<?php
// $Id: project_legacy_paths.module,v 1.2 2010-07-08 23:16:17 dww Exp $

/**
 * @file Redirect project browsing paths from the Drupal 5 form to the Drupal 6 form.
 */

function project_legacy_paths_menu(){
  $items = array();

  // Project browsing pages
  if (project_use_taxonomy()) {
    $items['project/%project_legacy_paths_top_level_term/%'] = array(
      'access callback' => TRUE,
      'page callback' => 'project_legacy_paths_page_callback',
      'page arguments' => array(1, 2),
    );
    $items['project/%project_legacy_paths_top_level_term/%/%'] = array(
      'access callback' => TRUE,
      'page callback' => 'project_legacy_paths_page_callback',
      'page arguments' => array(1, 2, 3),
    );
  }
  return $items;
}

/**
 * Menu load function for project type top level terms (eg. modules, themes, etc.).
 */
function project_legacy_paths_top_level_term_load($term_name) {
  $project_type_vid = _project_get_vid();
  if (empty($project_type_vid)) {
    return FALSE;
  }

  $db_result = db_query(db_rewrite_sql("SELECT * FROM {term_data} t INNER JOIN {term_hierarchy} th ON t.tid = th.tid WHERE LOWER(t.name) = LOWER('%s') AND th.parent = 0 AND t.vid = %d", 't', 'tid'), trim($term_name), $project_type_vid);
  $result = array();
  while ($term = db_fetch_object($db_result)) {
    $result[] = $term;
  }
  if (!empty($result)) {
    return $result[0];
  }
  else {
    return FALSE;
  }
}

/**
 * Implementation of hook_project_sort_methods().
 *
 * The code in this function is the (slightly modified) relevant piece of code
 * from the project_project_sort_methods() function in the Drupal 5 version
 * of the project module.  This code is here because the Drupal 6
 * version of the project module no longer contains this function.
 */
function project_legacy_paths_project_sort_methods($op, $method = NULL) {
  if ($op == 'methods') {
    $methods = array();
    $methods['name'] = 'project';
    $methods['date'] = 'project';
    // The D5 version put the next line within an if (project_use_taxonomy())
    // block, but since we're already checking for that in
    // project_legacy_paths_menu() there is no need to check again.
    $methods['category'] = 'project';
    return $methods;
  }
}

/**
 * Validate the arguments to see if they would have lead to an actual page
 * in the Drupal 5 version of the project module.  If not, the user
 * will be given a page not found error.  Otherwise, determine what the D6
 * URL would be and redirect the user there.
 */
function project_legacy_paths_page_callback($top_level_term, $sort_method = NULL, $category_tid = NULL) {
  // Validate $sort_method.
  $sort_methods = module_invoke_all('project_sort_methods', 'methods');
  if (!empty($sort_methods) && !empty($sort_method)) {
    if (!array_key_exists($sort_method, $sort_methods)) {
      return MENU_NOT_FOUND;
    }
  }
  else {
    return MENU_NOT_FOUND;
  }

  // Validate $category_tid.
  if (isset($category_tid)) {
    if (!is_numeric($category_tid)) {
      return MENU_NOT_FOUND;
    }
    
    // Since 'category' is the only sorting method that uses $category_tid, make
    // sure the sort method is 'category'.
    if ($sort_method != 'category') {
      return MENU_NOT_FOUND;
    }

    // Determine if $category_tid has $top_level_term as its parent.
    if (!db_result(db_query(db_rewrite_sql("SELECT t.tid FROM {term_data} t INNER JOIN {term_hierarchy} th ON t.tid = th.tid WHERE t.tid = %d AND th.parent = %d", 't', 'tid'), $category_tid, $top_level_term->tid))) {
      return MENU_NOT_FOUND;
    }
  }

  // At this point we know that all of the parameters to this function
  // are valid and would have returned a page in the D5 version of project.
  // Now, we just need to redirect to the appropriate URL.

  // @TODO: Below are several variables which we should not hard code.
  // We need to figure out how exactly we want to do this.  Perhaps put the code
  // below in a separate hook function or something.
  $base = 'project';
  $sort_by_identifier = 'sort_by';
  $project_type_term_identifier = 'type';

  $base_path = $base . '/' . strtolower($top_level_term->name);
  
  // Build an array with query key/value properties.
  $query = array();
  if ($sort_method == 'date') {
    $query[$sort_by_identifier] = 'changed';
  }
  elseif ($sort_method == 'name') {
    $query[$sort_by_identifier] = 'title';
  }
  elseif ($sort_method == 'category') {
    $query[$project_type_term_identifier] = $category_tid;
  }
  drupal_goto($base_path, $query, NULL, 301);
}