/**
 * Implements hook_requirements().
 */
function godiagram_requirements($phase) {
  $requirements = array();

  if ($phase == 'install') {
    $t = get_t();

    $requirements['sltxt2png'] = array(
      'title' => $t('SL Txt 2 PNG'),
    );

    if (!function_exists('libraries_get_path')) {
      module_load_include('module', 'libraries');
    }

    $sltxt2png_path = libraries_get_path('sltxt2png');

    if (!is_file($sltxt2png_path . '/sltxt2png.php')) {
      $requirements['sltxt2png']['description'] = $t(
        '<h2>SL Txt 2 PNG library not installed</h2><br />' .
        'You are missing the required files for the SL Txt 2 PNG library. Please download the library from !sltxt2png_url and unzip the files to !sltxt2png_path. After doing this, confirm that the following path exists: !sltxt2png_php_path.',
        array(
          '!sltxt2png_url' => l(
            'http://senseis.xmp.net/?GoWiki%2FSLTxt2PNG',
            'http://senseis.xmp.net/?GoWiki%2FSLTxt2PNG',
            array(
              'external' => TRUE,
            )
          ),
          '!sltxt2png_path' => $sltxt2png_path,
          '!sltxt2png_php_path' => $sltxt2png_path . '/sltxt2png.php',
        )
      );
      $requirements['sltxt2png']['severity'] = REQUIREMENT_ERROR;
    }
    else {
      $requirements['sltxt2png']['severity'] = REQUIREMENT_OK;
    }
  }

  return $requirements;
}