<?php
// $Id$

/**
 * Load a file object from the database.
 *
 * @param $fid
 *   A numeric file id or string containing the file path.
 *
 * @param $reset
 *   Whether to reset the internal file_load cache.
 */
function field_file_load($fid, $reset = NULL) {
  static $files = array();

  if (empty($fid)) {
    return FALSE;
  }

  // Reset internal cache.
  if ($reset) {
    $files = array();
  }

  // Serve file from internal cache if available.
  if (!empty($fid) && !empty($files[$fid])) {
    return (array)$files[$fid];
  }

  if (is_numeric($fid)) {
    $file = db_fetch_object(db_query('SELECT f.* FROM {files} f WHERE f.fid = %d', $fid));
  }
  else {
    $file = db_fetch_object(db_query("SELECT f.* FROM {files} f WHERE f.filepath = '%s'", $fid));
  }

  if (!$file) {
    return FALSE;
  }

  foreach(module_implements('file') as $module) {
    $function =  $module .'_file';
    $function('load', $file);
  }

  // Cache the fully loaded value by both fid and filepath.
  // use non-copying objects to save memory.
  $files[$fid] = $file;
  $files[$file->filepath] = $file;

  // Cast to array for field. hook_file() expects objects as well as
  // core file functions.
  return (array)$file;
}

/**
 * Save a file upload to a new location. The source file is validated as a
 * proper upload and handled as such. By implementing hook_file($op = 'insert'),
 * modules are able to act on the file upload and to add their own properties
 * to the file.
 *
 * The file will be added to the files table as a temporary file. Temporary files
 * are periodically cleaned. To make the file permanent file call
 * file_set_status() to change its status.
 *
 * @param $source
 *   A string specifying the name of the upload field to save.
 * @param $validators
 *   An optional, associative array of callback functions used to validate the
 *   file. The keys are function names and the values arrays of callback
 *   parameters which will be passed in after the user and file objects. The
 *   functions should return an array of error messages, an empty array
 *   indicates that the file passed validation. The functions will be called in
 *   the order specified.
 * @param $dest
 *   A string containing the directory $source should be copied to. If this is
 *   not provided or is not writable, the temporary directory will be used.
 * @param $replace
 *   A boolean indicating whether an existing file of the same name in the
 *   destination directory should overwritten. A false value will generate a
 *   new, unique filename in the destination directory.
 * @return
 *   An array containing the file information, or 0 in the event of an error.
 */
function field_file_save_upload($source, $validators = array(), $dest = FALSE, $replace = FILE_EXISTS_RENAME) {
  if (!$file = file_save_upload($source, $validators, $dest, $replace)) {
    return 0;
  }
  // Let modules add additional file properties, and save initial values
  // to the database if they like to do so.
  foreach(module_implements('file') as $module) {
    $function =  $module .'_file';
    $function('insert', $file);
  }
  return (array)$file;
}

/**
 * Update an field item file. Delete marked items if neccessary and set new items as permamant.
 *
 * @param $node
 *    Node object this file is be associated with.
 * @param $file
 *    File to be inserted, passed by reference since fid should be attached.
 * @return array
 */
function field_file_save($node, &$file) {
  // If this item is marked for deletion.
  if (!empty($file['delete'])) {
    // If we're creating a new revision, return an empty array so CCK will
    // remove the item.
    if (!empty($node->old_vid)) {
      return array();
    }
    // Otherwise delete the file and return an empty array.
    if (field_file_delete($file)) {
      return array();
    }
  }

  // Set permanent status on files if unset.
  if (empty($file['status'])) {
    // Cast to object since core functions us objects.
    $file = (object)$file;
    file_set_status($file, FILE_STATUS_PERMANENT);
    $file = (array)$file;
  }

  // Let modules update their additional file properties too.
  foreach(module_implements('file') as $module) {
    $function =  $module .'_file';
    $function('update', $file);
  }
  return $file;
}

/**
 * Delete a field file and its database record.
 *
 * @param $path 
 *   A file object.
 * @param $force
 *   Force File Deletion ignoring reference counting.
 * @return mixed 
 *   TRUE for success, Array for reference count block, or FALSE in the event of an error.
 */
function field_file_delete($file, $force = FALSE) {
  $file = (object)$file;
  // If any module returns a value from the reference hook, the
  // file will not be deleted from Drupal, but file_delete will
  // return a populated array that tests as TRUE.
  if (!$force && $references = module_invoke_all('file', 'references', $file)) {
    return $references;
  }

  // Let other modules clean up on delete.
  module_invoke_all('file', 'delete', $file, $field);

  // Make sure the file is deleted before removing its row from the 
  // database, so UIs can still find the file in the database.
  if (file_delete($file->filepath)) {
    db_query('DELETE FROM {files} WHERE fid = %d', $file->fid);
    return TRUE;
  }
  return FALSE;
}

/**
 * A silent version of file.inc:file_check_directory it's only talkative
 * on errors.
 *
 * Check that the directory exists and is writable. Directories need to
 * have execute permissions to be considered a directory by FTP servers, etc.
 *
 * @param $directory A string containing the name of a directory path.
 * @param $mode A Boolean value to indicate if the directory should be created
 *   if it does not exist or made writable if it is read-only.
 * @param $form_item An optional string containing the name of a form item that
 *   any errors will be attached to. This is useful for settings forms that
 *   require the user to specify a writable directory. If it can't be made to
 *   work, a form error will be set preventing them from saving the settings.
 * @return FALSE when directory not found, or TRUE when directory exists.
 */
function field_file_check_directory(&$directory, $mode = 0, $form_item = NULL) {
  $directory = rtrim($directory, '/\\');

  // Check if the directory exists.
  if (!is_dir($directory)) {
    if (($mode & FILE_CREATE_DIRECTORY) && @mkdir($directory)) {
      @chmod($directory, 0775); // Necessary for non-webserver users.
    }
    else {
      if ($form_item) {
        form_set_error($form_item, t('The directory %directory does not exist.', array('%directory' => $directory)));
      }
      watchdog('file system', 'The directory %directory does not exist.', array('%directory' => $directory), WATCHDOG_ERROR);
      return FALSE;
    }
  }

  // Check to see if the directory is writable.
  if (!is_writable($directory)) {
    if (($mode & FILE_MODIFY_PERMISSIONS) && !@chmod($directory, 0775)) {
      if ($form_item) {
        form_set_error($form_item, t('The directory %directory is not writable', array('%directory' => $directory)));
      }
      watchdog('file system', 'The directory %directory is not writable, because it does not have the correct permissions set.', array('%directory' => $directory), WATCHDOG_ERROR);
      return FALSE;
    }
  }

  if ((file_directory_path() == $directory || file_directory_temp() == $directory) && !is_file("$directory/.htaccess")) {
    $htaccess_lines = "SetHandler Drupal_Security_Do_Not_Remove_See_SA_2006_006\nOptions None\nOptions +FollowSymLinks";
    if (($fp = fopen("$directory/.htaccess", 'w')) && fputs($fp, $htaccess_lines)) {
      fclose($fp);
      chmod($directory .'/.htaccess', 0664);
    }
    else {
      $message =  "Security warning: Couldn't write .htaccess file. Please create a .htaccess file in your %directory directory which contains the following lines: <code>!htaccess</code>";
      $repl =  array('%directory' => $directory, '!htaccess' => '<br />'. nl2br(check_plain($htaccess_lines)));
      form_set_error($form_item, t($message, $repl));
      watchdog('security', $message, $repl, WATCHDOG_ERROR);
    }
  }

  return TRUE;
}

/**
 * Remove a possible leading file directory path from the given path.
 */
function field_file_strip_path($path) {
  $dirpath = file_directory_path();
  $dirlen = strlen($dirpath);
  if (substr($path, 0, $dirlen + 1) == $dirpath .'/') {
    $path = substr($path, $dirlen + 1);
  }
  return $path;
}