<?php
// $Id: cvs_deploy.module,v 1.29 2010-10-02 23:52:23 dww Exp $

/**
 * @file
 *
 * This module improves the administrative UI for sites that are deployed
 * directly via a CVS workspace (as opposed to sites built from packaged
 * releases that are downloaded from drupal.org).
 *
 * See the README.txt file for more information.
 *
 * @author Derek Wright ("dww") http://drupal.org/user/46549
 */

/**
 * Returns the human-readable version string from a given CVS tag.
 */
function cvs_deploy_version_from_tag($tag) {
  // If there's nothing, it must be a HEAD checkout, and therefore,
  // we have no idea what the version is.
  $version = '';
  $match = array();
  if (empty($tag) || $tag == 'HEAD') {
    $version = 'HEAD';
  }
  // See if it's a full, official release from a tag:
  elseif (preg_match('@^DRUPAL-(\d+)--(\d+)-(\d+)(-.+)?@', $tag, $match)) {
    $version = $match[1] .'.x-'. $match[2] .'.'. $match[3];
    if (isset($match[4])) {
      // This version's tag has 'extra', so clean that up.
      $version .= '-'. preg_replace('/[_-]/', '', strtolower($match[4]));
    }
  }
  // If not, see if it's from a branch (like a development snapshot).
  elseif (preg_match('@^DRUPAL-(\d+)(--(\d+))?@', $tag, $match)) {
    $version = $match[1] .'.x-'. (isset($match[3]) ? $match[3] : '1') .'.x-dev';
  }
  return $version;
}

/**
 * Implements hook_system_info_alter().
 */
function cvs_deploy_system_info_alter(&$info, $file, $type) {
  // First, if we don't know the 'project' attribute, fill it in based on the
  // CVS/Repository file.
  if (empty($info['project'])) {
    $info['project'] = cvs_deploy_get_project_name($file);
  }

  // Now, alter the version string based on the CVS sticky tag.
  if (empty($info['version'])) {
    $info['version'] = '';
  }
  _cvs_deploy_version_alter($info['version'], $file);

  // Find the timestamp for the most recently modified CVS/Entries file.
  $mtime = _cvs_deploy_find_latest_update(dirname($file->uri), 0);

  // Only fill this in if the .info file does not define a 'datestamp'.
  if (empty($info['datestamp'])) {
    $info['datestamp'] = $mtime;
  }

  // However, the '_info_file_ctime' should always get the latest value.
  if (empty($info['_info_file_ctime'])) {
    $info['_info_file_ctime'] = $mtime;
  }
  else {
    $info['_info_file_ctime'] = max($info['_info_file_ctime'], $mtime);
  }
}

/**
 * Private helper to alter the version of a module based on what we can figure
 * out about the CVS tag in use.
 */
function _cvs_deploy_version_alter(&$version, $file) {
  static $available = array();
  $match = array();
  if (empty($version)) {
    // The .info file contains no version data. Find the version based
    // on the sticky tag in the local workspace (the CVS/Tag file).
    $cvs_dir = dirname($file->uri) .'/CVS';
    if (is_dir($cvs_dir)) {
      $tag = '';  // If there's no Tag file, there's no tag, a.k.a. HEAD.
      if (file_exists($cvs_dir .'/Tag')) {
        $tag_file = trim(file_get_contents($cvs_dir .'/Tag'));
        if ($tag_file) {
          // Get the sticky tag for this workspace: strip off the leading 'T'.
          $tag = preg_replace('@^(T|N)@', '', $tag_file);
        }
      }
      $version = cvs_deploy_version_from_tag($tag);
    }
  }
  // The weird concatenation prevents CVS from 'expanding' this $Name.
  elseif (preg_match('/\$'.'Name: (.*?)\$/', $version, $match)) {
    $version = cvs_deploy_version_from_tag(trim($match[1]));
  }

  if (module_exists('update') && $version == 'HEAD') {
    module_load_include('inc', 'update', 'update.compare');
    // If there's available update_status data, we can use the version string
    // the release node pointing to HEAD really has. However, we can only
    // safely grab this data directly from the cache, since if we call
    // update_get_available() here, we'd enter infinite recursion when that
    // function invokes update_get_projects(), which in turn needs to process
    // the .info files, which invokes the hook that leads here.
    if (empty($available)) {
      $available = _update_get_cached_available_releases();
    }
    $project = update_get_project_name($file);
    if (isset($available[$project]['releases'])) {
      foreach ($available[$project]['releases'] as $release) {
        if (isset($release['tag']) && $release['tag'] == 'HEAD') {
          $version = $release['version'];
          break;
        }
      }
    }
  }
}

/**
 * Private helper to alter the 'project' of a module based on what directory
 * in the CVS repository the module has been checked out from.
 */
function cvs_deploy_get_project_name($file) {
  static $projects = array();
  $name = $file->name;
  if (empty($projects[$name])) {
    // TODO: cache this in {cache}, too?
    $cvs_dir = dirname($file->uri) .'/CVS';
    if (is_dir($cvs_dir)) {
      $repository = '';
      if (file_exists($cvs_dir .'/Repository')) {
        $repo_file = trim(file_get_contents($cvs_dir .'/Repository'));
        if ($repo_file) {
          $parts = explode('/', $repo_file);
          if ($parts[0] == 'drupal') {
            $projects[$name] = $parts[0];
          }
          else {
            $projects[$name] = $parts[2];
          }
        }
      }
    }
  }
  return (isset($projects[$name]) ? $projects[$name] : '');
}

/**
 * Recursive helper function to find the latest modification time on every
 * CVS/Entires file in the current directory tree.
 *
 * @param $dir
 *   The directory to search.
 * @param $timestamp
 *   The current latest modification timestamp on any CVS/Entries file.
 * @return
 *   The latest mtime based on what we learned in the current directory.
 */
function _cvs_deploy_find_latest_update($dir, $timestamp) {
  if (is_dir($dir)) {
    $fp = opendir($dir);
    while (FALSE !== ($file = readdir($fp))) {
      if ($file == '.' || $file == '..') {
        continue;
      }
      if ($file == 'CVS' && is_dir("$dir/CVS")) {
        $entries_file = $dir .'/CVS/Entries';
        if (file_exists($entries_file)) {
          $mtime = filemtime($entries_file);
          $timestamp = ($mtime > $timestamp) ? $mtime : $timestamp;
        }
      }
      elseif (is_dir("$dir/$file")) {
        $timestamp = _cvs_deploy_find_latest_update("$dir/$file", $timestamp);
      }
    }
    closedir($fp);
  }
  return $timestamp;
}

/**
 * Implements hook_update_status_alter().
 *
 * If we're viewing the available updates report, and any of the projects on
 * the page still think their version is just 'HEAD', but the project has
 * release data for a release node using 'HEAD' as the tag, we're in the edge
 * case of viewing the report when there was initially no available update
 * data. In that case, when hook_system_info_alter() was first invoked, we
 * didn't have any cached data, and we therefore couldn't convert the version
 * from HEAD into something else. So, Update status is going to think this
 * version is not supported, since it doesn't know what version you're
 * actually running and couldn't find any release information that matched
 * what you've got. So, if we hit a case like this, redirect to the available
 * updates report so that there are no bogus results displayed.
 */
function cvs_deploy_update_status_alter($projects) {
  if ($_GET['q'] == 'admin/reports/updates') {
    foreach ($projects as $key => $project) {
      if (isset($project['existing_version']) && $project['existing_version'] == 'HEAD' && !empty($project['releases'])) {
        foreach ($project['releases'] as $version => $release) {
          if ($release['tag'] == 'HEAD') {
            return drupal_goto('admin/reports/updates');
          }
        }
      }
    }
  }
}