init

go.mod

@@ -0,0 +1,3 @@
+module music-downloader
+
+go 1.25.0

main.go

@@ -0,0 +1,136 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"music-downloader/monochrome"
+	"net/http"
+	"os"
+	"path"
+	"strconv"
+	"sync"
+)
+
+func sendJSON(w http.ResponseWriter, data any, status int) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	if err := json.NewEncoder(w).Encode(data); err != nil {
+		http.Error(w, err.Error(), 500)
+	}
+}
+
+func main() {
+	mClient := monochrome.NewClient(monochrome.ClientConfig{
+		ApiURL: "https://api.monochrome.tf",
+	})
+
+	mux := http.NewServeMux()
+
+	mux.HandleFunc("GET /search", func(w http.ResponseWriter, r *http.Request) {
+		q := r.URL.Query().Get("q")
+
+		results, err := mClient.SearchAlbum(q)
+		if err != nil {
+			http.Error(w, err.Error(), 404)
+			return
+		}
+
+		sendJSON(w, results, 200)
+	})
+
+	mux.HandleFunc("GET /download-album/{id}", func(w http.ResponseWriter, r *http.Request) {
+		id, err := strconv.Atoi(r.PathValue("id"))
+		if err != nil {
+			http.Error(w, err.Error(), 500)
+			return
+		}
+
+		album, err := mClient.AlbumInfo(id)
+		if err != nil {
+			http.Error(w, err.Error(), 404)
+			return
+		}
+
+		if album == nil {
+			http.Error(w, "album not found for some reason", 404)
+			return
+		}
+
+		if err := os.Mkdir("./music/"+album.Title, 0777); err != nil {
+			http.Error(w, fmt.Sprintf("failed to create album directory: %v", err), 500)
+			return
+		}
+
+		type Response struct {
+			sync.Mutex
+			count int
+		}
+		response := new(Response)
+
+		var wg sync.WaitGroup
+		for _, track := range album.Items {
+			wg.Go(func() {
+				info, err := mClient.TrackInfo(track.Item.ID, track.Item.AudioQuality)
+				if err != nil {
+					log.Printf("failed to get track info: %v\n", err)
+					return
+				}
+
+				manifest, err := mClient.DecodeManifest(info.Manifest)
+				if err != nil {
+					log.Printf("failed to decode track manifest: %v\n", err)
+					return
+				}
+
+				if manifest.EncryptionType != monochrome.TrackManifestEncryptionNone {
+					log.Println("file is encrypted; can't download")
+					return
+				}
+
+				if len(manifest.URLs) == 0 {
+					log.Println("track manifest doesn't have urls array")
+					return
+				}
+
+				resp, err := http.Get(manifest.URLs[0])
+				if err != nil {
+					log.Printf("failed to download track data: %v\n", err)
+					return
+				}
+				defer resp.Body.Close()
+
+				data, err := io.ReadAll(resp.Body)
+				if err != nil {
+					log.Printf("failed to read track data: %v\n", err)
+					return
+				}
+
+				if err := os.WriteFile(path.Join("./music/", album.Title, track.Item.Title+".flac"), data, 0644); err != nil {
+					log.Printf("failed to save track file: %v\n", err)
+					return
+				}
+
+				response.Lock()
+				response.count++
+				response.Unlock()
+			})
+		}
+
+		wg.Wait()
+
+		sendJSON(w, struct {
+			DownloadedFilesCount int `json:"downloadedFilesCount"`
+			TotalFilesCount      int `json:"totalFilesCount"`
+		}{
+			DownloadedFilesCount: response.count,
+			TotalFilesCount:      len(album.Items),
+		}, 200)
+	})
+
+	log.Println("starting http server")
+	if err := http.ListenAndServe(":5000", mux); err != nil {
+		log.Fatalf("failed to start http server: %v\n", err)
+	}
+}

monochrome/album.go

@@ -0,0 +1,62 @@
+package monochrome
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strconv"
+)
+
+type AlbumTrack struct {
+	Type string `json:"type"`
+	Item struct {
+		ID           int          `json:"id"`
+		Title        string       `json:"title"`
+		Duration     int          `json:"duration"`
+		TrackNumber  int          `json:"trackNumber"`
+		Explicit     bool         `json:"explicit"`
+		AudioQuality AudioQuality `json:"audioQuality"`
+	} `json:"item"`
+}
+
+type AlbumInfo struct {
+	ID             int            `json:"id"`
+	Title          string         `json:"title"`
+	Duration       int            `json:"duration"`
+	NumberOfTracks int            `json:"numberOfTracks"`
+	ReleaseDate    string         `json:"releaseDate"`
+	Type           SearchItemType `json:"type"`
+	CoverID        string         `json:"cover"`
+	VibrantColor   string         `json:"vibrantColor"`
+	Explicit       bool           `json:"explicit"`
+	Items          []AlbumTrack   `json:"items"`
+}
+
+type AlbumInfoResponse struct {
+	Data AlbumInfo `json:"data"`
+}
+
+func (c *Client) AlbumInfo(id int) (*AlbumInfo, error) {
+	req, err := http.NewRequest("GET", c.config.ApiURL+"/album", nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %v", err)
+	}
+
+	params := url.Values{}
+	params.Set("id", strconv.Itoa(id))
+	req.URL.RawQuery = params.Encode()
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to send request: %v", err)
+	}
+	defer resp.Body.Close()
+
+	response := AlbumInfoResponse{}
+	if err := json.NewDecoder(resp.Body).Decode(&response); err != nil {
+		return nil, fmt.Errorf("failed to decode json response: %v", err)
+	}
+
+	return &response.Data, nil
+}

monochrome/client.go

@@ -0,0 +1,15 @@
+package monochrome
+
+type ClientConfig struct {
+	ApiURL string
+}
+
+type Client struct {
+	config ClientConfig
+}
+
+func NewClient(config ClientConfig) *Client {
+	return &Client{
+		config: config,
+	}
+}

monochrome/search.go

@@ -0,0 +1,68 @@
+package monochrome
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+)
+
+type SearchItemType = string
+
+var (
+	SearchItemAlbum  SearchItemType = "ALBUM"
+	SearchItemSingle SearchItemType = "SINGLE"
+)
+
+type AudioQuality = string
+
+var (
+	AudioQualityLossless AudioQuality = "LOSSLESS"
+	AudioQualityLow      AudioQuality = "LOW"
+)
+
+type SearchAlbum struct {
+	ID             int            `json:"id"`
+	Title          string         `json:"title"`
+	Duration       int            `json:"duration"`
+	NumberOfTracks int            `json:"numberOfTracks"`
+	ReleaseDate    string         `json:"releaseDate"`
+	Type           SearchItemType `json:"type"`
+	URL            string         `json:"url"`
+	CoverID        string         `json:"cover"`
+	VibrantColor   string         `json:"vibrantColor"`
+	Explicit       bool           `json:"explicit"`
+	AudioQuality   AudioQuality   `json:"audioQuality"`
+}
+
+type SearchResponse struct {
+	Data struct {
+		Albums struct {
+			Items []SearchAlbum `json:"items"`
+		} `json:"albums"`
+	} `json:"data"`
+}
+
+func (c *Client) SearchAlbum(q string) ([]SearchAlbum, error) {
+	req, err := http.NewRequest("GET", c.config.ApiURL+"/search", nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %v", err)
+	}
+
+	params := url.Values{}
+	params.Set("al", q)
+	req.URL.RawQuery = params.Encode()
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to send request: %v", err)
+	}
+	defer resp.Body.Close()
+
+	response := SearchResponse{}
+	if err := json.NewDecoder(resp.Body).Decode(&response); err != nil {
+		return nil, fmt.Errorf("failed to decode json response: %v", err)
+	}
+
+	return response.Data.Albums.Items, nil
+}

monochrome/tracks.go

@@ -0,0 +1,72 @@
+package monochrome
+
+import (
+	"bytes"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strconv"
+)
+
+type TrackInfo struct {
+	TrackId  int    `json:"trackId"`
+	Manifest string `json:"manifest"`
+}
+
+type TrackInfoResponse struct {
+	Data TrackInfo `json:"data"`
+}
+
+func (c *Client) TrackInfo(id int, quality AudioQuality) (*TrackInfo, error) {
+	req, err := http.NewRequest("GET", c.config.ApiURL+"/track", nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %v", err)
+	}
+
+	params := url.Values{}
+	params.Set("id", strconv.Itoa(id))
+	params.Set("quality", quality)
+	req.URL.RawQuery = params.Encode()
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to send request: %v", err)
+	}
+	defer resp.Body.Close()
+
+	response := TrackInfoResponse{}
+	if err := json.NewDecoder(resp.Body).Decode(&response); err != nil {
+		return nil, fmt.Errorf("failed to decode json response: %v", err)
+	}
+
+	return &response.Data, nil
+}
+
+type TrackManifestEncryption = string
+
+var (
+	TrackManifestEncryptionNone TrackManifestEncryption = "NONE"
+)
+
+type TrackManifest struct {
+	MimeType       string                  `json:"mimeType"`
+	Codecs         string                  `json:"codecs"`
+	EncryptionType TrackManifestEncryption `json:"encryptionType"`
+	URLs           []string                `json:"urls"`
+}
+
+func (c *Client) DecodeManifest(manifest string) (*TrackManifest, error) {
+	m, err := base64.StdEncoding.DecodeString(manifest)
+	if err != nil {
+		return nil, fmt.Errorf("failed to decode track manifest: %v", err)
+	}
+
+	mData := &TrackManifest{}
+	if err := json.NewDecoder(bytes.NewReader(m)).Decode(mData); err != nil {
+		return nil, fmt.Errorf("failed to decode track manifest: %v", err)
+	}
+
+	return mData, nil
+}