Add resumable downloads, download paths, queue controls and history

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}
+	}
+}