refactor: move BPM fetching logic into provider package

internal/downloader/client.go

@@ -12,12 +12,12 @@ import (
 	"time"
 
 	"github.com/briandowns/spinner"
-	"github.com/mathismqn/godeez/internal/bpm"
 	"github.com/mathismqn/godeez/internal/config"
 	"github.com/mathismqn/godeez/internal/crypto"
 	"github.com/mathismqn/godeez/internal/deezer"
 	"github.com/mathismqn/godeez/internal/fileutil"
 	"github.com/mathismqn/godeez/internal/logger"
+	"github.com/mathismqn/godeez/internal/provider"
 	"github.com/mathismqn/godeez/internal/store"
 	"github.com/mathismqn/godeez/internal/tags"
 )
@@ -192,19 +192,20 @@ func (c *Client) downloadSong(ctx context.Context, resource deezer.Resource, son
 		return nil, SkipError{Path: path}
 	}
 
-	var metricsChan chan *bpm.Metrics
+	var bpmChan chan provider.BPMKey
 	var errChan chan error
 	if opts.BPM {
-		metricsChan = make(chan *bpm.Metrics, 1)
+		bpmChan = make(chan provider.BPMKey, 1)
 		errChan = make(chan error, 1)
 		go func() {
-			metrics, err := bpm.FetchMetrics(ctx, c.deezerClient.Session.HttpClient, song.Artist, song.Title, song.Duration)
+			p := provider.BPMProvider{}
+			bpmKey, err := p.Fetch(ctx, c.deezerClient.Session.HttpClient, song.Artist, song.Title, song.Duration)
 			if err != nil {
 				errChan <- err
 				return
 			}
 
-			metricsChan <- metrics
+			bpmChan <- bpmKey
 		}()
 	}
 
@@ -230,10 +231,10 @@ func (c *Client) downloadSong(ctx context.Context, resource deezer.Resource, son
 		warnings = append(warnings, fmt.Sprintf("requested quality '%s' not available, using '%s' instead", opts.Quality, strings.ToLower(mediaFormat)))
 	}
 
-	metrics := &bpm.Metrics{}
+	bpmKey := provider.BPMKey{}
 	if opts.BPM {
 		select {
-		case metrics = <-metricsChan:
+		case bpmKey = <-bpmChan:
 		case err := <-errChan:
 			if !errors.Is(err, context.Canceled) {
 				warnings = append(warnings, fmt.Sprintf("failed to fetch BPM and key: %v", err))
@@ -246,7 +247,7 @@ func (c *Client) downloadSong(ctx context.Context, resource deezer.Resource, son
 		warnings = append(warnings, fmt.Sprintf("failed to fetch cover image: %v", err))
 	}
 
-	warnings = append(warnings, c.finalizeDownload(resource, song, outputPath, mediaFormat, cover, metrics)...)
+	warnings = append(warnings, c.finalizeDownload(resource, song, outputPath, mediaFormat, cover, bpmKey)...)
 
 	return warnings, nil
 }
@@ -308,10 +309,10 @@ func (c *Client) streamToFile(ctx context.Context, stream io.ReadCloser, outputP
 	return nil
 }
 
-func (c *Client) finalizeDownload(resource deezer.Resource, song *deezer.Song, outputPath, mediaFormat string, cover []byte, metrics *bpm.Metrics) []string {
+func (c *Client) finalizeDownload(resource deezer.Resource, song *deezer.Song, outputPath, mediaFormat string, cover []byte, bpmKey provider.BPMKey) []string {
 	var warnings []string
 
-	if err := tags.AddTags(resource, song, cover, outputPath, metrics.BPM, metrics.Key); err != nil {
+	if err := tags.AddTags(resource, song, cover, outputPath, bpmKey.BPM, bpmKey.Key); err != nil {
 		warnings = append(warnings, fmt.Sprintf("failed to add tags: %v", err))
 	}
 

internal/provider/bpm.go

@@ -1,4 +1,4 @@
-package bpm
+package provider
 
 import (
 	"bytes"
@@ -6,7 +6,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
-	"net/url"
+	neturl "net/url"
 	"regexp"
 	"strconv"
 	"strings"
@@ -14,30 +14,32 @@ import (
 	"github.com/PuerkitoBio/goquery"
 )
 
-type Metrics struct {
+type BPMProvider struct{}
+
+type BPMKey struct {
 	BPM string
 	Key string
 }
 
-func FetchMetrics(ctx context.Context, httpClient *http.Client, artist, title, duration string) (*Metrics, error) {
+func (p BPMProvider) Fetch(ctx context.Context, httpClient *http.Client, artist, title, duration string) (BPMKey, error) {
-	url, err := findSongURL(ctx, httpClient, artist, title, duration)
+	url, err := p.findSongURL(ctx, httpClient, artist, title, duration)
 	if err != nil {
-		return nil, err
+		return BPMKey{}, err
 	}
 
-	html, err := fetchPage(ctx, httpClient, url)
+	html, err := p.fetchPage(ctx, httpClient, url)
 	if err != nil {
-		return nil, err
+		return BPMKey{}, err
 	}
 
-	return parseMetrics(html)
+	return p.parse(html)
 }
 
-func findSongURL(ctx context.Context, httpClient *http.Client, artist, title, duration string) (string, error) {
+func (p BPMProvider) findSongURL(ctx context.Context, httpClient *http.Client, artist, title, duration string) (string, error) {
 	rootUrl := "https://songbpm.com"
 	reqUrl := rootUrl + "/searches"
 
-	values := url.Values{}
+	values := neturl.Values{}
 	values.Add("query", fmt.Sprintf("%s %s", artist, title))
 
 	req, err := http.NewRequestWithContext(ctx, "POST", reqUrl, bytes.NewBufferString(values.Encode()))
@@ -90,12 +92,13 @@ func findSongURL(ctx context.Context, httpClient *http.Client, artist, title, du
 		}
 
 		foundDuration := minutes*60 + seconds
-		duration, err := strconv.Atoi(duration)
+		wantDuration, err := strconv.Atoi(duration)
 		if err != nil {
 			return true
 		}
 
-		if foundDuration <= (duration-2) || foundDuration >= (duration+2) {
+		const durationToleranceSec = 2
+		if foundDuration <= (wantDuration-durationToleranceSec) || foundDuration >= (wantDuration+durationToleranceSec) {
 			return true
 		}
 
@@ -112,7 +115,7 @@ func findSongURL(ctx context.Context, httpClient *http.Client, artist, title, du
 	return rootUrl + url, nil
 }
 
-func fetchPage(ctx context.Context, httpClient *http.Client, url string) (string, error) {
+func (p BPMProvider) fetchPage(ctx context.Context, httpClient *http.Client, url string) (string, error) {
 	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
 	if err != nil {
 		return "", err
@@ -136,7 +139,7 @@ func fetchPage(ctx context.Context, httpClient *http.Client, url string) (string
 	return string(body), nil
 }
 
-func parseMetrics(html string) (*Metrics, error) {
+func (p BPMProvider) parse(html string) (BPMKey, error) {
 	bpmRegex := regexp.MustCompile(`tempo of <span[^>]*>(\d+) BPM`)
 	bpmMatch := bpmRegex.FindStringSubmatch(html)
 
@@ -147,7 +150,7 @@ func parseMetrics(html string) (*Metrics, error) {
 	modeMatch := modeRegex.FindStringSubmatch(html)
 
 	if len(bpmMatch) != 2 || len(keyMatch) != 2 || len(modeMatch) != 2 {
-		return nil, fmt.Errorf("no data found")
+		return BPMKey{}, fmt.Errorf("no data found")
 	}
 
 	isMinor := false
@@ -169,8 +172,9 @@ func parseMetrics(html string) (*Metrics, error) {
 		key += "m"
 	}
 
-	return &Metrics{
+	return BPMKey{
 		BPM: bpm,
 		Key: key,
 	}, nil
+
 }