -57,7 +73,20 @@
       </section>
 
       <section class="card">
-        <h2>Downloads</h2>
+        <div class="list-toolbar">
+          <h2>Downloads</h2>
+          <div class="list-toolbar-actions">
+            <select id="job-filter" aria-label="Filter downloads">
+              <option value="all">All</option>
+              <option value="active">Active</option>
+              <option value="paused">Paused</option>
+              <option value="ready">Ready</option>
+              <option value="completed">Completed</option>
+              <option value="failed">Failed</option>
+            </select>
+            <button id="clear-completed-button" type="button" class="ghost small">Clear completed</button>
+          </div>
+        </div>
         <ul id="job-list" class="job-list"></ul>
         <p id="job-empty" class="empty-state">No downloads yet. Paste a link above to start.</p>
       </section>
@@ -86,6 +115,15 @@
         <button id="move-button" type="button" class="primary block-mobile" disabled>Move</button>
         <p id="action-error" class="error" role="alert"></p>
       </section>
+
+      <details id="history-card" class="card history-card">
+        <summary>
+          <span id="history-title">History</span>
+        </summary>
+        <ul id="history-list" class="history-list"></ul>
+        <p id="history-empty" class="empty-state">Moved files will be listed here.</p>
+        <button id="clear-history-button" type="button" class="ghost small">Clear history</button>
+      </details>
     </main>
   </div>
 
@@ -104,6 +142,10 @@
               <span>Parallel downloads</span>
               <input id="setting-concurrent" type="number" inputmode="numeric" min="1" max="10" required>
             </label>
+            <label class="field">
+              <span>Connections per download</span>
+              <input id="setting-connections" type="number" inputmode="numeric" min="1" max="16" required>
+            </label>
             <label class="field">
               <span>Keep free on disk (GB)</span>
               <input id="setting-min-free" type="number" inputmode="numeric" min="0" required>
@@ -127,6 +169,14 @@
           </label>
         </fieldset>
 
+        <fieldset class="settings-group">
+          <legend>Download paths</legend>
+          <label class="field">
+            <span>One folder per line, inside a destination root. Missing folders are created on first use.</span>
+            <textarea id="setting-download-paths" rows="4" placeholder="/media/blob/TeaNet/Plex/Movies/Kids" autocomplete="off" autocapitalize="off" spellcheck="false"></textarea>
+          </label>
+        </fieldset>
+
         <fieldset class="settings-group">
           <legend>Appearance</legend>
           <label class="field">
@@ -137,6 +187,10 @@
               <option value="dark">Dark</option>
             </select>
           </label>
+          <label class="checkbox">
+            <input id="setting-notifications" type="checkbox">
+            <span>Notify when downloads finish (this browser)</span>
+          </label>
         </fieldset>
 
         <fieldset class="settings-group">

web/static/js/api.js

@@ -53,9 +53,14 @@ export const api = {
   settings: () => request("GET", "/api/settings"),
   saveSettings: (settings) => request("POST", "/api/settings", settings),
   jobs: () => request("GET", "/api/jobs"),
-  createJob: (url, autoExtract) => request("POST", "/api/jobs", { url, autoExtract }),
+  createJob: (payload) => request("POST", "/api/jobs", payload),
   files: (id) => request("GET", jobPath(id, "/files")),
   extract: (id, path) => request("POST", jobPath(id, "/extract"), { path }),
   move: (id, payload) => request("POST", jobPath(id, "/move"), payload),
+  pause: (id) => request("POST", jobPath(id, "/pause"), {}),
+  resume: (id) => request("POST", jobPath(id, "/resume"), {}),
+  reorder: (id, direction) => request("POST", jobPath(id, "/queue"), { direction }),
   remove: (id) => request("DELETE", jobPath(id)),
+  history: () => request("GET", "/api/history"),
+  clearHistory: () => request("DELETE", "/api/history"),
 };

web/static/js/app.js

@@ -1,12 +1,17 @@
 import { api, onUnauthorized } from "./api.js";
 import { element } from "./dom.js";
+import { destinationSelect, setAutoExtractDefault, setupDownloadForm, updateSubfolderState } from "./download-form.js";
 import { formatBytes } from "./format.js";
-import { isActive, renderJobs, updateSpeeds } from "./jobs.js";
+import { recentDestinations, renderHistory } from "./history.js";
+import { isActive, matchesFilter, renderJobs, updateSpeeds } from "./jobs.js";
+import { fillLibrarySelect } from "./libraries.js";
 import { setupLogin } from "./login.js";
+import { collectTransitions, notifyTransitions } from "./notify.js";
 import { loadSettings, openSettings, setupSettings } from "./settings.js";
 import { renderTree, topLevelSelection } from "./tree.js";
 
 const pollIntervalMs = 1500;
+const filterStorageKey = "ddc-job-filter";
 
 const elements = {
   loginView: document.getElementById("login-view"),
@@ -16,10 +21,8 @@ const elements = {
   logoutButton: document.getElementById("logout-button"),
   settingsButton: document.getElementById("settings-button"),
   diskStatus: document.getElementById("disk-status"),
-  downloadForm: document.getElementById("download-form"),
-  downloadUrl: document.getElementById("download-url"),
-  autoExtract: document.getElementById("auto-extract"),
-  downloadError: document.getElementById("download-error"),
+  jobFilter: document.getElementById("job-filter"),
+  clearCompletedButton: document.getElementById("clear-completed-button"),
   jobList: document.getElementById("job-list"),
   jobEmpty: document.getElementById("job-empty"),
   detail: document.getElementById("job-detail"),
@@ -32,10 +35,19 @@ const elements = {
   cleanupCheckbox: document.getElementById("cleanup-checkbox"),
   moveButton: document.getElementById("move-button"),
   actionError: document.getElementById("action-error"),
+  history: {
+    title: document.getElementById("history-title"),
+    list: document.getElementById("history-list"),
+    empty: document.getElementById("history-empty"),
+    clearButton: document.getElementById("clear-history-button"),
+  },
 };
 
 const state = {
   jobs: [],
+  destinations: [],
+  downloadPaths: [],
+  historyEntries: [],
   selectedJobId: null,
   treeStatus: null,
   selection: new Set(),
@@ -54,14 +66,16 @@ async function showApp() {
   elements.loginView.hidden = true;
   elements.appView.hidden = false;
   applyDefaults(await loadSettings());
-  await loadLibraries();
+  await Promise.all([loadLibraries(), loadHistory()]);
   await refresh();
   startPolling();
 }
 
 function applyDefaults(settings) {
-  elements.autoExtract.checked = settings.autoExtract;
+  setAutoExtractDefault(settings.autoExtract);
   elements.cleanupCheckbox.checked = settings.cleanupAfterMove;
+  state.downloadPaths = settings.downloadPaths || [];
+  renderDestinationSelects();
 }
 
 async function showSettings() {
@@ -83,26 +97,25 @@ function stopPolling() {
 }
 
 async function loadLibraries() {
-  const destinations = (await api.libraries()) || [];
-  const previousValue = elements.librarySelect.value;
-  const groups = new Map();
+  state.destinations = (await api.libraries()) || [];
+  renderDestinationSelects();
+}
 
-  for (const destination of destinations) {
-    if (!groups.has(destination.root)) {
-      const group = document.createElement("optgroup");
-      group.label = destination.root;
-      groups.set(destination.root, group);
-    }
-    const option = element("option", "", destination.name);
-    option.value = destination.path;
-    option.title = destination.path;
-    groups.get(destination.root).append(option);
+async function loadHistory() {
+  try {
+    state.historyEntries = (await api.history()) || [];
+    renderHistory(elements.history, state.historyEntries);
+    renderDestinationSelects();
+  } catch (error) {
+    if (error.status !== 401) console.error(error);
   }
+}
 
-  elements.librarySelect.replaceChildren(...groups.values());
-  if (destinations.some((destination) => destination.path === previousValue)) {
-    elements.librarySelect.value = previousValue;
-  }
+function renderDestinationSelects() {
+  const extras = { recentPaths: recentDestinations(state.historyEntries), savedPaths: state.downloadPaths };
+  fillLibrarySelect(elements.librarySelect, state.destinations, extras);
+  fillLibrarySelect(destinationSelect(), state.destinations, { ...extras, emptyLabel: "Temporary folder (move later)" });
+  updateSubfolderState();
 }
 
 async function refresh() {
@@ -112,6 +125,7 @@ async function refresh() {
     const [jobs, disk] = await Promise.all([api.jobs(), api.disk()]);
     state.jobs = jobs || [];
     updateSpeeds(state.jobs);
+    handleTransitions(collectTransitions(state.jobs));
     elements.diskStatus.textContent = `${formatBytes(disk.availableBytes)} free`;
     renderJobList();
     await syncDetail();
@@ -122,14 +136,40 @@ async function refresh() {
   }
 }
 
+function handleTransitions(transitions) {
+  notifyTransitions(transitions);
+  if (transitions.some((transition) => transition.previous === "moving")) loadHistory();
+  if (transitions.length > 0) {
+    loadLibraries().catch((error) => console.error(error));
+  }
+}
+
 function renderJobList() {
-  elements.jobEmpty.hidden = state.jobs.length > 0;
-  renderJobs(elements.jobList, state.jobs, state.selectedJobId, {
+  const filter = elements.jobFilter.value;
+  const visibleJobs = state.jobs.filter((job) => matchesFilter(job, filter));
+  elements.jobEmpty.hidden = visibleJobs.length > 0;
+  elements.jobEmpty.textContent = state.jobs.length === 0
+    ? "No downloads yet. Paste a link above to start."
+    : "No downloads match this filter.";
+  elements.clearCompletedButton.hidden = !state.jobs.some((job) => job.status === "completed");
+  renderJobs(elements.jobList, visibleJobs, state.selectedJobId, {
     onBrowse: openDetail,
+    onPause: (job) => runJobAction(() => api.pause(job.id)),
+    onResume: (job) => runJobAction(() => api.resume(job.id)),
+    onReorder: (job, direction) => runJobAction(() => api.reorder(job.id, direction)),
     onDelete: deleteJob,
   });
 }
 
+async function runJobAction(action) {
+  try {
+    await action();
+    await refresh();
+  } catch (error) {
+    window.alert(error.message);
+  }
+}
+
 function selectedJob() {
   return state.jobs.find((job) => job.id === state.selectedJobId);
 }
@@ -201,18 +241,6 @@ function updateSelectionSummary() {
   elements.moveButton.disabled = count === 0 || !job || job.status !== "ready";
 }
 
-async function submitDownload(event) {
-  event.preventDefault();
-  elements.downloadError.textContent = "";
-  try {
-    await api.createJob(elements.downloadUrl.value.trim(), elements.autoExtract.checked);
-    elements.downloadUrl.value = "";
-    await refresh();
-  } catch (error) {
-    elements.downloadError.textContent = error.message;
-  }
-}
-
 async function extractArchive(path) {
   elements.actionError.textContent = "";
   try {
@@ -257,6 +285,48 @@ async function deleteJob(job) {
   }
 }
 
+async function clearCompleted() {
+  const completedJobs = state.jobs.filter((job) => job.status === "completed");
+  for (const job of completedJobs) {
+    try {
+      await api.remove(job.id);
+      if (job.id === state.selectedJobId) closeDetail();
+    } catch (error) {
+      console.error(error);
+    }
+  }
+  await refresh();
+}
+
+async function clearHistory() {
+  if (!window.confirm("Clear the move history?")) return;
+  try {
+    await api.clearHistory();
+    await loadHistory();
+  } catch (error) {
+    window.alert(error.message);
+  }
+}
+
+function setupJobFilter() {
+  try {
+    const saved = localStorage.getItem(filterStorageKey);
+    if (saved && [...elements.jobFilter.options].some((option) => option.value === saved)) {
+      elements.jobFilter.value = saved;
+    }
+  } catch {
+    elements.jobFilter.value = "all";
+  }
+  elements.jobFilter.addEventListener("change", () => {
+    try {
+      localStorage.setItem(filterStorageKey, elements.jobFilter.value);
+    } catch {
+      console.warn("Could not remember the download filter.");
+    }
+    renderJobList();
+  });
+}
+
 async function logout() {
   try {
     await api.logout();
@@ -268,7 +338,10 @@ async function logout() {
 async function init() {
   onUnauthorized(showLogin);
   setupLogin(elements.loginForm, elements.loginError, showApp);
-  elements.downloadForm.addEventListener("submit", submitDownload);
+  setupDownloadForm(refresh);
+  setupJobFilter();
+  elements.clearCompletedButton.addEventListener("click", clearCompleted);
+  elements.history.clearButton.addEventListener("click", clearHistory);
   elements.moveButton.addEventListener("click", moveSelection);
   elements.closeDetailButton.addEventListener("click", () => {
     closeDetail();

web/static/js/download-form.js

@@ -0,0 +1,77 @@
+import { api } from "./api.js";
+
+const fields = {
+  form: document.getElementById("download-form"),
+  urls: document.getElementById("download-urls"),
+  name: document.getElementById("download-name"),
+  autoExtract: document.getElementById("auto-extract"),
+  destination: document.getElementById("download-destination"),
+  subfolder: document.getElementById("download-subfolder"),
+  error: document.getElementById("download-error"),
+};
+
+export function setupDownloadForm(onCreated) {
+  fields.form.addEventListener("submit", (event) => submitDownloads(event, onCreated));
+  fields.urls.addEventListener("keydown", (event) => {
+    if (event.key === "Enter" && (event.ctrlKey || event.metaKey)) {
+      event.preventDefault();
+      fields.form.requestSubmit();
+    }
+  });
+  fields.destination.addEventListener("change", updateSubfolderState);
+}
+
+export function setAutoExtractDefault(enabled) {
+  fields.autoExtract.checked = enabled;
+}
+
+export function destinationSelect() {
+  return fields.destination;
+}
+
+export function updateSubfolderState() {
+  fields.subfolder.disabled = fields.destination.value === "";
+}
+
+async function submitDownloads(event, onCreated) {
+  event.preventDefault();
+  fields.error.textContent = "";
+
+  const urls = fields.urls.value.split("\n").map((line) => line.trim()).filter(Boolean);
+  const fileName = fields.name.value.trim();
+  if (urls.length === 0) {
+    fields.error.textContent = "Paste at least one link.";
+    return;
+  }
+  if (fileName && urls.length > 1) {
+    fields.error.textContent = "A file name can only be set when downloading a single link.";
+    return;
+  }
+
+  const failedUrls = [];
+  let firstError = "";
+  for (const url of urls) {
+    try {
+      await api.createJob({
+        url,
+        fileName,
+        autoExtract: fields.autoExtract.checked,
+        destination: fields.destination.value,
+        subfolder: fields.subfolder.value.trim(),
+      });
+    } catch (error) {
+      failedUrls.push(url);
+      if (!firstError) firstError = error.message;
+    }
+  }
+
+  fields.urls.value = failedUrls.join("\n");
+  if (failedUrls.length === 0) {
+    fields.name.value = "";
+    fields.subfolder.value = "";
+  } else {
+    const prefix = urls.length > 1 ? `${failedUrls.length} of ${urls.length} links failed: ` : "";
+    fields.error.textContent = prefix + firstError;
+  }
+  await onCreated();
+}

web/static/js/format.js

@@ -3,6 +3,7 @@ const units = ["B", "KB", "MB", "GB", "TB"];
 export const statusLabels = {
   queued: "Queued",
   downloading: "Downloading",
+  paused: "Paused",
   extracting: "Extracting",
   ready: "Ready",
   moving: "Moving",
@@ -21,6 +22,21 @@ export function formatBytes(bytes) {
   return `${value.toFixed(unitIndex === 0 ? 0 : 1)} ${units[unitIndex]}`;
 }
 
+export function formatDuration(seconds) {
+  const total = Math.max(0, Math.round(seconds));
+  const hours = Math.floor(total / 3600);
+  const minutes = Math.floor((total % 3600) / 60);
+  const remainingSeconds = total % 60;
+  if (hours > 0) return `${hours}h ${minutes}m`;
+  if (minutes > 0) return `${minutes}m ${remainingSeconds}s`;
+  return `${remainingSeconds}s`;
+}
+
+export function formatDate(value) {
+  const date = new Date(value);
+  return Number.isNaN(date.getTime()) ? "" : date.toLocaleString();
+}
+
 export function percentOf(done, total) {
   if (!total || total <= 0) return null;
   return Math.min(100, (done / total) * 100);

web/static/js/history.js

@@ -0,0 +1,33 @@
+import { element } from "./dom.js";
+import { formatDate } from "./format.js";
+
+const maxRecentPaths = 5;
+
+export function recentDestinations(entries) {
+  const paths = [];
+  for (const entry of entries) {
+    if (!paths.includes(entry.destination)) paths.push(entry.destination);
+    if (paths.length >= maxRecentPaths) break;
+  }
+  return paths;
+}
+
+export function renderHistory(elements, entries) {
+  elements.title.textContent = entries.length > 0 ? `History (${entries.length})` : "History";
+  elements.empty.hidden = entries.length > 0;
+  elements.clearButton.hidden = entries.length === 0;
+  elements.list.replaceChildren(...entries.map(renderEntry));
+}
+
+function renderEntry(entry) {
+  const item = element("li", "history-item");
+  const items = entry.items || [];
+  const itemText = items.length === 1 ? items[0] : `${items.length} items`;
+  item.append(
+    element("div", "history-name", entry.fileName || itemText),
+    element("p", "history-meta muted", `${itemText} moved to ${entry.destination}`),
+    element("p", "history-meta muted", formatDate(entry.movedAt)),
+  );
+  if (entry.sourceUrl) item.append(element("p", "history-meta muted", entry.sourceUrl));
+  return item;
+}

web/static/js/jobs.js

@@ -1,13 +1,21 @@
 import { button, element } from "./dom.js";
-import { formatBytes, percentOf, statusLabels } from "./format.js";
+import { formatBytes, formatDuration, percentOf, statusLabels } from "./format.js";
 
 const activeStatuses = new Set(["queued", "downloading", "extracting", "moving"]);
+const pausableStatuses = new Set(["queued", "downloading"]);
+const speedSmoothing = 0.3;
 const speedSamples = new Map();
 
 export function isActive(job) {
   return activeStatuses.has(job.status);
 }
 
+export function matchesFilter(job, filter) {
+  if (filter === "all") return true;
+  if (filter === "active") return isActive(job);
+  return job.status === filter;
+}
+
 export function updateSpeeds(jobs) {
   const now = performance.now();
   const seenIds = new Set();
@@ -17,7 +25,8 @@ export function updateSpeeds(jobs) {
     const previous = speedSamples.get(job.id);
     let speed = 0;
     if (previous && job.bytesDone >= previous.bytes && now > previous.time) {
-      speed = ((job.bytesDone - previous.bytes) * 1000) / (now - previous.time);
+      const instantSpeed = ((job.bytesDone - previous.bytes) * 1000) / (now - previous.time);
+      speed = previous.speed > 0 ? previous.speed + speedSmoothing * (instantSpeed - previous.speed) : instantSpeed;
     }
     speedSamples.set(job.id, { bytes: job.bytesDone, time: now, speed });
   }
@@ -27,8 +36,25 @@ export function updateSpeeds(jobs) {
   }
 }
 
+function displayRank(job) {
+  if (isActive(job) && !job.queuePosition) return 0;
+  if (job.queuePosition) return 1;
+  return 2;
+}
+
+function sortForDisplay(jobs) {
+  return [...jobs].sort((first, second) => {
+    const rankDifference = displayRank(first) - displayRank(second);
+    if (rankDifference !== 0) return rankDifference;
+    if (first.queuePosition && second.queuePosition) return first.queuePosition - second.queuePosition;
+    return 0;
+  });
+}
+
 export function renderJobs(container, jobs, selectedId, handlers) {
-  container.replaceChildren(...jobs.map((job) => renderJob(job, job.id === selectedId, handlers)));
+  const queueLength = jobs.filter((job) => job.queuePosition).length;
+  const context = { ...handlers, queueLength };
+  container.replaceChildren(...sortForDisplay(jobs).map((job) => renderJob(job, job.id === selectedId, context)));
 }
 
 function renderJob(job, selected, handlers) {
@@ -42,6 +68,12 @@ function renderJob(job, selected, handlers) {
   item.append(header);
 
   if (job.sourceUrl) item.append(element("p", "job-source muted", job.sourceUrl));
+  if (job.moveTarget && job.status !== "completed") {
+    item.append(element("p", "job-source muted", `Download to: ${job.moveTarget}`));
+  }
+  if (job.queuePosition) {
+    item.append(element("p", "job-source muted", `Queue position ${job.queuePosition} of ${handlers.queueLength}`));
+  }
   if (job.status !== "completed") item.append(renderProgress(job));
   if (job.message) {
     const messageClass = job.status === "failed" ? "job-message error" : "job-message muted";
@@ -79,7 +111,12 @@ function progressText(job, percent) {
   if (percent !== null) parts.push(`${percent.toFixed(1)}%`);
 
   const sample = speedSamples.get(job.id);
-  if (isActive(job) && sample && sample.speed > 0) parts.push(`${formatBytes(sample.speed)}/s`);
+  if (isActive(job) && sample && sample.speed > 0) {
+    parts.push(`${formatBytes(sample.speed)}/s`);
+    if (job.bytesTotal > job.bytesDone) {
+      parts.push(`${formatDuration((job.bytesTotal - job.bytesDone) / sample.speed)} left`);
+    }
+  }
   return parts.join("  |  ");
 }
 
@@ -88,6 +125,20 @@ function renderActions(job, handlers) {
   if (job.status === "ready") {
     actions.append(button("Browse files", "secondary small", () => handlers.onBrowse(job)));
   }
+  if (job.queuePosition > 1) {
+    actions.append(button("Start next", "secondary small", () => handlers.onReorder(job, "first")));
+    actions.append(button("Move up", "secondary small", () => handlers.onReorder(job, "up")));
+  }
+  if (job.queuePosition && job.queuePosition < handlers.queueLength) {
+    actions.append(button("Move down", "secondary small", () => handlers.onReorder(job, "down")));
+  }
+  if (pausableStatuses.has(job.status)) {
+    actions.append(button("Pause", "secondary small", () => handlers.onPause(job)));
+  }
+  if (job.status === "paused" || job.status === "failed") {
+    const label = job.status === "paused" ? "Resume" : "Retry";
+    actions.append(button(label, "secondary small", () => handlers.onResume(job)));
+  }
   if (job.status !== "moving") {
     actions.append(button(isActive(job) ? "Cancel" : "Remove", "danger small", () => handlers.onDelete(job)));
   }

web/static/js/libraries.js

@@ -0,0 +1,61 @@
+import { element } from "./dom.js";
+import { formatBytes } from "./format.js";
+
+function withFreeSpace(label, destination) {
+  if (!destination || destination.freeBytes < 0) return label;
+  return `${label} - ${formatBytes(destination.freeBytes)} free`;
+}
+
+function destinationForPath(destinations, path) {
+  return destinations.find((destination) => path === destination.path || path.startsWith(`${destination.path}/`));
+}
+
+function libraryGroups(destinations) {
+  const groups = new Map();
+  for (const destination of destinations) {
+    if (!groups.has(destination.root)) {
+      const group = document.createElement("optgroup");
+      group.label = destination.root;
+      groups.set(destination.root, group);
+    }
+    const option = element("option", "", withFreeSpace(destination.name, destination));
+    option.value = destination.path;
+    option.title = destination.path;
+    groups.get(destination.root).append(option);
+  }
+  return [...groups.values()];
+}
+
+function pathGroup(label, paths, destinations) {
+  const group = document.createElement("optgroup");
+  group.label = label;
+  for (const path of paths) {
+    const option = element("option", "", withFreeSpace(path, destinationForPath(destinations, path)));
+    option.value = path;
+    option.title = path;
+    group.append(option);
+  }
+  return group;
+}
+
+export function fillLibrarySelect(select, destinations, extras = {}) {
+  const previousValue = select.value;
+  const leadingOptions = [];
+  if (extras.emptyLabel) {
+    const emptyOption = element("option", "", extras.emptyLabel);
+    emptyOption.value = "";
+    leadingOptions.push(emptyOption);
+  }
+  if (extras.recentPaths && extras.recentPaths.length > 0) {
+    leadingOptions.push(pathGroup("Recent", extras.recentPaths, destinations));
+  }
+  if (extras.savedPaths && extras.savedPaths.length > 0) {
+    leadingOptions.push(pathGroup("Saved paths", extras.savedPaths, destinations));
+  }
+
+  select.replaceChildren(...leadingOptions, ...libraryGroups(destinations));
+  const availableValues = [...select.options].map((option) => option.value);
+  if (availableValues.includes(previousValue)) {
+    select.value = previousValue;
+  }
+}

web/static/js/notify.js

@@ -0,0 +1,68 @@
+const storageKey = "ddc-notifications";
+const finishedTitles = {
+  ready: "Download ready",
+  completed: "Download moved",
+  failed: "Download failed",
+};
+const previousStatuses = new Map();
+
+function notificationsSupported() {
+  return "Notification" in window;
+}
+
+function readPreference() {
+  try {
+    return localStorage.getItem(storageKey) === "on";
+  } catch {
+    return false;
+  }
+}
+
+function storePreference(enabled) {
+  try {
+    localStorage.setItem(storageKey, enabled ? "on" : "off");
+  } catch {
+    return;
+  }
+}
+
+export function notificationsEnabled() {
+  return notificationsSupported() && Notification.permission === "granted" && readPreference();
+}
+
+export async function setNotificationsEnabled(enabled) {
+  if (!enabled) {
+    storePreference(false);
+    return;
+  }
+  if (!notificationsSupported()) throw new Error("This browser does not support notifications.");
+  const permission = await Notification.requestPermission();
+  if (permission !== "granted") throw new Error("Notifications are blocked for this site in the browser settings.");
+  storePreference(true);
+}
+
+export function collectTransitions(jobs) {
+  const transitions = [];
+  const seenIds = new Set();
+  for (const job of jobs) {
+    seenIds.add(job.id);
+    const previous = previousStatuses.get(job.id);
+    if (previous && previous !== job.status) transitions.push({ job, previous });
+    previousStatuses.set(job.id, job.status);
+  }
+  for (const id of previousStatuses.keys()) {
+    if (!seenIds.has(id)) previousStatuses.delete(id);
+  }
+  return transitions;
+}
+
+export function notifyTransitions(transitions) {
+  if (!notificationsEnabled()) return;
+  for (const { job, previous } of transitions) {
+    const title = finishedTitles[job.status];
+    const wasWorking = previous === "queued" || previous === "downloading" || previous === "extracting" || previous === "moving";
+    if (!title || !wasWorking) continue;
+    if (job.status === "ready" && previous === "moving") continue;
+    new Notification(title, { body: job.fileName || job.sourceUrl, tag: `ddc-${job.id}` });
+  }
+}

web/static/js/settings.js

@@ -1,5 +1,6 @@
 import { api } from "./api.js";
 import { element } from "./dom.js";
+import { notificationsEnabled, setNotificationsEnabled } from "./notify.js";
 
 const themeStorageKey = "ddc-theme";
 
@@ -10,10 +11,13 @@ const fields = {
   cancelButton: document.getElementById("settings-cancel"),
   error: document.getElementById("settings-error"),
   concurrent: document.getElementById("setting-concurrent"),
+  connections: document.getElementById("setting-connections"),
+  notifications: document.getElementById("setting-notifications"),
   minFree: document.getElementById("setting-min-free"),
   ports: document.getElementById("setting-ports"),
   autoExtract: document.getElementById("setting-auto-extract"),
   cleanup: document.getElementById("setting-cleanup"),
+  downloadPaths: document.getElementById("setting-download-paths"),
   theme: document.getElementById("setting-theme"),
   downloadDir: document.getElementById("info-download-dir"),
   roots: document.getElementById("info-roots"),
@@ -42,10 +46,13 @@ export async function openSettings() {
 function fillForm(data) {
   const settings = data.settings;
   fields.concurrent.value = settings.maxConcurrentDownloads;
+  fields.connections.value = settings.connectionsPerDownload;
+  fields.notifications.checked = notificationsEnabled();
   fields.minFree.value = settings.minFreeGB;
   fields.ports.value = settings.allowedPorts.length > 0 ? settings.allowedPorts.join(", ") : "*";
   fields.autoExtract.checked = settings.autoExtract;
   fields.cleanup.checked = settings.cleanupAfterMove;
+  fields.downloadPaths.value = (settings.downloadPaths || []).join("\n");
   fields.theme.value = readTheme();
   fields.downloadDir.textContent = data.downloadDir;
   fields.roots.replaceChildren(...data.libraryRoots.map((root) => element("div", "mono", root)));
@@ -57,11 +64,14 @@ async function saveSettings(event, onSaved) {
   try {
     const payload = {
       maxConcurrentDownloads: Number(fields.concurrent.value),
+      connectionsPerDownload: Number(fields.connections.value),
       minFreeGB: Number(fields.minFree.value),
       allowedPorts: parsePorts(fields.ports.value),
       autoExtract: fields.autoExtract.checked,
       cleanupAfterMove: fields.cleanup.checked,
+      downloadPaths: parseDownloadPaths(fields.downloadPaths.value),
     };
+    await setNotificationsEnabled(fields.notifications.checked);
     const data = await api.saveSettings(payload);
     storeTheme(fields.theme.value);
     fields.dialog.close();
@@ -80,6 +90,10 @@ function parsePorts(text) {
   return ports;
 }
 
+function parseDownloadPaths(text) {
+  return text.split("\n").map((line) => line.trim()).filter(Boolean);
+}
+
 function readTheme() {
   try {
     return localStorage.getItem(themeStorageKey) || "system";

web/static/style.css

@@ -97,13 +97,15 @@ h2 {
 
 input,
 select,
+textarea,
 button {
   font: inherit;
   color: inherit;
 }
 
 input:not([type="checkbox"]),
-select {
+select,
+textarea {
   width: 100%;
   min-height: 42px;
   padding: 9px 12px;
@@ -113,8 +115,13 @@ select {
   transition: border-color 0.15s ease, box-shadow 0.15s ease;
 }
 
+textarea {
+  resize: vertical;
+}
+
 input:not([type="checkbox"]):focus,
-select:focus {
+select:focus,
+textarea:focus {
   outline: none;
   border-color: var(--accent);
   box-shadow: 0 0 0 3px var(--accent-soft);
@@ -724,3 +731,102 @@ button.block {
     display: none;
   }
 }
+
+.badge-paused {
+  color: var(--muted);
+  background: var(--border);
+}
+
+.download-form {
+  align-items: flex-start;
+}
+
+.download-form textarea {
+  flex: 1 1 auto;
+  min-height: 64px;
+}
+
+.download-options {
+  display: grid;
+  grid-template-columns: repeat(3, 1fr);
+  gap: 12px;
+  margin-top: 14px;
+}
+
+.list-toolbar {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  flex-wrap: wrap;
+  gap: 10px;
+  margin-bottom: 14px;
+}
+
+.list-toolbar h2 {
+  margin: 0;
+}
+
+.list-toolbar-actions {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.list-toolbar-actions select {
+  width: auto;
+  min-height: 36px;
+  padding: 6px 10px;
+}
+
+.history-card summary {
+  cursor: pointer;
+  font-size: 1.05rem;
+  font-weight: 650;
+}
+
+.history-list {
+  list-style: none;
+  padding: 0;
+  margin: 14px 0 12px;
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+  max-height: 420px;
+  overflow-y: auto;
+}
+
+.history-list:empty {
+  display: none;
+}
+
+.history-item {
+  border: 1px solid var(--border);
+  border-radius: var(--radius-small);
+  padding: 10px 12px;
+  background: var(--surface-alt);
+}
+
+.history-name {
+  font-weight: 600;
+  overflow-wrap: anywhere;
+}
+
+.history-meta {
+  font-size: 0.8rem;
+  margin: 4px 0 0;
+  overflow-wrap: anywhere;
+}
+
+.history-card .empty-state {
+  margin: 14px 0 12px;
+}
+
+@media (max-width: 640px) {
+  .download-form textarea {
+    width: 100%;
+  }
+
+  .download-options {
+    grid-template-columns: 1fr;
+  }
+}