Resolve "Create playlist from top played artists"

Closes #7 (closed)

public/index.php

@@ -43,6 +43,7 @@ $user = $api->me();
 $templateData = [
   'user' => $user,
   'playlists' => [],
+  'topArtists' => [],
 
   'infos' => [],
   'errors' => [],
@@ -53,6 +54,8 @@ if (isset($_GET['playlist'])) {
     $selectedPlaylistId = $_GET['playlist'];
 }
 
+$generatePlaylistFromArtists = isset($_GET['generate-playlist-top-artists']);
+
 if ($selectedPlaylistId) {
     $playlist = $api->getPlaylist($selectedPlaylistId);
     error_log('Will create new playlist from tracks in playlist '.$selectedPlaylistId.' "'.$playlist->name.'".');
@@ -88,10 +91,51 @@ if ($selectedPlaylistId) {
         'name' => $newPlaylistName,
     ]);
 
+    $api->replacePlaylistTracks($newPlaylist->id, $pickedTrackIds);
+    $playlistLink = '<a href="'.$newPlaylist->external_urls->spotify.'">'.$newPlaylistName.'</a>';
+    $templateData['infos'][] = 'Ok created new playlist with '.count($pickedTrackIds).' tracks: '.$playlistLink;
+} elseif ($generatePlaylistFromArtists) {
+    $selectedArtists = $_GET['selected-artist'];
+    error_log('Will create new playlist with filterted recommendations from artists: '.join(', ', $selectedArtists).'".');
+    $recommendedTrackIds = [];
+
+    foreach ($selectedArtists as $selectedArtist) {
+        error_log('Get recommendations for artist '.$selectedArtist.'');
+        $recommendations = $api->getRecommendations([
+            'seed_artists' => $selectedArtist,
+            'limit' => 100
+        ]);
+        error_log(' -> Got '.count($recommendations->tracks).' recommendatations.');
+
+        // Filter by artist, remove duplicates
+        foreach ($recommendations->tracks as $recommendedTrack) {
+            $trackArtistInWantedArtists = false;
+            foreach ($recommendedTrack->artists as $trackArtist) {
+                if (\in_array($trackArtist->id, $selectedArtists)) {
+                    $recommendedTrackIds[$recommendedTrack->id] = 1;
+                }
+            }
+        }
+    }
+
+    $recommendedTrackIds = array_keys($recommendedTrackIds);
+    error_log('=> Got '.count($recommendedTrackIds).' unique recommendatations.');
+    shuffle($recommendedTrackIds);
+    $pickedTrackIds = array_slice($recommendedTrackIds, 0, 50);
+    error_log('Keep '.count($pickedTrackIds).' random tracks.');
+
+    $now = new DateTime();
+    $newPlaylistName = 'Fresh playlist ['.$now->format('Y-m-d H:i:s').']';
+    error_log('Create new playlist "'.$newPlaylistName.'".');
+    $newPlaylist = $api->createPlaylist([
+        'name' => $newPlaylistName,
+    ]);
+
     $api->replacePlaylistTracks($newPlaylist->id, $pickedTrackIds);
     $playlistLink = '<a href="'.$newPlaylist->external_urls->spotify.'">'.$newPlaylistName.'</a>';
     $templateData['infos'][] = 'Ok created new playlist with '.count($pickedTrackIds).' tracks: '.$playlistLink;
 } else {
+    $templateData['topArtists'] = $api->getMyTop('artists', ['limit' => 16, 'time_range' => 'short_term'])->items;
     $templateData['playlists'] = $api->getUserPlaylists($user->id)->items;
 }