v6.6

backend/cover.go

@@ -0,0 +1,176 @@
+package backend
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+const (
+	// Spotify image size codes
+	spotifySize640 = "ab67616d0000b273" // 640x640
+	spotifySizeMax = "ab67616d000082c1" // Max resolution
+)
+
+// CoverDownloadRequest represents a request to download cover art
+type CoverDownloadRequest struct {
+	CoverURL       string `json:"cover_url"`
+	TrackName      string `json:"track_name"`
+	ArtistName     string `json:"artist_name"`
+	OutputDir      string `json:"output_dir"`
+	FilenameFormat string `json:"filename_format"`
+	TrackNumber    bool   `json:"track_number"`
+	Position       int    `json:"position"`
+}
+
+// CoverDownloadResponse represents the response from cover download
+type CoverDownloadResponse struct {
+	Success       bool   `json:"success"`
+	Message       string `json:"message"`
+	File          string `json:"file,omitempty"`
+	Error         string `json:"error,omitempty"`
+	AlreadyExists bool   `json:"already_exists,omitempty"`
+}
+
+// CoverClient handles cover art downloading
+type CoverClient struct {
+	httpClient *http.Client
+}
+
+// NewCoverClient creates a new cover client
+func NewCoverClient() *CoverClient {
+	return &CoverClient{
+		httpClient: &http.Client{Timeout: 30 * time.Second},
+	}
+}
+
+// buildCoverFilename builds the cover filename based on settings (same as track filename)
+func buildCoverFilename(trackName, artistName, filenameFormat string, includeTrackNumber bool, position int) string {
+	safeTitle := sanitizeFilename(trackName)
+	safeArtist := sanitizeFilename(artistName)
+
+	var filename string
+
+	// Build base filename based on format
+	switch filenameFormat {
+	case "artist-title":
+		filename = fmt.Sprintf("%s - %s", safeArtist, safeTitle)
+	case "title":
+		filename = safeTitle
+	default: // "title-artist"
+		filename = fmt.Sprintf("%s - %s", safeTitle, safeArtist)
+	}
+
+	// Add track number prefix if enabled
+	if includeTrackNumber && position > 0 {
+		filename = fmt.Sprintf("%02d. %s", position, filename)
+	}
+
+	return filename + ".jpg"
+}
+
+// getMaxResolutionURL converts a Spotify cover URL to max resolution
+// Falls back to original URL if max resolution is not available
+func (c *CoverClient) getMaxResolutionURL(coverURL string) string {
+	// Try to convert to max resolution
+	if strings.Contains(coverURL, spotifySize640) {
+		maxURL := strings.Replace(coverURL, spotifySize640, spotifySizeMax, 1)
+		// Check if max resolution URL is available
+		resp, err := c.httpClient.Head(maxURL)
+		if err == nil && resp.StatusCode == http.StatusOK {
+			return maxURL
+		}
+	}
+	// Return original URL as fallback
+	return coverURL
+}
+
+// DownloadCover downloads cover art for a single track
+func (c *CoverClient) DownloadCover(req CoverDownloadRequest) (*CoverDownloadResponse, error) {
+	if req.CoverURL == "" {
+		return &CoverDownloadResponse{
+			Success: false,
+			Error:   "Cover URL is required",
+		}, fmt.Errorf("cover URL is required")
+	}
+
+	// Create output directory if it doesn't exist
+	outputDir := req.OutputDir
+	if outputDir == "" {
+		outputDir = GetDefaultMusicPath()
+	}
+
+	if err := os.MkdirAll(outputDir, 0755); err != nil {
+		return &CoverDownloadResponse{
+			Success: false,
+			Error:   fmt.Sprintf("failed to create output directory: %v", err),
+		}, err
+	}
+
+	// Generate filename using same format as track
+	filenameFormat := req.FilenameFormat
+	if filenameFormat == "" {
+		filenameFormat = "title-artist" // default
+	}
+	filename := buildCoverFilename(req.TrackName, req.ArtistName, filenameFormat, req.TrackNumber, req.Position)
+	filePath := filepath.Join(outputDir, filename)
+
+	// Check if file already exists
+	if fileInfo, err := os.Stat(filePath); err == nil && fileInfo.Size() > 0 {
+		return &CoverDownloadResponse{
+			Success:       true,
+			Message:       "Cover file already exists",
+			File:          filePath,
+			AlreadyExists: true,
+		}, nil
+	}
+
+	// Try to get max resolution URL, fallback to original
+	downloadURL := c.getMaxResolutionURL(req.CoverURL)
+
+	// Download cover image
+	resp, err := c.httpClient.Get(downloadURL)
+	if err != nil {
+		return &CoverDownloadResponse{
+			Success: false,
+			Error:   fmt.Sprintf("failed to download cover: %v", err),
+		}, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return &CoverDownloadResponse{
+			Success: false,
+			Error:   fmt.Sprintf("failed to download cover: HTTP %d", resp.StatusCode),
+		}, fmt.Errorf("HTTP %d", resp.StatusCode)
+	}
+
+	// Create file
+	file, err := os.Create(filePath)
+	if err != nil {
+		return &CoverDownloadResponse{
+			Success: false,
+			Error:   fmt.Sprintf("failed to create file: %v", err),
+		}, err
+	}
+	defer file.Close()
+
+	// Write content to file
+	_, err = io.Copy(file, resp.Body)
+	if err != nil {
+		return &CoverDownloadResponse{
+			Success: false,
+			Error:   fmt.Sprintf("failed to write cover file: %v", err),
+		}, err
+	}
+
+	return &CoverDownloadResponse{
+		Success: true,
+		Message: "Cover downloaded successfully",
+		File:    filePath,
+	}, nil
+}