app.py

##########  IMPORTS   ##########
import os
import requests
import spotipy
from datetime import datetime

from flask import Flask, render_template, redirect, request, session

##########  FLASK CONFIG   ##########
app = Flask(__name__)
app.secret_key = os.getenv("FLASK_SECRET_KEY")


@app.route("/")
def home_page():
    return render_template("home.html")


##########  FUNCTIONS   ##########
def get_tracks(spotipy_obj, username, playlist_id):
    results = spotipy_obj.user_playlist(username, playlist_id, fields="tracks, next")
    temp_tracks = results["tracks"]

    original_tracks = temp_tracks["items"]

    while temp_tracks["next"]:
        temp_tracks = spotipy_obj.next(temp_tracks)

        original_tracks.extend(temp_tracks["items"])

    return original_tracks


def replace_tracks(sorted_tracks, sp, playlist_id, username, playlist):
    if playlist["owner"]["id"] == username:
        track_ids = []
        for sorted_track in sorted_tracks:
            track_ids.append(sorted_track["track"]["id"])
        if len(track_ids) > 100:
            chunks = [track_ids[x : x + 100] for x in range(0, len(track_ids), 100)]
            sp.user_playlist_replace_tracks(username, playlist_id, "")
            for track_ids in chunks:
                sp.user_playlist_add_tracks(username, playlist_id, track_ids)
        else:
            sp.user_playlist_replace_tracks(username, playlist_id, track_ids)
    else:
        create_playlist(sp, username, sorted_tracks, playlist_id, playlist)


def create_playlist(sp, username, sorted_tracks, playlist_id, playlist):
    track_ids = []
    for sorted_track in sorted_tracks:
        track_ids.append(sorted_track["track"]["id"])
    results = sp.user_playlist_create(
        user=username,
        name="Sortified " + playlist["name"],
        public=True,
        description="Playlist sorted using Sortify by @eliasbenb",
    )
    playlist_id = results["id"]
    chunks = [track_ids[x : x + 100] for x in range(0, len(track_ids), 100)]
    sp.user_playlist_replace_tracks(username, playlist_id, "")
    for track_ids in chunks:
        sp.user_playlist_add_tracks(username, playlist_id, track_ids)


def clean_artist(name: str):
    name = name.lower()
    words = [w for w in name.split() if w not in ["a", "an", "the"]]
    return " ".join(words)


def sort_by_key(items, key):
    return {
        "Alphabetical A-Z": sorted(items, key=lambda x: x["track"]["name"]),
        "Alphabetical Z-A": sorted(
            items, key=lambda x: x["track"]["name"], reverse=True
        ),
        "Artist": sorted(
            items, key=lambda x: clean_artist(x["track"]["artists"][0]["name"])
        ),
        "Chronological": sorted(
            items, key=lambda k: k["track"]["album"]["release_date"], reverse=True
        ),
        "Non-Chronological": sorted(
            items, key=lambda k: k["track"]["album"]["release_date"], reverse=False
        ),
        "Added At": sorted(
            items,
            key=lambda k: datetime.strptime(k["added_at"], "%Y-%m-%dT%H:%M:%SZ"),
            reverse=True,
        ),
    }[key]


##########  SPOTIFY AUTHENTICATION   ##########
SPOTIFY_CLIENT_ID = os.getenv("SPOTIFY_CLIENT_ID")
SPOTIFY_CLIENT_SECRET = os.getenv("SPOTIFY_CLIENT_SECRET")
SCOPE = "playlist-read-collaborative,playlist-read-private,playlist-modify-public,playlist-modify-private"
SPOTIFY_REDIRECT_URI = os.getenv("SPOTIFY_REDIRECT_URI")
API_BASE = "https://accounts.spotify.com"
SHOW_DIALOG = True


@app.route("/login")
def login_page():
    auth_url = f"{API_BASE}/authorize?client_id={SPOTIFY_CLIENT_ID}&response_type=code&redirect_uri={SPOTIFY_REDIRECT_URI}&scope={SCOPE}&show_dialog={SHOW_DIALOG}"
    return redirect(auth_url)


@app.route("/callback")
def callback():
    session.clear()
    code = request.args.get("code")

    auth_token_url = f"{API_BASE}/api/token"
    res = requests.post(
        auth_token_url,
        data={
            "grant_type": "authorization_code",
            "code": code,
            "redirect_uri": SPOTIFY_REDIRECT_URI,
            "client_id": SPOTIFY_CLIENT_ID,
            "client_secret": SPOTIFY_CLIENT_SECRET,
        },
    )

    res_body = res.json()
    session["token"] = res_body.get("access_token")

    return redirect("login_success")


@app.route("/login_success")
def login_success_page():
    return render_template("login_success.html")


##########  SORTIFY   ##########
def handle_request(index, key):
    sp = spotipy.Spotify(auth=session["token"])
    username = sp.current_user()["id"]
    playlists_soup = sp.current_user_playlists()
    playlist = playlists_soup["items"][index - 1]
    playlist_id = playlist["id"]

    original_tracks = []
    original_tracks.extend(get_tracks(sp, username, playlist_id))

    sorted_tracks = sort_by_key(original_tracks, key)
    replace_tracks(sorted_tracks, sp, playlist_id, username, playlist)

    if playlist["owner"]["id"] != username:
        index = 1
    return render_template("sorted.html", playlist=playlist, index=index)


@app.route("/playlists")
def playlists_page():
    try:
        sp = spotipy.Spotify(auth=session["token"])
        playlists_soup = sp.current_user_playlists()
        return render_template("playlists.html", playlists_soup=playlists_soup)
    except Exception:
        return redirect("login")


@app.route("/playlists/<int:index>")
def playlist_page(index):
    sp = spotipy.Spotify(auth=session["token"])
    username = sp.current_user()["id"]
    playlists_soup = sp.current_user_playlists()
    playlist = playlists_soup["items"][index - 1]
    playlist_id = playlist["id"]

    original_tracks = []
    original_tracks.extend(get_tracks(sp, username, playlist_id))
    results = sp.playlist(playlist["id"], fields="tracks,next")
    tracks = results["tracks"]
    return render_template(
        "playlist.html", playlist=playlist, tracks=tracks, index=index
    )


@app.route("/playlists/<int:index>/alphabetical-az")
def sort_by_alphabetical_az(index):
    return handle_request(index, "Alphabetical A-Z")


@app.route("/playlists/<int:index>/alphabetical-za")
def sort_by_alphabetical_za(index):
    return handle_request(index, "Alphabetical Z-A")


@app.route("/playlists/<int:index>/artist")
def sort_by_artist(index):
    return handle_request(index, "Artist")


@app.route("/playlists/<int:index>/release_date-chronological")
def sort_by_release_date_chronological(index):
    return handle_request(index, "Chronological")


@app.route("/playlists/<int:index>/release_date-non_chronological")
def sort_by_release_date_non_chronological(index):
    return handle_request(index, "Non-Chronological")


@app.route("/playlists/<int:index>/added_at")
def sort_by_added_at(index):
    return handle_request(index, "Added At")


##########  ERROR HANDLING   ##########
@app.errorhandler(404)
def error_404(_):
    return render_template("404.html"), 404


@app.errorhandler(500)
def error_500(_):
    return render_template("500.html"), 500


@app.route("/not_your_playlist")
def not_your_playlist_page():
    return render_template("not_your_playlist.html")


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