fix: resolve bugs found in pre-release review

internal/download/bpm.go

@@ -93,7 +93,7 @@ func findTrackURL(ctx context.Context, httpClient *http.Client, artist, title, d
 
 		const toleranceSec = 2
 		foundDuration := minutes*60 + seconds
-		if foundDuration <= wantDuration-toleranceSec || foundDuration >= wantDuration+toleranceSec {
+		if foundDuration < wantDuration-toleranceSec || foundDuration > wantDuration+toleranceSec {
 			return true
 		}
 

internal/download/download.go

@@ -81,6 +81,7 @@ func (d *Downloader) prepareResource(ctx context.Context, id string, opts Option
 	if err := fsutil.EnsureDir(outputDir); err != nil {
 		return nil, "", fmt.Errorf("failed to create output directory: %w", err)
 	}
+	sweepPartFiles(outputDir)
 
 	return resource, outputDir, nil
 }

internal/download/genre.go

@@ -4,7 +4,10 @@ import (
 	"context"
 	"fmt"
 	"net/http"
+	"net/url"
 	"strings"
+	"unicode"
+	"unicode/utf8"
 
 	"github.com/PuerkitoBio/goquery"
 )
@@ -31,7 +34,9 @@ func toLower(ss []string) []string {
 }
 
 func fetchGenre(ctx context.Context, httpClient *http.Client, artist, title string) (string, error) {
-	reqURL := fmt.Sprintf("https://www.last.fm/music/%s/%s/+tags", artist, title)
+	// Escape the path segments: names containing '/', '?', or '#' would
+	// otherwise change the URL structure and fetch the wrong page.
+	reqURL := fmt.Sprintf("https://www.last.fm/music/%s/%s/+tags", url.PathEscape(artist), url.PathEscape(title))
 
 	doc, err := fetchGenrePage(ctx, httpClient, reqURL)
 	if err != nil {
@@ -116,7 +121,8 @@ func formatTags(tags []string) string {
 		}
 		words := strings.Fields(tag)
 		for i, w := range words {
-			words[i] = strings.ToUpper(w[:1]) + strings.ToLower(w[1:])
+			r, size := utf8.DecodeRuneInString(w)
+			words[i] = string(unicode.ToUpper(r)) + strings.ToLower(w[size:])
 		}
 		formatted = append(formatted, strings.Join(words, " "))
 	}

internal/download/stream.go

@@ -5,20 +5,41 @@ import (
 	"errors"
 	"io"
 	"os"
+	"path/filepath"
 
 	"github.com/mathismqn/godeez/internal/deezer"
 )
 
-const chunkSize = 2048
+const (
+	chunkSize   = 2048
+	partPattern = ".godeez-*.part"
+)
+
+func sweepPartFiles(dir string) {
+	matches, err := filepath.Glob(filepath.Join(dir, partPattern))
+	if err != nil {
+		return
+	}
+	for _, match := range matches {
+		os.Remove(match)
+	}
+}
 
 func (d *Downloader) streamToFile(ctx context.Context, stream io.ReadCloser, outputPath string, key []byte) error {
 	defer stream.Close()
 
-	file, err := os.Create(outputPath)
+	file, err := os.CreateTemp(filepath.Dir(outputPath), partPattern)
 	if err != nil {
 		return err
 	}
-	defer file.Close()
+	tmpPath := file.Name()
+	done := false
+	defer func() {
+		if !done {
+			file.Close()
+			os.Remove(tmpPath)
+		}
+	}()
 
 	buffer := make([]byte, chunkSize)
 	for chunk := 0; ; chunk++ {
@@ -60,5 +81,16 @@ func (d *Downloader) streamToFile(ctx context.Context, stream io.ReadCloser, out
 		}
 	}
 
+	if err := file.Sync(); err != nil {
+		return err
+	}
+	if err := file.Close(); err != nil {
+		return err
+	}
+	if err := os.Rename(tmpPath, outputPath); err != nil {
+		return err
+	}
+	done = true
+
 	return nil
 }

internal/download/track.go

@@ -34,20 +34,19 @@ func (d *Downloader) downloadTrack(ctx context.Context, resource deezer.Resource
 		metadataChan <- fetchMetadata(d.deezerClient.Session.HTTPClient, ctx, track, opts)
 	}()
 
-	stream, err := d.deezerClient.MediaStream(ctx, media)
+	dlCtx, cancel := context.WithTimeout(ctx, opts.Timeout)
+	defer cancel()
+
+	stream, err := d.deezerClient.MediaStream(dlCtx, media)
 	if err != nil {
 		return downloadResult{err: fmt.Errorf("failed to get media stream: %w", err)}
 	}
 
-	dlCtx, cancel := context.WithTimeout(ctx, opts.Timeout)
-	defer cancel()
-
 	fileName := track.Filename(d.kind, mediaFormat)
-	outputPath := filepath.Join(outputDir, fileName)
+	outputPath := d.uniqueOutputPath(track.ID, filepath.Join(outputDir, fileName))
 
 	key := deezer.BlowfishKey(track.ID)
 	if err := d.streamToFile(dlCtx, stream, outputPath, key); err != nil {
-		fsutil.Remove(outputPath)
 		return downloadResult{err: fmt.Errorf("failed to stream to file: %w", err)}
 	}
 
@@ -63,12 +62,34 @@ func (d *Downloader) downloadTrack(ctx context.Context, resource deezer.Resource
 	}
 
 	metadata := <-metadataChan
+
+	if err := ctx.Err(); err != nil {
+		fsutil.Remove(outputPath)
+		return downloadResult{err: err}
+	}
+
 	warnings = append(warnings, metadata.warnings...)
 	warnings = append(warnings, d.finalizeDownload(resource, track, outputPath, mediaFormat, metadata.genre, cover, metadata.bpmKey)...)
 
 	return downloadResult{warnings: warnings}
 }
 
+func (d *Downloader) uniqueOutputPath(trackID, path string) string {
+	owned := ""
+	if info, err := d.store.DownloadInfo(trackID); err == nil {
+		owned = info.Path
+	}
+
+	ext := filepath.Ext(path)
+	stem := strings.TrimSuffix(path, ext)
+	candidate := path
+	for i := 2; candidate != owned && fsutil.Exists(candidate); i++ {
+		candidate = fmt.Sprintf("%s (%d)%s", stem, i, ext)
+	}
+
+	return candidate
+}
+
 func (d *Downloader) finalizeDownload(resource deezer.Resource, track *deezer.Track, outputPath, mediaFormat, genre string, cover []byte, bpmKey bpmKey) []string {
 	var warnings []string