Vocard/voicelink/spotify/client.py

"""MIT License

Copyright (c) 2022 Vocard Development

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
"""

import re
import time
from base64 import b64encode

import aiohttp

from .objects import Track, Album, Artist, Playlist
from .exceptions import InvalidSpotifyURL, SpotifyRequestException

GRANT_URL = "https://accounts.spotify.com/api/token"
REQUEST_URL = "https://api.spotify.com/v1/{type}s/{id}"
SEARCH_URL = "https://api.spotify.com/v1/search?q={query}&type={type}&limit={limit}"
SUGGESTION_URL = "https://api.spotify.com/v1/recommendations?limit={limit}&seed_tracks={seed_tracks}"
SUGGESTION_URL_WITH_ART = "https://api.spotify.com/v1/recommendations?limit={limit}&seed_artists={seed_artists}&seed_tracks={seed_tracks}"
SPOTIFY_URL_REGEX = re.compile(
    r"https?://open.spotify.com/(?P<type>album|playlist|track|artist)/(?P<id>[a-zA-Z0-9]+)"
)

class Client:
    """The base client for the Spotify module of Voicelink.
       This class will do all the heavy lifting of getting all the metadata 
       for any Spotify URL you throw at it.
    """

    def __init__(self, client_id: str, client_secret: str) -> None:
        self._client_id = client_id
        self._client_secret = client_secret

        self.session = aiohttp.ClientSession()

        self._bearer_token: str = None
        self._expiry = 0
        self._auth_token = b64encode(f"{self._client_id}:{self._client_secret}".encode())
        self._grant_headers = {"Authorization": f"Basic {self._auth_token.decode()}"}
        self._bearer_headers = None

    async def _fetch_bearer_token(self) -> None:
        _data = {"grant_type": "client_credentials"}

        async with self.session.post(GRANT_URL, data=_data, headers=self._grant_headers) as resp:
            if resp.status != 200:
                raise SpotifyRequestException(
                    f"Error fetching bearer token: {resp.status} {resp.reason}"
                )

            data: dict = await resp.json()

        self._bearer_token = data["access_token"]
        self._expiry = time.time() + (int(data["expires_in"]) - 10)
        self._bearer_headers = {"Authorization": f"Bearer {self._bearer_token}"}

    async def trackSearch(self, query: str, track: str = "track", limit: int = 10) -> list:
        if not self._bearer_token or time.time() >= self._expiry:
            await self._fetch_bearer_token()

        request_url = SEARCH_URL.format(query=query, type=track, limit=limit)

        async with self.session.get(request_url, headers=self._bearer_headers) as resp:
            if resp.status != 200:
                raise SpotifyRequestException(
                    f"Error while fetching results: {resp.status} {resp.reason}"
                )
            
            data: dict = await resp.json()

        return [ Track(track) for track in data['tracks']['items'] ]

    async def similar_track(self, seed_tracks: str, *, seed_artists: str = None, limit: int = 5) -> list:
        if not self._bearer_token or time.time() >= self._expiry:
            await self._fetch_bearer_token()
        
        if not seed_artists:
            request_url = SUGGESTION_URL.format(limit=limit, seed_tracks=seed_tracks)
        else:
            request_url = SUGGESTION_URL_WITH_ART.format(limit=limit, seed_artists=seed_artists, seed_tracks=seed_tracks)
        
        async with self.session.get(request_url, headers=self._bearer_headers) as resp:
            if resp.status != 200:
                raise SpotifyRequestException(
                    f"Error while fetching results: {resp.status} {resp.reason}"
                )
            
            data: dict = await resp.json()

            return [ Track(track) for track in data['tracks'] ]
            
    async def search(self, *, query: str):
        if not self._bearer_token or time.time() >= self._expiry:
            await self._fetch_bearer_token()

        result = SPOTIFY_URL_REGEX.match(query)
        spotify_type = result.group("type")
        spotify_id = result.group("id")

        if not result:
            raise InvalidSpotifyURL("The Spotify link provided is not valid.")

        request_url = REQUEST_URL.format(type=spotify_type, id=spotify_id)
        if isArtist := (spotify_type == "artist"):
            request_url += "/top-tracks?market=US"

        async with self.session.get(request_url, headers=self._bearer_headers) as resp:
            if resp.status != 200:
                raise SpotifyRequestException(
                    f"Error while fetching results: {resp.status} {resp.reason}"
                )

            data: dict = await resp.json()

        if spotify_type == "track":
            return Track(data)
        elif spotify_type == "album":
            return Album(data)
        elif isArtist:
            return Artist(data)
        else:
            tracks = [
                Track(track["track"])
                for track in data["tracks"]["items"] if track["track"] is not None
            ]

            if not tracks:
                raise SpotifyRequestException("This playlist is empty and therefore cannot be queued.")
                
            next_page_url = data["tracks"]["next"]

            while next_page_url is not None:
                async with self.session.get(next_page_url, headers=self._bearer_headers) as resp:
                    if resp.status != 200:
                        raise SpotifyRequestException(
                            f"Error while fetching results: {resp.status} {resp.reason}"
                        )

                    next_data: dict = await resp.json()

                tracks += [
                    Track(track["track"])
                    for track in next_data["items"] if track["track"] is not None
                ]
                next_page_url = next_data["next"]

            return Playlist(data, tracks)
    
    async def close(self):
        await self.session.close()