Add resumable downloads, download paths, queue controls and history

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
 }