<?
authorize();

if (!check_perms('torrents_edit')) {
  error(403);
}
$ArtistID = $_POST['artistid'];
$Redirect = $_POST['redirect'];
$AliasName = Artists::normalise_artist_name($_POST['name']);
$DBAliasName = db_string($AliasName);
if (!$Redirect) {
  $Redirect = 0;
}

if (!is_number($ArtistID) || !($Redirect === 0 || is_number($Redirect)) || !$ArtistID) {
  error(0);
}

if ($AliasName == '') {
  error('Blank artist name.');
}

/*
 * In the case of foo, who released an album before changing his name to bar and releasing another
 * the field shared to make them appear on the same artist page is the ArtistID
 * 1. For a normal artist, there'll be one entry, with the ArtistID, the same name as the artist and a 0 redirect
 * 2. For Celine Dion (C�line Dion), there's two, same ArtistID, diff Names, one has a redirect to the alias of the first
 * 3. For foo, there's two, same ArtistID, diff names, no redirect
 */

$DB->query("
  SELECT AliasID, ArtistID, Name, Redirect
  FROM artists_alias
  WHERE Name = '$DBAliasName'");
if ($DB->has_results()) {
  while (list($CloneAliasID, $CloneArtistID, $CloneAliasName, $CloneRedirect) = $DB->next_record(MYSQLI_NUM, false)) {
    if (!strcasecmp($CloneAliasName, $AliasName)) {
      break;
    }
  }
  if ($CloneAliasID) {
    if ($ArtistID == $CloneArtistID && $Redirect == 0) {
      if ($CloneRedirect != 0) {
        $DB->query("
          UPDATE artists_alias
          SET ArtistID = '$ArtistID', Redirect = 0
          WHERE AliasID = '$CloneAliasID'");
        Misc::write_log("Redirection for the alias $CloneAliasID ($DBAliasName) for the artist $ArtistID was removed by user $LoggedUser[ID] ($LoggedUser[Username])");
      } else {
        error('No changes were made as the target alias did not redirect anywhere.');
      }
    } else {
      error('An alias by that name already exists <a href="artist.php?id='.$CloneArtistID.'">here</a>. You can try renaming that artist to this one.');
    }
  }
}
if (!$CloneAliasID) {
  if ($Redirect) {
    $DB->query("
      SELECT ArtistID, Redirect
      FROM artists_alias
      WHERE AliasID = $Redirect");
    if (!$DB->has_results()) {
      error('Cannot redirect to a nonexistent artist alias.');
    }
    list($FoundArtistID, $FoundRedirect) = $DB->next_record();
    if ($ArtistID != $FoundArtistID) {
      error('Redirection must target an alias for the current artist.');
    }
    if ($FoundRedirect != 0) {
      $Redirect = $FoundRedirect;
    }
  }
  $DB->query("
    INSERT INTO artists_alias
      (ArtistID, Name, Redirect, UserID)
    VALUES
      ($ArtistID, '$DBAliasName', $Redirect, ".$LoggedUser['ID'].')');
  $AliasID = $DB->inserted_id();

  $DB->query("
    SELECT Name
    FROM artists_group
    WHERE ArtistID = $ArtistID");
  list($ArtistName) = $DB->next_record(MYSQLI_NUM, false);

  Misc::write_log("The alias $AliasID ($DBAliasName) was added to the artist $ArtistID (".db_string($ArtistName).') by user '.$LoggedUser['ID'].' ('.$LoggedUser['Username'].')');
}
header('Location: '.$_SERVER['HTTP_REFERER']);
?>
