<?php
// $Id$

/**
 * @file
 * Enable threaded discussions about general topics.
 */

/**
 * Implementation of hook_help().
 */
function forum_help($section) {

  switch ($section) {

    case 'admin/help#forum':
      $output = '<p>'. t('The forum module lets you create threaded discussion forums for a particular topic on your site. This is similar to a message board system such as phpBB. Forums are very useful because they allow community members to discuss topics with one another, and they are archived for future reference.') .'</p>';
      $output .= '<p>'. t('Forums can be organized under what are called <em>containers</em>. Containers hold forums and, in turn, forums hold threaded discussions. Both containers and forums can be placed inside other containers and forums. By planning the structure of your containers and forums well, you make it easier for users to find a topic area of interest to them.  Forum topics can be moved by selecting a different forum and can be left in the existing forum by selecting <em>leave a shadow copy</em>.  Forum topics can also have their own URL.') .'</p>';
      $output .= '<p>'. t('Forums module <strong>requires Taxonomy and Comments module</strong> be enabled.') .'</p>';
      $output .= t('<p>You can</p>
<ul>
<li>administer forums at <a href="%admin-forum">administer &gt;&gt; forums</a>.</li>
<li>enable the required comment and taxonomy modules at <a href="%admin-modules">administer &gt;&gt; modules</a>.</li>
<li>read about the comment module at <a href="%admin-help-comment">administer &gt;&gt; help &gt;&gt; comment</a>.</li>
<li>read about the taxonomy module at <a href="%admin-help-taxonomy">administer &gt;&gt; help &gt;&gt; taxonomy</a>.</li>
</ul>
', array('%admin-forum' => url('admin/forum'), '%admin-modules' => url('admin/modules'), '%admin-help-comment' => url('admin/help/comment'), '%admin-help-taxonomy' => url('admin/help/taxonomy')));
      $output .= '<p>'. t('For more information please read the configuration and customization handbook <a href="%forum">Forum page</a>.', array('%forum' => 'http://www.drupal.org/handbook/modules/forum/')) .'</p>';
      return $output;
    case 'admin/modules#description':
      return t('Enables threaded discussions about general topics.');

    case 'admin/forum':

      return t('<p>This is a list of existing containers and forums that you can edit. Containers hold forums and, in turn, forums hold threaded discussions. Both containers and forums can be placed inside other containers and forums. By planning the structure of your containers and forums well, you make it easier for users to find a topic area of interest to them.</p>');

    case 'admin/forum/add/container':

      return t('<p>Containers help you organize your forums. The job of a container is to hold, or contain, other forums that are related. For example, a container named "Food" might hold two forums named "Fruit" and "Vegetables".</p>');

    case 'admin/forum/add/forum':

      return t('<p>A forum holds discussion topics that are related. For example, a forum named "Fruit" might contain topics titled "Apples" and "Bananas".</p>');

    case 'admin/forum/configure':
      return t('This is where you can configure system-wide options for how your forums act and display.');

    case 'node/add#forum':

      return t('Create a new topic for discussion in the forums.');

  }
}

/**

 * Implementation of hook_node_info().

 */

function forum_node_info() {

  return array('forum' => array('name' => t('forum topic'), 'base' => 'forum'));

}

/**
 * Implementation of hook_access().
 */

function forum_access($op, $node) {

  global $user;

  if ($op == 'create') {
    return user_access('create forum topics');

  }

  if ($op == 'update' || $op == 'delete') {
    if (user_access('edit own forum topics') && ($user->uid == $node->uid)) {
      return TRUE;
    }
  }

}

/**
 * Implementation of hook_perm().
 */

function forum_perm() {

  return array('create forum topics', 'edit own forum topics', 'administer forums');

}

/**
 * Implementation of hook_nodeapi().
 */
function forum_nodeapi(&$node, $op, $teaser, $page) {
  switch ($op) {
    case 'revision delete':
      db_query('DELETE FROM {forum} WHERE vid = %d', $node->vid);
      break;
  }
}

/**

 * Administration page which allows maintaining forums

 */

function forum_admin() {
  $op = $_POST['op'];
  $edit = $_POST['edit'];

  if (empty($op)) {
    $op = arg(2);
  }

  switch ($op) {
    case 'add':
      if (arg(3) == 'forum') {
        $output = forum_form_forum();
      }
      else if (arg(3) == 'container') {
        $output = forum_form_container();
      }
      break;
    case 'edit':
      if (arg(3) == 'forum') {

        $output = forum_form_forum((array)taxonomy_get_term(arg(4)));

      }
      else if (arg(3) == 'container') {

         $output = forum_form_container((array)taxonomy_get_term(arg(4)));

      }
      break;
    case t('Delete'):
      if (!$edit['confirm']) {

        $output = _forum_confirm_delete($edit['tid']);

        break;
      }
      else {

        $name = $edit['name'];

        $edit['name'] = 0;
      }
    case t('Submit'):

      $status = taxonomy_save_term($edit);

      if (arg(3) == 'container') {

        switch ($status) {
          case SAVED_NEW:
            $containers = variable_get('forum_containers', array());
            $containers[] = $edit['tid'];
            variable_set('forum_containers', $containers);
            drupal_set_message(t('Created new forum container %term.', array('%term' => theme('placeholder', $edit['name']))));
            break;
          case SAVED_UPDATED:
            drupal_set_message(t('The forum container %term has been updated.', array('%term' => theme('placeholder', $edit['name']))));
            break;

          case SAVED_DELETED:

            drupal_set_message(t('The forum container %term has been deleted.', array('%term' => theme('placeholder', $name))));
            break;

        }
      }
      else {

        switch ($status) {
          case SAVED_NEW:
            drupal_set_message(t('Created new forum %term.', array('%term' => theme('placeholder', $edit['name']))));
            break;
          case SAVED_UPDATED:
            drupal_set_message(t('The forum %term has been updated.', array('%term' => theme('placeholder', $edit['name']))));
            break;
          case SAVED_DELETED:
            drupal_set_message(t('The forum %term has been deleted.', array('%term' => theme('placeholder', $name))));
            break;

        }
      }

      drupal_goto('admin/forum');
    default:
      $output = forum_overview();
  }

  return $output;

}

/**
 * Implementation of hook_taxonomy().
 */

function forum_taxonomy($op, $type, $object = NULL) {

  if ($op == 'delete' && $type == 'term' && $object->vid == _forum_get_vid())  {

    $results = db_query('SELECT f.nid FROM {forum} f WHERE f.tid = %d', $object->tid);

    while ($node = db_fetch_object($results)) {

      node_delete($node->nid);

    }

  }

  elseif ($op == 'delete' && $type == 'vocabulary' && $object->vid == _forum_get_vid())  {
    variable_del('forum_nav_vocabulary');
  }

}

/**
 * Returns a confirmation page for deleting a forum taxonomy term
 *
 * @param $tid ID of the term to be deleted
 */

function _forum_confirm_delete($tid) {

  $term = taxonomy_get_term($tid);

  $form['tid'] = array('#type' => 'hidden', '#value' => $tid);

  return confirm_form('forum_confirm_delete', $form, t('Are you sure you want to delete the forum %name?', array('%name' => theme('placeholder', $term->name))),
                  'admin/forums', t('Deleting a forum or container will delete all sub-forums as well. This action cannot be undone.'), t('Delete'), t('Cancel'));

}

/**
 * Returns a form for adding a container to the forum vocabulary
 *
 * @param $edit Associative array containing a container term to be added or edited.
 */
function forum_form_container($edit = array()) {

  $form['name'] = array('#title' => t('Container name'), '#type' => 'textfield', '#default_value' => $edit['name'], '#maxlength' =>  64, '#description' => t('The container name is used to identify related forums.'), '#required' => TRUE);

  $form['description'] = array('#type' => 'textarea', '#title' => t('Description'), '#default_value' => $edit['description'], '#description' => t('The container description can give users more information about the forums it contains.'));

  $form['parent']['#tree'] = TRUE;

  $form['parent'][0] = _forum_parent_select($edit['tid'], t('Parent'), 'container');

  $form['weight'] = array('#type' => 'weight', '#title' => t('Weight'), '#default_value' => $edit['weight'], '#description' => t('When listing containers, those with with light (small) weights get listed before containers with heavier (larger) weights. Containers with equal weights are sorted alphabetically.'));

  $form['vid'] = array('#type' => 'hidden', '#value' => _forum_get_vid());
  $form['submit'] = array('#type' => 'submit', '#value' => t('Submit'));

  if ($edit['tid']) {

    $form['delete'] = array('#type' => 'submit', '#value' => t('Delete'));
    $form['tid'] = array('#type' => 'hidden', '#value' => $edit['tid']);

  }

  return drupal_get_form('forum_form_container', $form);

}

/**
 * Returns a form for adding a forum to the forum vocabulary
 *
 * @param $edit Associative array containing a forum term to be added or edited.
 */
function forum_form_forum($edit = array()) {

  $form['name'] = array('#type' => 'textfield', '#title' => t('Forum name'), '#default_value' => $edit['name'], '#maxlength' =>  64, '#description' => t('The forum name is used to identify related discussions.'), '#required' => TRUE);

  $form['description'] = array('#type' => 'textarea', '#title' => t('Description'), '#default_value' => $edit['description'], '#description' => t('The forum description can give users more information about the discussion topics it contains.'));

  $form['parent']['#tree'] = TRUE;

  $form['parent'][0] = _forum_parent_select($edit['tid'], t('Parent'), 'forum');

  $form['weight'] = array('#type' => 'weight', '#title' => t('Weight'), '#default_value' => $edit['weight'], '#description' => t('When listing forums, those with with light (small) weights get listed before containers with heavier (larger) weights. Forums with equal weights are sorted alphabetically.'));

  $form['vid'] = array('#type' => 'hidden', '#value' => _forum_get_vid());
  $form['submit' ] = array('#type' => 'submit', '#value' => t('Submit'));

  if ($edit['tid']) {

    $form['delete'] = array('#type' => 'submit', '#value' => t('Delete'));
    $form['tid'] = array('#type' => 'hidden', '#value' => $edit['tid']);

  }

  return drupal_get_form('forum_form_forum', $form);

}

/**
 * Returns a select box for available parent terms
 *
 * @param $tid ID of the term which is being added or edited
 * @param $title Title to display the select box with

 * @param $child_type Whether the child is forum or container

 */

function _forum_parent_select($tid, $title, $child_type) {

  $parents = taxonomy_get_parents($tid);

  if ($parents) {
    $parent = array_shift($parents);
    $parent = $parent->tid;
  }
  else {
    $parent = 0;
  }

  $children = taxonomy_get_tree(_forum_get_vid(), $tid);

  // A term can't be the child of itself, nor of its children.
  foreach ($children as $child) {
    $exclude[] = $child->tid;
  }
  $exclude[] = $tid;

  $tree = taxonomy_get_tree(_forum_get_vid());
  $options[0] = '<'. t('root') .'>';
  if ($tree) {
    foreach ($tree as $term) {
      if (!in_array($term->tid, $exclude)) {

        $options[$term->tid] = _taxonomy_depth($term->depth) . $term->name;

      }

    }
  }

  if ($child_type == 'container') {
    $description = t('Containers are usually placed at the top (root) level of your forum but you can also place a container inside a parent container or forum.');
  }
  else if ($child_type == 'forum') {
    $description = t('You may place your forum inside a parent container or forum, or at the top (root) level of your forum.');
  }

  return array('#type' => 'select', '#title' => $title, '#default_value' => $parent, '#options' => $options, '#description' => $description, '#required' => TRUE);

}

/**

 * Returns an overview list of existing forums and containers

 */

function forum_overview() {
  $header = array(t('Name'), t('Operations'));

  $tree = taxonomy_get_tree(_forum_get_vid());
  if ($tree) {
    foreach ($tree as $term) {
      if (in_array($term->tid, variable_get('forum_containers', array()))) {

        $rows[] = array(_taxonomy_depth($term->depth) .' '. check_plain($term->name), l(t('edit container'), "admin/forum/edit/container/$term->tid"));

      }
      else {

        $rows[] = array(_taxonomy_depth($term->depth) .' '. check_plain($term->name), l(t('edit forum'), "admin/forum/edit/forum/$term->tid"));

       }

    }
  }

  else {

    $rows[] = array(array('data' => '<em>' . t('There are no existing containers or forums. You may add some on the <a href="%container">add container</a> or <a href="%forum">add forum</a> pages.', array('%container' => url('admin/forum/add/container'), '%forum' => url('admin/forum/add/forum'))) . '</em>', 'colspan' => 2));

  }
  return theme('table', $header, $rows);

}

/**
 * Returns the vocabulary id for forum navigation.
 */
function _forum_get_vid() {
  $vid = variable_get('forum_nav_vocabulary', '');
  if (empty($vid)) {
    // Check to see if a forum vocabulary exists

    $vid = db_result(db_query("SELECT vid FROM {vocabulary} WHERE module = '%s'", 'forum'));

    if (!$vid) {

      $edit = array('name' => 'Forums', 'multiple' => 0, 'required' => 1, 'hierarchy' => 1, 'relations' => 0, 'module' => 'forum', 'nodes' => array('forum' => 1));

      taxonomy_save_vocabulary($edit);
      $vid = $edit['vid'];

    }
    variable_set('forum_nav_vocabulary', $vid);
  }

  return $vid;
}

/**
 * Implementation of hook_settings
 */

function forum_admin_configure() {

  $form = array();

  $number = drupal_map_assoc(array(5, 10, 15, 20, 25, 30, 35, 40, 50, 60, 80, 100, 10000));

  $form['forum_hot_topic'] = array('#type' => 'select', '#title' => t('Hot topic threshold'), '#default_value' => variable_get('forum_hot_topic', 15), '#options' => $number, '#description' => t('The number of posts a topic must have to be considered hot.'));

  $number = drupal_map_assoc(array(10, 25, 50, 75, 100));

  $form['forum_per_page'] = array('#type' => 'select', '#title' => t('Topics per page'), '#default_value' => variable_get('forum_per_page', 25), '#options' => $number, '#description' => t('The default number of topics displayed per page; links to browse older messages are automatically being displayed.'));

  $forder = array(1 => t('Date - newest first'), 2 => t('Date - oldest first'), 3 => t('Posts - most active first'), 4=> t('Posts - least active first'));

  $form['forum_order'] = array('#type' => 'radios', '#title' => t('Default order'), '#default_value' => variable_get('forum_order', '1'), '#options' => $forder, '#description' => t('The default display order for topics.'));

  return system_settings_form('forum_admin_configure', $form);

}

/**
 * Implementation of hook_load().
 */

function forum_load($node) {

  $forum = db_fetch_object(db_query('SELECT * FROM {forum} WHERE vid = %d', $node->vid));

  return $forum;
}

/**
 * Implementation of hook_block().
 *
 * Generates a block containing the currently active forum topics and the
 * most recently added forum topics.
 */

function forum_block($op = 'list', $delta = 0, $edit = array()) {
  switch ($op) {
    case 'list':

      $blocks[0]['info'] = t('Active forum topics');
      $blocks[1]['info'] = t('New forum topics');

      return $blocks;

    case 'configure':

      $form['forum_block_num_'. $delta] = array('#type' => 'select', '#title' => t('Number of topics'), '#default_value' => variable_get('forum_block_num_'. $delta, '5'), '#options' => drupal_map_assoc(array(2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)));

      return $form;

    case 'save':

      variable_set('forum_block_num_'. $delta, $edit['forum_block_num_'. $delta]);

      break;

    case 'view':
      if (user_access('access content')) {

        switch ($delta) {
          case 0:

            $title = t('Active forum topics');

            $sql = db_rewrite_sql("SELECT n.nid, n.title, l.last_comment_timestamp, l.comment_count FROM {node} n INNER JOIN {node_comment_statistics} l ON n.nid = l.nid WHERE n.status = 1 AND n.type = 'forum' ORDER BY l.last_comment_timestamp DESC");

            $result = db_query_range($sql, 0, variable_get('forum_block_num_0', '5'));
            if (db_num_rows($result)) {
              $content = node_title_list($result);
            }

            break;

          case 1:

            $title = t('New forum topics');
            $sql = db_rewrite_sql("SELECT n.nid, n.title, l.comment_count FROM {node} n INNER JOIN {node_comment_statistics} l ON n.nid = l.nid WHERE n.type = 'forum' AND n.status = 1 ORDER BY n.nid DESC");

            $result = db_query_range($sql, 0, variable_get('forum_block_num_1', '5'));
            if (db_num_rows($result)) {
              $content = node_title_list($result);
            }

            break;

        }

        if ($content) {

          $content .= '<div class="more-link">'. l(t('more'), 'forum', array('title' => t('Read the latest forum topics.'))) .'</div>';

        }

        $block['subject'] = $title;

        $block['content'] = $content;

        return $block;
      }
  }

}

/**
 * Implementation of hook_link().
 */

function forum_link($type, $node = 0, $main = 0) {

  global $user;

  $links = array();

  if (!$main && $type == 'node' && $node->type == 'forum') {

    // get previous and next topic

    $sql = "SELECT n.nid, n.title, n.sticky, l.comment_count, l.last_comment_timestamp FROM {node} n INNER JOIN {node_comment_statistics} l ON n.nid = l.nid INNER JOIN {term_node} r ON n.nid = r.nid AND r.tid = %d WHERE n.status = 1 AND n.type = 'forum' ORDER BY n.sticky DESC, ". _forum_get_topic_order_sql(variable_get('forum_order', 1));

    $sql = db_rewrite_sql($sql);

    $result = db_query($sql, $node->tid);

    while ($topic = db_fetch_object($result)) {
      if ($stop == 1) {

        $next = new StdClass();

        $next->nid = $topic->nid;
        $next->title = $topic->title;
        break;
      }
      if ($topic->nid == $node->nid) {
        $stop = 1;
      }
      else {

        $prev = new StdClass();

        $prev->nid = $topic->nid;
        $prev->title = $topic->title;
      }
    }

    if ($prev) {

      $links[] = l(t('previous forum topic'), "node/$prev->nid", array('title' => check_plain($prev->title)));

    }

    if ($next) {

      $links[] = l(t('next forum topic'), "node/$next->nid", array('title' => check_plain($next->title)));

    }

  }

  return $links;

}

function forum_term_path($term) {
  return 'forum/'. $term->tid;
}

/**
 * Implementation of hook_menu().
 */

function forum_menu($may_cache) {

  $items = array();

  if ($may_cache) {
    $items[] = array('path' => 'node/add/forum', 'title' => t('forum topic'),
      'access' => user_access('create forum topics'));

    $items[] = array('path' => 'forum', 'title' => t('forums'),
      'callback' => 'forum_page',
      'access' => user_access('access content'),

      'type' => MENU_SUGGESTED_ITEM);

    $items[] = array('path' => 'admin/forum', 'title' => t('forums'),
      'callback' => 'forum_admin',
      'access' => user_access('administer forums'),
      'type' => MENU_NORMAL_ITEM);

    $items[] = array('path' => 'admin/forum/list', 'title' => t('list'),
      'access' => user_access('administer forums'),
      'type' => MENU_DEFAULT_LOCAL_TASK, 'weight' => -10);
    $items[] = array('path' => 'admin/forum/add/container', 'title' => t('add container'),
      'access' => user_access('administer forums'),
      'type' => MENU_LOCAL_TASK);
    $items[] = array('path' => 'admin/forum/add/forum', 'title' => t('add forum'),
      'access' => user_access('administer forums'),
      'type' => MENU_LOCAL_TASK);

    $items[] = array('path' => 'admin/forum/configure', 'title' => t('configure'),
      'callback' => 'forum_admin_configure',
      'access' => user_access('administer forums'),
      'type' => MENU_LOCAL_TASK);

    $items[] = array('path' => 'admin/forum/edit/container', 'title' => t('edit container'),
      'access' => user_access('administer forums'),
      'type' => MENU_CALLBACK);
    $items[] = array('path' => 'admin/forum/edit/forum', 'title' => t('edit forum'),
      'access' => user_access('administer forums'),
      'type' => MENU_CALLBACK);

  }

  return $items;
}