let token = null;
let authStuff = null;
const client_id = process.env.SPOTIFY_CLIENT_ID;
const client_secret = process.env.SPOTIFY_CLIENT_SECRET;
const redirect_uri = process.env.SPOTIFY_REDIRECT_URI;
async function fetchWebApi(endpoint, method, body) {
  const res = await fetch(`https://api.spotify.com/${endpoint}`, {
    headers: {
      Authorization: `Bearer ${token}`,
    },
    method,
    body: JSON.stringify(body),
  });
  const text = await res.text();
  // console.debug(text)
  // abs nothing is wrong
  return JSON.parse(text.trim());
}

function getLoginUrl() {
  const state = generateRandomString(16);
  const scope = [
    // "ugc-image-upload",
    // "user-read-playback-state",
    // "user-modify-playback-state",
    // "user-read-currently-playing",
    // "app-remote-control",
    // "streaming",
    "playlist-read-private",
    "playlist-read-collaborative",
    "playlist-modify-private",
    "playlist-modify-public",
    // "user-follow-modify",
    // "user-follow-read",
    // "user-read-playback-position",
    // "user-top-read",
    // "user-read-recently-played",
    "user-library-modify",
    // "user-library-read",
    // "user-read-email",
    "user-read-private",
  ].join(" ");

  return (
    "https://accounts.spotify.com/authorize?" +
    `response_type=code&grant_type=client_credentials&client_id=${client_id}&scope=${scope}&redirect_uri=${redirect_uri}&state=${state}`
  );
}

function generateRandomString(length) {
  let result = "";
  const characters =
    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
  const charactersLength = characters.length;
  let counter = 0;
  while (counter < length) {
    result += characters.charAt(Math.floor(Math.random() * charactersLength));
    counter += 1;
  }
  return result;
}
async function refreshToken(refresh_token) {
  try {
    // var refresh_token = req.query.refresh_token;
    const authOptions = {
      url: "https://accounts.spotify.com/api/token",
      headers: {
        "content-type": "application/x-www-form-urlencoded",
        Authorization:
          "Basic " +
          new Buffer.from(client_id + ":" + client_secret).toString("base64"),
      },
      form: {
        grant_type: "refresh_token",
        refresh_token: refresh_token,
      },
      json: true,
    };
    const formdm = new URLSearchParams();

    formdm.append("grant_type", "refresh_token");
    formdm.append("refresh_token", refresh_token);

    fetch(authOptions.url, {
      body: formdm,
      headers: authOptions.headers,
      method: "POST",
    })
      .then(async (r) => {
        const text = await r.text();
        // console.log(text);
        return JSON.parse(text);
      })
      .then((auth) => {
        if (!auth.refresh_token) auth.refresh_token = refresh_token;
        // console.log(auth);
        authStuff = auth;
        token = auth.access_token;
        saveCredentials(auth);
        if (auth.expires_in) {
          setTimeout(() => {
            refreshToken(auth.refresh_token);
          }, auth.expires_in * 1000);
        }
      });
  } catch (e) {
    console.error(`Welp it broke`);
    // try again asap because we NEED THAT TOKEN
    refreshToken(refresh_token);
  }
}
function saveCredentials(creds) {
  require("fs").writeFileSync(
    "data/credentials.json",
    JSON.stringify(creds, null, 2),
  );
}
function getCredentials() {
  try {
    return JSON.parse(
      require("fs").readFileSync("data/credentials.json", "utf8"),
    );
  } catch (e) {
    return null;
  }
}
function spotifyRoutes(app) {
  app.get("/spotify/callback", async (req, res) => {
    const code = req.query.code || null;
    const state = req.query.state || null;

    if (state === null) {
      res.redirect(
        "/#" +
          querystring.stringify({
            error: "state_mismatch",
          }),
      );
    } else {
      const authOptions = {
        url: "https://accounts.spotify.com/api/token",
        form: {
          code: code,
          redirect_uri: redirect_uri,
          grant_type: "authorization_code",
        },
        headers: {
          "content-type": "application/x-www-form-urlencoded",
          Authorization:
            "Basic " +
            new Buffer.from(client_id + ":" + client_secret).toString("base64"),
        },
        json: true,
      };
      const formdm = new URLSearchParams();
      // Object.entries(authOptions.form).forEach(([key, value]) => {
      //   formdm.append(key, value);
      // })
      formdm.append("code", code);
      formdm.append("redirect_uri", redirect_uri);
      formdm.append("grant_type", "authorization_code");

      fetch(authOptions.url, {
        body: formdm,
        headers: authOptions.headers,
        method: "POST",
      })
        .then((r) => r.json())
        .then((auth) => {
          // console.log(auth);
          authStuff = auth;
          saveCredentials(auth);
          token = auth.access_token;
          if (auth.expires_in) {
            setTimeout(() => {
              refreshToken(auth.refresh_token);
            }, auth.expires_in * 1000);
          }
          res.status(200).end("Successfully logged in!");
        });
    }
  });
}
function addSongToPlaylist(url) {
  fetchWebApi("v1/playlists/3gRv97fvllFFLVdCH6XzsE/tracks", "POST", {
    uris: [url],
    position: 0,
  });
}
module.exports = {
  getLoginUrl,
  refreshToken,
  saveCredentials,
  getCredentials,
  spotifyRoutes,
  addSongToPlaylist,

  // getToken
};