const clientId = '618b30d801214487ac0daa014e9658dd';
const redirectUri = "http://localhost:3000/";

let accessToken;

const Spotify = {
  getAccessToken() {
    if(accessToken) {
      return accessToken;
    } else {
      //check for access token match
      const accessTokenMatch = window.location.href.match(/access_token=([^&]*)/);
      const expiresInMatch = window.location.href.match(/expires_in=([^&]*)/);

      if(accessTokenMatch && expiresInMatch) {
        accessToken = accessTokenMatch[1];
        const expiresIn = Number(expiresInMatch[1]);

        //this clears the parameters, allowing us to grab a new access token when it expires.
        window.setTimeout(() => accessToken = '', expiresIn * 1000);
        window.history.pushState('Access Token', null, '/');
        return accessToken;
      } else {
        const accessUrl = `https://accounts.spotify.com/authorize?client_id=${clientId}&response_type=token&scope=playlist-modify-public&redirect_uri=${redirectUri}`;
        window.location = accessUrl;
      }
    }
  },

  search(term) {
    const accessToken = Spotify.getAccessToken();
    return fetch(`https://api.spotify.com/v1/search?type=track&q=${term}`, {
      headers: {
        Authorization: `Bearer ${accessToken}`
      }
    }).then(response => {
      return response.json();
    }).then(jsonResponse => {
      if(!jsonResponse.tracks) {
        return [];
      }
      return jsonResponse.tracks.items.map(track => ({
        id: track.id,
        name: track.name,
        artist: track.artists[0].name,
        album: track.album.name,
        uri: track.uri
      }));
    });
  },

  savePlaylist(name, trackUris) {
    if(!name || !trackUris.length) {
      return;
    }

    const accessToken = Spotify.getAccessToken();
    const headers = {Authorization: `Bearer ${accessToken}`};
    let userId;

    return fetch('https://api.spotify.com/v1/me', {headers: headers}
    ).then(response => response.json()
    ).then(jsonResponse => {
      userId = jsonResponse.id;
      return fetch(`https://api.spotify.com/v1/users/${userId}/playlists`,
        {
          headers: headers,
          method: 'POST',
          body: JSON.stringify({name: name})
        }).then(response => response.json()
        ).then(jsonResponse => {
          const playlistId = jsonResponse.id;
          return fetch(`https://api.spotify.com/v1/users/${userId}/playlists/${playlistId}/tracks`, {
            headers: headers,
            method: 'POST',
            body: JSON.stringify({ uris: trackUris})
          })
        })
    })
  }
}


export default Spotify;