app.py

from flask import Flask, jsonify, request, send_file, send_from_directory
import dotenv
import io
import os
import json
from ytmusicapi import YTMusic
from yt_dlp import YoutubeDL
from contextlib import redirect_stdout
import spotipy
from recomendation.recommender import getRecommendations

dotenv.load_dotenv()
app = Flask(__name__,
            static_url_path='/',
            static_folder='frontend/build')

spotify_client_id = os.getenv("SPOTIFY_CLIENT_ID")
spotify_client_secret = os.getenv("SPOTIFY_CLIENT_SECRET")
sp = spotipy.Spotify(client_credentials_manager=spotipy.oauth2.SpotifyClientCredentials(
    client_id=spotify_client_id,
    client_secret=spotify_client_secret
))

ytmusic = YTMusic()

def search_songs(search_term):
    results = sp.search(q=search_term, type='track', limit=10) # search_term="Perfect"

    with open("spotify_results.json", "w") as file:
        json.dump(results, file, indent=2)

    data = []
    for track in results['tracks']['items']:
        track_name = track['name']
        track_id = track['id']
        track_type = track['album']['album_type']
        preview_url = track['preview_url']
        artist_name = track['artists'][0]['name']
        thumbnail_url = track['album']['images'][0]['url']
        data.append({
            "title": track_name,
            "artist": artist_name,
            "image": thumbnail_url,
            "id": track_id,
            "preview_url": preview_url
        })

    with open("processed_results.json", "w") as file:
        json.dump(data, file, indent=2)

    return data

def get_youtube_id(song, artist):
    youtube_query = f"{song} {artist}" # Template String 
    search_results = ytmusic.search(youtube_query, "songs")

    with open("youtube_results", "w") as file:
        json.dump(search_results, file, indent=2)

    return search_results[0]['videoId']

def get_audio_features(trackId):
    results = sp.audio_features(trackId)
    return results[0]

def get_track_metadata(trackId_list):
    results = sp.tracks(trackId_list)

    data = []
    for track in results['tracks']:
        track_name = track['name']
        track_id = track['id']
        track_type = track['album']['album_type']
        preview_url = track['preview_url']
        artist_name = track['artists'][0]['name']
        thumbnail_url = track['album']['images'][0]['url']
        data.append({
            "title": track_name,
            "artist": artist_name,
            "image": thumbnail_url,
            "id": track_id,
            "preview_url": preview_url
        })

    with open("metadata.json", "w") as file:
        json.dump(data, file, indent=2)

    return data

    
@app.route('/')
def home():
    return send_from_directory('frontend/build', 'index.html')

@app.route('/api/stream')
def stream():
    artist = request.args.get("artist") # "Ed"
    song = request.args.get("song") # "Perfect"
    song_yt_id = get_youtube_id(song, artist)
    youtube_url = f"https://www.youtube.com/watch?v={song_yt_id}"
    ctx = {
        "outtmpl": "-",
        "logtostderr": True,
        "format": 'mp3/bestaudio/best',
        "postprocessors": [{
            "key": "FFmpegExtractAudio",
            "preferredcodec": "mp3"
        }]
    }

    buffer = io.BytesIO()
    with redirect_stdout(buffer), YoutubeDL(ctx) as ytdl:
        ytdl.download([youtube_url])

    return send_file(buffer, mimetype="audio/mpeg")

@app.route('/api/search', methods=["POST"])
def search():
    search = request.form['search_box'] # "Perfect"
    search_results = search_songs(search ) # "Perfect"
    return jsonify(search_results)

@app.route('/api/recommend/<trackId>')
def recommend(trackId):
    audio_features = get_audio_features(trackId)

    keys = [
        "acousticness", "danceability", "duration_ms", "energy", "instrumentalness", 
        "key", "liveness", "loudness", "mode", "speechiness", "tempo", "time_signature",
        "valence"
    ]
    query_vector = [audio_features.get(key) for key in keys]
    recommendations = getRecommendations(query_vector=query_vector) 
    
    with open("recommended_songs.json", "w") as file:
        json.dump(audio_features, file, indent=2)

    song_data = get_track_metadata([track.get("id") for track in recommendations])
    return jsonify(song_data)


if __name__ == "__main__":
    app.run(debug=True)