<?php

/**

 * Utility functions

 * 

 * Greyhound - real web management for Amarok

 * Copyright (C) 2008 Dan Fuhry

 *

 * This program is Free Software; you can redistribute and/or modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied

 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for details.

 */

/**

 * Utility/reporting functions

 */

/**

 * Report a fatal error and exit

 * @param string Error message

 */

function burnout($msg)

{

  global $use_colors;

  $h = @fopen('php://stderr', 'w');

  if ( $use_colors )

  {

    fwrite($h, "\x1B[31;1m[Greyhound] fatal: \x1B[37;1m");

    fwrite($h, "$msg\x1B[0m\n");

  }

  else

  {

    fwrite($h, "[Greyhound] fatal: $msg\n");

  }

  fclose($h);

  exit(1);

}

/**

 * Print a stylized status message, compatible with Linux consoles. Falls back to no control characters if on unsupported terminal.

 * @param string Status message

 */

function status($msg)

{

  global $use_colors;

  $h = @fopen('php://stderr', 'w');

  $label = ( defined('HTTPD_WS_CHILD') ) ? 'Child ' . substr(strval(getmypid()), -3) : 'Greyhound';

  if ( $use_colors )

  {

    fwrite($h, "\x1B[32;1m[$label] \x1B[32;0m$msg\x1B[0m\n");

  }

  else

  {

    fwrite($h, "[$label] $msg\n");

  }

  fclose($h);

}

/**

 * Print a stylized warning message, compatible with Linux consoles

 * @param string message message

 */

function warning($msg)

{

  global $use_colors;

  $h = @fopen('php://stderr', 'w');

  if ( $use_colors )

  {

    fwrite($h, "\x1B[33;1m[Greyhound] \x1B[0m\x1B[33mWarning:\x1B[0m $msg\n");

  }

  else

  {

    fwrite($h, "[Greyhound] Warning: $msg\n");

  }

  fclose($h);

}

/**

 * Performs an action with DCOP.

 * @param string DCOP component, e.g. player, playlist, playlistbrowser, ...

 * @param string Action to perform, e.g. stop, play, ...

 * @param string additional parameters... (NOT IMPLEMENTED)

 * @return mixed output of DCOP command

 */

function dcop_action($component, $action)

{

  file_put_contents('php://stderr', "[dcop] start...");

  if ( function_exists('proc_open') )

  {

    $descriptorspec = array(

        0 => array('pipe', 'r'),

        1 => array('pipe', 'w'),

        2 => array('pipe', 'w')

      );

    $dcop_command = "dcop amarok $component $action";

    $dcop_process = proc_open($dcop_command, $descriptorspec, $dcop_pipes);

    do

    {

      $status = proc_get_status($dcop_process);

      usleep(2000);

    } while ( $status['running'] );

    pcntl_waitpid($status['pid'], $status);

    $output = fgets($dcop_pipes[1], 1024);

    proc_close($dcop_process);

  }

  else

  {

    $tmpfile = tempnam('amaweb', '');

    if ( !$tmpfile )

      burnout('tempnam() failed us');

    // This is freezing up for some reason.

    system("dcop amarok $component $action > $tmpfile");

    $output = @file_get_contents($tmpfile);

    @unlink($tmpfile);

  }

  file_put_contents('php://stderr', "got it...\r");

  $output = trim($output);

  // detect type of output

  if ( $output == 'true' )

    return true;

  else if ( $output == 'false' )

    return false;

  else if ( preg_match('/^-?[0-9]+/', $output) )

    return intval($output);

  else

    return $output;

}

/**

 * Rebuilds the copy of the playlist in RAM

 */

$playlist_last_md5 = '';

function rebuild_playlist($force = false, $from_ipc = false)

{

  // import what we need

  global $playlist, $amarok_home;

  // sync and load the playlist file

  // if we're coming from IPC, don't call DCOP, just load the existing file

  // this prevents the file from being generated 20 times and thus sometimes

  // causing simplexml to read a half-written file

  if ( !$from_ipc )

  {

    $playlist_file = dcop_action('playlist', 'saveCurrentPlaylist');

  }

  else

  {

    $playlist_file = $from_ipc;

  }

  // do we have amarok's home?

  if ( !$amarok_home )

    $amarok_home = dirname($playlist_file);

  // check MD5 - if it's not changed, exit to save CPU cycles

  global $playlist_last_md5;

  $effective_md5 = md5_playlist_file($playlist_file);

  if ( $playlist_last_md5 == $effective_md5 && !$force )

  {

    return true;

  }

  status('Rebuilding playlist cache');

  $playlist_last_md5 = $effective_md5;

  $originalplaylist = $playlist_file;

  $xml = false;

  $unlinkplaylist = false;

  while ( !$xml )

  {

    // start XML parser

    try

    {

      $xml = @simplexml_load_file($playlist_file);

      if ( $xml )

        break;

      // if we can't load it, just wait - another process might have it loaded

      warning('Could not load playlist file; maybe another Greyhound thread has it loaded? Waiting half a second.');

      usleep(500000);

    }

    catch ( Exception $e )

    {

      burnout("Caught exception trying to load playlist file:\n$e");

    }

  }

  $attribs = $xml->attributes();

  if ( @$attribs['product'] != 'Amarok' )

  {

    burnout('Playlist is not in Amarok format');

  }

  $playlist = array();

  foreach ( $xml->children() as $child )

  {

    $attribs = $child->attributes();

    $item = array(

        'uri'    => $attribs['uri'],

        'title'  => strval($child->Title),

        'artist' => strval($child->Artist),

        'album'  => strval($child->Album),

        'length' => seconds_to_str(intval($child->Length)),

        'length_int' => intval($child->Length)

      );

    $playlist[] = $item;

  }

  if ( $unlinkplaylist )

  {

    unlink($playlist_file);

  }

  // tell all other worker threads to reload the playlist as well

  global $httpd;

  if ( is_object($httpd) && !$from_ipc )

  {

    $httpd->threader->ipc_send(array(

        'action' => 'reloadplaylist',

        'propagate' => true,

        'playlist_file' => $playlist_file

      ));

  }

}

function rebuild_playlist_ipc($command, $threader)

{

  status('IPC playlist rebuild received');

  if ( isset($command['playlist']) )

  {

    status('IPC playlist rebuild: using playlist sent in IPC packet; length: ' . strlen($command['playlist']));

    $GLOBALS['playlist'] = $command['playlist'];

  }

  else

  {

    rebuild_playlist(true, $command['playlist_file']);

  }

}

/**

 * Builds the correct MD5 check for the specified playlist XML file. This is designed to base on the list of actual tracks, disregarding

 * the rest of the text in the XML file.

 * @param string Path to playlist

 * @return string hash

 */

function md5_playlist_file($file)

{

  $contents = @file_get_contents($file);

  if ( empty($contents) )

    return false;

  $count = preg_match_all('/uniqueid="([a-fA-F0-9]+?)"/', $contents, $matches);

  $matches = implode("", $matches[1]);

  if ( empty($matches) )

  {

    // sometimes current.xml has blank unique IDs

    $count = preg_match_all('/url="([^"]+?)"/', $contents, $matches);

    $matches = implode("", $matches[1]);

  }

  return md5($matches);

}

/**

 * Converts a number to minute:second format

 * @param int Seconds

 * @return string format: mm:ss

 */

function seconds_to_str($secs)

{

  $seconds = $secs % 60;

  $minutes = ( $secs - $seconds ) / 60;

  $seconds = strval($seconds);

  $minutes = strval($minutes);

  if ( strlen($seconds) < 2 )

    $seconds = "0$seconds";

  if ( strlen($minutes) < 2 )

    $minutes = "0$minutes";

  return "$minutes:$seconds";

}

/**

 * Loads the specified theme into Smarty

 * @param string Theme ID

 * @return object Smarty object

 */

function load_theme($theme_id)

{

  global $httpd;

  static $smarty = array();

  if ( $theme_id === '__free__' )

  {

    $smarty = array();

    return false;

  }

  if ( !isset($smarty[$theme_id]) )

  {

    $smarty[$theme_id] = new Smarty();

    $smarty[$theme_id]->template_dir = GREY_ROOT . "/themes/$theme_id";

    if ( !is_dir("./compiled/$theme_id") )

      @mkdir("./compiled/$theme_id");

    $smarty[$theme_id]->compile_dir  = "./compiled/$theme_id";

    $smarty[$theme_id]->config_dir = "./config";

    $httpd->add_handler("themes/$theme_id", 'dir', GREY_ROOT . "/themes/$theme_id");

  }

  return $smarty[$theme_id];

}

/**

 * Implementation of the "which" command in native PHP.

 * @param string command

 * @return string path to executable, or false on failure

 */

function which($executable)

{

  $path = ( isset($_ENV['PATH']) ) ? $_ENV['PATH'] : ( isset($_SERVER['PATH']) ? $_SERVER['PATH'] : false );

  if ( !$path )

    // couldn't get OS's PATH

    return false;

  $win32 = ( PHP_OS == 'WINNT' || PHP_OS == 'WIN32' );

  $extensions = $win32 ? array('.exe', '.com', '.bat') : array('');

  $separator = $win32 ? ';' : ':';

  $paths = explode($separator, $path);

  foreach ( $paths as $dir )

  {

    foreach ( $extensions as $ext )

    {

      $fullpath = "$dir/{$executable}{$ext}";

      if ( file_exists($fullpath) && is_executable($fullpath) )

      {

        return $fullpath;

      }

    }

  }

  return false;

}

/**

 * Reload the config.

 */

function grey_reload_config()

{

  global $httpd;

  status('reloading the config');

  if ( file_exists('./greyhound-config.php') )

  {

    require('./greyhound-config.php');

  }

  else

  {

    // ignore this, it allows using a different config file when a Mercurial repository

    // exists in Greyhound's root directory (to allow the devs to have their own config

    // separate from the default)

    if ( @is_dir(GREY_ROOT . '/.hg') )

    {

      require(GREY_ROOT . '/config.dev.php');

    }

    else

    {

      require(GREY_ROOT . '/config.php');

    }

  }

  foreach ( array('public', 'enable_ipv4', 'enable_ipv6', 'allowcontrol', 'theme', 'allow_fork', 'use_auth', 'auth_data', 'configpass') as $var )

  {

    if ( isset($$var) )

    {

      $GLOBALS[$var] = $$var;

    }

  }

}

/**

 * Decodes a hex string.

 * @param string $hex The hex code to decode

 * @return string

 */

function hexdecode($hex)

{

  $hex = str_split($hex, 2);

  $bin_key = '';

  foreach($hex as $nibble)

  {

    $byte = chr(hexdec($nibble));

    $bin_key .= $byte;

  }

  return $bin_key;

}