<?php

/**
 * @file
 * The Hacked! module, shows which project have been changed since download.
 *
 * We download the original project file, and hash all the files contained
 * within, then we hash our local copies and compare.
 * This module should never be used on a production server.
 */

define('HACKED_CACHE_TABLE', 'cache_hacked');

define('HACKED_STATUS_UNCHECKED', 1);
define('HACKED_STATUS_PERMISSION_DENIED', 2);
define('HACKED_STATUS_HACKED', 3);
define('HACKED_STATUS_DELETED', 4);
define('HACKED_STATUS_UNHACKED', 5);

define('HACKED_DEFAULT_FILE_HASHER', 'hacked_ignore_line_endings');

if (function_exists('hacked_menu')) {
  return;
}

/**
 * Implementation of hook_menu().
 */
function hacked_menu() {
  $items = array();

  $items['admin/reports/hacked'] = array(
    'title' => 'Hacked',
    'description' => 'Get a code hacking report about your installed modules and themes.',
    'page callback' => 'hacked_reports_hacked',
    'access arguments' => array('administer site configuration'),
    'weight' => 10,
    'file' => 'hacked.report.inc',
  );

  $items['admin/reports/hacked/settings'] = array(
    'title' => 'Settings',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('hacked_settings_form'),
    'access arguments' => array('administer site configuration'),
    'file' => 'hacked.admin.inc',
    'type' => MENU_LOCAL_TASK,
  );

  $items['admin/reports/hacked/list'] = array(
    'title' => 'List projects',
    'type' => MENU_DEFAULT_LOCAL_TASK,
  );

  $items['admin/reports/hacked/rebuild-report'] = array(
    'type' => MENU_CALLBACK,
    'page callback' => 'hacked_reports_rebuild',
    'access arguments' => array('administer site configuration'),
    'file' => 'hacked.report.inc',
  );

  $items['admin/reports/hacked/%hacked_project'] = array(
    'title callback' => 'hacked_reports_hacked_details_title',
    'title arguments' => array(3),
    'page callback' => 'hacked_reports_hacked_details',
    'page arguments' => array(3),
    'access arguments' => array('administer site configuration'),
    'type' => MENU_CALLBACK,
    'file' => 'hacked.details.inc',
  );

  if (module_exists('diff')) {
    $items['admin/reports/hacked/%hacked_project/diff/%menu_tail'] = array(
      'title callback' => 'hacked_reports_hacked_diff_title',
      'title arguments' => array(3, 5),
      'load arguments'   => array('%map', '%index'),
      'page callback' => 'hacked_reports_hacked_diff',
      'page arguments' => array(3, 5),
      'access arguments' => array('view diffs of changed files'),
      'type' => MENU_CALLBACK,
      'file' => 'hacked.diff.inc',
    );
  }

  return $items;
}

/**
 * Menu loader for loading a project from its short name.
 *
 * In this function we call the calculate function both the update module and
 * our hacked module. This may mean we return FALSE when there is no internet
 * connection.
 *
 * @param $short_name
 *   The short name of the project to load.
 * @param $ensure_downloaded
 *   Should the project be downloaded to the local cache.
 */
function hacked_project_load($short_name) {
  return new hackedProject($short_name);
}

/**
 * Menu title callback for the hacked details page.
 */
function hacked_reports_hacked_details_title($project) {
  return t('Hacked status for @project', array('@project' => $project->title()));
}

/**
 * Menu title callback for the hacked site report page.
 */
function hacked_reports_hacked_diff_title($project, $file) {
  return t('Hacked status for file @file in project @project', array('@project' => $project->title(), '@file' => $file));
}

/**
 * Implementation of hook_flush_caches().
 */
function hacked_flush_caches() {
  return array(HACKED_CACHE_TABLE);
}

/**
 * Implementation of the hook_theme() registry.
 */
function hacked_theme() {
  return array(
    'hacked_report' => array(
      'arguments' => array('data' => NULL),
      'file' => 'hacked.theme.inc',
    ),
    'hacked_detailed_report' => array(
      'arguments' => array('project' => NULL),
      'file' => 'hacked.details.inc',
    ),
  );
}

/**
 * Implementation of hook_permission().
 */
function hacked_permission() {
  return array(
    'view diffs of changed files' => array(
      'title' => t('View diffs of changed files'),
      'restrict access' => TRUE,
    ),
  );
}

/**
 * Compute the report data for hacked.
 *
 * WARNING: This function can invoke a batch process and end your current page.
 * So you'll want to be very careful if you call this!
 */
function hacked_calculate_project_data($projects, $force = FALSE, $redirect = NULL) {
  // Try to get the report form cache if we can.
  $cache = cache_get('hacked:full-report', HACKED_CACHE_TABLE);
  if (!empty($cache->data) && !$force) {
    return $cache->data;
  }

  // Enter a batch to build the report.
  $operations = array();
  foreach ($projects as $project) {
    $operations[] = array(
      'hacked_build_report_batch',
      array($project['name']),
    );
  }

  $batch = array(
    'operations' => $operations,
    'finished' => 'hacked_build_report_batch_finished',
    'file' => drupal_get_path('module', 'hacked') . '/hacked.report.inc',
    'title' => t('Building report'),
  );

  batch_set($batch);
  // End page execution and run the batch.
  batch_process($redirect);
}

/**
 * Sort callback for sorting the projects in the report.
 */
function _hacked_project_report_sort_by_status($a, $b) {
  if ($a['status'] == $b['status']) {
    return strcmp($a['name'], $b['name']);
  }
  else {
    return $a['status'] - $b['status'];
  }
}

/**
 * Determine if a file is a binary file.
 *
 * Taken from: http://www.ultrashock.com/forums/server-side/checking-if-a-file-is-binary-98391.html
 * and then tweaked in: http://drupal.org/node/760362.
 */
function hacked_file_is_binary($file) {
  if (file_exists($file)) {
    if (!is_file($file)) return 0;
    if (!is_readable($file)) return 1;

    $fh  = fopen($file, "r");
    $blk = fread($fh, 512);
    fclose($fh);
    clearstatcache();

    return (
      0 or substr_count($blk, "^\r\n") / 512 > 0.3
        or substr_count($blk, "^ -~") / 512 > 0.3
        or substr_count($blk, "\x00") > 0
    );
  }
  return 0;
}


/**
 * Hacked! version of the core function, can return hidden files too.
 *
 * @see file_scan_directory().
 */
function hacked_file_scan_directory($dir, $mask, $nomask = array('.', '..', 'CVS'), $callback = 0, $recurse = TRUE, $key = 'filename', $min_depth = 0, $depth = 0) {
  $key = (in_array($key, array('filename', 'basename', 'name')) ? $key : 'filename');
  $files = array();

  if (is_dir($dir) && $handle = opendir($dir)) {
    while (FALSE !== ($file = readdir($handle))) {
      if (!in_array($file, $nomask)) {
        if (is_dir("$dir/$file") && $recurse) {
          // Give priority to files in this folder by merging them in after any subdirectory files.
          $files = array_merge(hacked_file_scan_directory("$dir/$file", $mask, $nomask, $callback, $recurse, $key, $min_depth, $depth + 1), $files);
        }
        elseif ($depth >= $min_depth && preg_match($mask, $file)) {
          // Always use this match over anything already set in $files with the same $$key.
          $filename = "$dir/$file";
          $basename = basename($file);
          $name = substr($basename, 0, strrpos($basename, '.'));
          $files[$$key] = new stdClass();
          $files[$$key]->filename = $filename;
          $files[$$key]->basename = $basename;
          $files[$$key]->name = $name;
          if (is_callable($callback)) {
            $callback($filename);
          }
        }
      }
    }

    closedir($handle);
  }

  return $files;
}

/**
 * Returns the version of the installed cvs executable on this machine
 */
function hacked_cvs_executable_get_version() {
  $cvs_cmd = hacked_cvs_get_command();
  // Run exec looking for the command:
  $output_lines = array();
  $return_value = 1;
  exec("$cvs_cmd --version", $output_lines, $return_value);
  if ($return_value === 0) {
    // We executed correctly, go looking for the version line:
    $version = 'Concurrent Versions System (CVS)';
    if (is_array($output_lines)) {
      foreach ($output_lines as $line) {
        if (strpos($line, 'CVS')) {
          $version = $line;
          break;
        }
      }
    }
    return $version;
  }
  else {
    return FALSE;
  }
}

/**
 * Will return TRUE if the CVS functions should be enabled.
 */
function hacked_cvs_enabled() {
  $cvs_enabled = &drupal_static(__FUNCTION__);
  if (is_null($cvs_enabled)) {
    $cvs_enabled = module_exists('cvs_deploy') && (bool)hacked_cvs_executable_get_version();
  }
  return $cvs_enabled;
}

/**
 * Helper function to return the command to run cvs on the command line.
 */
function hacked_cvs_get_command() {
  $cvs_cmd = variable_get('hacked_cvs_cmd', 'cvs');
  return $cvs_cmd;
}

/**
 * Checks out a folder from CVS to a temporary directory.
 *
 * @param $cvsroot
 *   The CVSROOT of the folder to check out.
 * @param $folder
 *   The module to check out from CVS.
 * @param $checkout_location
 *   The location in which to place the checkout.
 * @param $tag
 *   The tag to checkout, defaults to 'HEAD'.
 * @return
 *   Either FALSE on failure or the location of the checked out files.
 */
function hacked_cvs_checkout($cvsroot, $folder, $checkout_location, $checkout_folder, $tag = 'HEAD') {
  $cvs_cmd = hacked_cvs_get_command();
  $t = $checkout_location . '/' . $checkout_folder;
  file_prepare_directory($checkout_location, FILE_CREATE_DIRECTORY);
  file_prepare_directory($t, FILE_CREATE_DIRECTORY);

  exec("cd $checkout_location; $cvs_cmd -z6 -d$cvsroot -q checkout -d $checkout_folder -r $tag $folder", $output_lines, $return_value);

  if ($return_value == 0) {
    return $t;
  }

  return FALSE;
}

/**
 * Return the file hasher that is currently selected by the user.
 */
function hacked_get_file_hasher($name = NULL) {
  if (is_null($name)) {
    $name = variable_get('hacked_selected_file_hasher', HACKED_DEFAULT_FILE_HASHER);
  }
  if (!module_exists('hacked')) {
    $hashers = hacked_hacked_file_hashers_info();
  }
  else {
    $hashers = hacked_get_file_hashers();
  }
  $class_name = $hashers[$name]['class'];
  return new $class_name;
}

/**
 * Gets all the file hashers defined.
 */
function hacked_get_file_hashers() {
  $hashers = &drupal_static(__FUNCTION__);
  if (is_null($hashers)) {
    $hashers = module_invoke_all('hacked_file_hashers_info');
    drupal_alter('hacked_file_hashers_info', $hashers);
  }
  return $hashers;
}

/**
 * Implements hook_hacked_file_hashers_info().
 */
function hacked_hacked_file_hashers_info() {
  $hashers = array();

  $hashers['hacked_ignore_line_endings'] = array(
    'class' => 'hackedFileIgnoreEndingsHasher',
    'name' => t('Ignore line endings'),
    'description' => t('When hashing files differences in line endings will be ignored. This might be useful if projects have been edited on a different platform than of the original author\'s. E.g. if a file has been opened and saved on Windows.'),
  );

  $hashers['hacked_include_line_endings'] = array(
    'class' => 'hackedFileIncludeEndingsHasher',
    'name' => t('Include line endings'),
    'description' => t('When hashing files differences in line endings will be included.'),
  );

  return $hashers;
}