functions.php

<?php
    $band = $_GET["band"];

    function decodeJSON($id) {     
      $url = file_get_contents("https://api.spotify.com/v1/artists/" . $id);
      return json_decode($url, true); 
    }

    function findAlbums($band) {
      $id = getArtistId($band);

      $albums_info = file_get_contents("https://api.spotify.com/v1/artists/" . $id . "/albums?market=US&album_type=album,single");
      $result = json_decode($albums_info, true);
      $albums = $result["items"];

      $all_albums = array();
      foreach($albums as $album) {
        $full_info_url = $album["href"];
        $full_info = json_decode(file_get_contents($full_info_url), true);
        $name = $full_info["name"];
        if (!strpos($name, "Commentary")) {
          $all_albums[$name] = $full_info;
        }
      }

      return $all_albums;
    }

    function getArtistId($band) {
      $url = "https://api.spotify.com/v1/search?type=artist&q=" . str_replace(' ', '+', $band);

      if (strpos($url, "ó") !== FALSE){
        $url = str_replace("ó", "o", $url);
      }

      $json = file_get_contents($url);
      $results = json_decode($json, true);
      $top = $results["artists"]["items"][0];
      return $top["id"];
    }

    function getArtistURL($info) {
      return $info["external_urls"]["spotify"];
    }

    function getArtistFullName($info) {
      return $info["name"];
    }

    function getArtistFavicon($info) {
      return $info["images"][2]["url"]; 
    }

    function getArtistGenres($info) {
      return $info["genres"];
    }

    function getRandomTrack($info) {
      $tracks = $info["tracks"]["items"];
      $num_songs = count($tracks);
      $random_track = $tracks[rand(0, $num_songs - 1)];
      return $random_track;
    }

    function getTrackPreview($track) {
      return $track["preview_url"];
    }

    function getTrackURL($track) {
      return $track["external_urls"]["spotify"];
    }

    function getAlbumCover($info) {
      return $info["images"][1]["url"];
    }

    function getAlbumURL($info) {
      return $info["external_urls"]["spotify"];
    }

    function getYearRecorded($info) {
      $date = $info["release_date"];
      $fragments = explode("-", $date);
      return $fragments[0];
    }

    function getTrackList($info) {
      $track_list = array();
      $track_num = 1;
      $tracks = $info["tracks"]["items"];
      return $tracks;
    }

?>