<?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 .= '<p>'. t('For more information please read the configuration and customization handbook <a href="@forum">Forum page</a>.', array('@forum' => 'http://drupal.org/handbook/modules/forum/')) .'</p>';

      return $output;

    case 'admin/content/forum':

      return '<p>'. t('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/content/forum/add/container':

      return '<p>'. t('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/content/forum/add/forum':

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

    case 'admin/content/forum/settings':
      return '<p>'. t('These settings provide the ability to fine tune the display of your forum topics.') .'</p>';

  }
}

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

function forum_menu() {
  $items['node/add/forum'] = array(
    'title' => t('Forum topic'),
    'access arguments' => array('create forum topics'),
  );
  $items['forum'] = array(
    'title' => t('Forums'),
    'page callback' => 'forum_page',
    'access arguments' => array('access content'),
    'type' => MENU_SUGGESTED_ITEM,
  );
  $items['admin/content/forum'] = array(
    'title' => t('Forums'),
    'description' => t('Control forums and their hierarchy and change forum settings.'),
    'page callback' => 'forum_overview',
    'access arguments' => array('administer forums'),
  );
  $items['admin/content/forum/list'] = array(
    'title' => t('List'),
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => -10,
  );
  $items['admin/content/forum/add/container'] = array(
    'title' => t('Add container'),
    'page callback' => 'forum_form_main',
    'page arguments' => array('container'),
    'type' => MENU_LOCAL_TASK,

    'parent' => 'admin/content/forum',

  );
  $items['admin/content/forum/add/forum'] = array(
    'title' => t('Add forum'),
    'page callback' => 'forum_form_main',
    'page arguments' => array('forum'),
    'type' => MENU_LOCAL_TASK,

    'parent' => 'admin/content/forum',

  );
  $items['admin/content/forum/settings'] = array(
    'title' => t('Settings'),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('forum_admin_settings'),
    'weight' => 5,
    'type' => MENU_LOCAL_TASK,

    'parent' => 'admin/content/forum',

  );
  $items['admin/content/forum/edit'] = array(
    'page callback' => 'forum_form_main',
    'map arguments' => array('_forum_get_term', 5, array()),
    'type' => MENU_CALLBACK,
  );
  $items['admin/content/forum/edit/container/%'] = array(
    'title' => t('Edit container'),
    'page arguments' => array('container', 5),
  );
  $items['admin/content/forum/edit/forum/%'] = array(
    'title' => t('Edit forum'),
    'page callback' => 'forum_form_main',
    'page arguments' => array('forum', 5),
  );
  return $items;
}

function forum_init() {
  drupal_add_css(drupal_get_path('module', 'forum') .'/forum.css');
}

function _forum_get_term($tid) {
  return (array)taxonomy_get_term($tid);

}

/**

 * Implementation of hook_node_info().

 */

function forum_node_info() {

  return array(
    'forum' => array(

      'name' => t('Forum topic'),

      'module' => 'forum',
      'description' => t('Create a new topic for discussion in the forums.'),
      'title_label' => t('Subject'),
    )
  );

}

/**
 * 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 'delete revision':

      db_query('DELETE FROM {forum} WHERE vid = %d', $node->vid);
      break;
  }
}

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

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

  if ($op == 'delete' && $term['vid'] == _forum_get_vid()) {

    switch ($type) {
      case 'term':

        $results = db_query('SELECT f.nid FROM {forum} f WHERE f.tid = %d', $term['tid']);

        while ($node = db_fetch_object($results)) {
          // node_delete will also remove any association with non-forum vocabularies.
          node_delete($node->nid);
        }

        // For containers, remove the tid from the forum_containers variable.
        $containers = variable_get('forum_containers', array());

        $key = array_search($term['tid'], $containers);
        if ($key !== FALSE) {

          unset($containers[$key]);
        }
        variable_set('forum_containers', $containers);
        break;
      case 'vocabulary':
        variable_del('forum_nav_vocabulary');

    }

  }
}

function forum_admin_settings() {

  $form = array();

  $number = drupal_map_assoc(array(5, 10, 15, 20, 25, 30, 35, 40, 50, 60, 80, 100, 150, 200, 250, 300, 350, 400, 500));

  $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($form);

}

/**
 * Implementation of hook_form_alter().
 */
function forum_form_alter($form_id, &$form) {
  // hide critical options from forum vocabulary
  if ($form_id == 'taxonomy_form_vocabulary') {
    if ($form['vid']['#value'] == _forum_get_vid()) {
      $form['help_forum_vocab'] = array(
        '#value' => t('This is the designated forum vocabulary. Some of the normal vocabulary options have been removed.'),
        '#weight' => -1,
      );
      $form['nodes']['forum'] = array('#type' => 'checkbox', '#value' => 1, '#title' => t('forum topic'), '#attributes' => array('disabled' => '' ), '#description' => t('forum topic is affixed to the forum vocabulary.'));
      $form['hierarchy'] = array('#type' => 'value', '#value' => 1);
      unset($form['relations']);
      unset($form['tags']);
      unset($form['multiple']);
      $form['required'] = array('#type' => 'value', '#value' => 1);
    }
    else {
      unset($form['nodes']['forum']);
    }
  }
}

/**
 * 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.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_view().
 */

function forum_view(&$node, $teaser = FALSE, $page = FALSE) {

  if ($page) {

    $vocabulary = taxonomy_get_vocabulary(variable_get('forum_nav_vocabulary', ''));

    // Breadcrumb navigation

    $breadcrumb = array();
    $breadcrumb[] = array('path' => 'forum', 'title' => $vocabulary->name);

    if ($parents = taxonomy_get_parents_all($node->tid)) {

      $parents = array_reverse($parents);
      foreach ($parents as $p) {

        $breadcrumb[] = array('path' => 'forum/'. $p->tid, 'title' => $p->name);

      }
    }

    $breadcrumb[] = array('path' => 'node/'. $node->nid);
    menu_set_location($breadcrumb);

  }

  $node = node_prepare($node, $teaser);

  if (!$teaser) {
    $node->content['forum_navigation'] = array(
      '#value' => theme('forum_topic_navigation', $node),
      '#weight' => 100,
    );
  }

  return $node;

}

/**

 * Implementation of hook_submit().
 *
 * Check in particular that only a "leaf" term in the associated taxonomy
 * vocabulary is selected, not a "container" term.

 */

function forum_submit(&$node) {

  // Make sure all fields are set properly:

  $node->icon = $node->icon ? $node->icon : '';

  if ($node->taxonomy) {

    // Get the forum terms from the (cached) tree
    $tree = taxonomy_get_tree(_forum_get_vid());
    if ($tree) {
      foreach ($tree as $term) {
        $forum_terms[] = $term->tid;
      }
    }

    foreach ($node->taxonomy as $term) {

      if (in_array($term, $forum_terms)) {

        $node->tid = $term;

      }

    }

    $old_tid = db_result(db_query_range("SELECT tid FROM {forum} WHERE nid = %d ORDER BY vid DESC", $node->nid, 0,1));

    if ($old_tid) {

      if (($node->tid != $old_tid) && $node->shadow) {
        // A shadow copy needs to be created. Retain new term and add old term.
        $node->taxonomy[] = $old_tid;

      }
    }

  }

}

/**
 * Implementation of hook_validate().
 *
 * Check in particular that only a "leaf" term in the associated taxonomy
 * vocabulary is selected, not a "container" term.
 */
function forum_validate($node) {
  if ($node->taxonomy) {
    // Extract the node's proper topic ID.
    $vocabulary = variable_get('forum_nav_vocabulary', '');
    $containers = variable_get('forum_containers', array());
    foreach ($node->taxonomy as $term) {
      if (db_result(db_query('SELECT COUNT(*) FROM {term_data} WHERE tid = %d AND vid = %d', $term, $vocabulary))) {
        if (in_array($term, $containers)) {
          $term = taxonomy_get_term($term);
          form_set_error('taxonomy', t('The item %forum is only a container for forums. Please select one of the forums below it.', array('%forum' => $term->name)));
        }
      }
    }
  }

}

/**
 * Implementation of hook_update().
 */
function forum_update($node) {
  if ($node->revision) {

    db_query("INSERT INTO {forum} (nid, vid, tid) VALUES (%d, %d, %d)", $node->nid, $node->vid, $node->tid);
  }
  else {
    db_query('UPDATE {forum} SET tid = %d WHERE vid = %d', $node->tid, $node->vid);
  }

}

/**
 * Implementation of hook_form().
 */

function forum_form(&$node) {

  $type = node_get_types('type', $node);

  $form['title'] = array('#type' => 'textfield', '#title' => check_plain($type->title_label), '#default_value' => !empty($node->title) ? $node->title : '', '#required' => TRUE, '#weight' => -5);

  if (!empty($node->nid)) {

    $forum_terms = taxonomy_node_get_terms_by_vocabulary(_forum_get_vid(), $node->nid);

    // if editing, give option to leave shadows

    $shadow = (count($forum_terms) > 1);

    $form['shadow'] = array('#type' => 'checkbox', '#title' => t('Leave shadow copy'), '#default_value' => $shadow, '#description' => t('If you move this topic, you can leave a link in the old forum to the new forum.'));

  }

  $form['body_filter']['body'] = array('#type' => 'textarea', '#title' => check_plain($type->body_label), '#default_value' => !empty($node->body) ? $node->body : '', '#rows' => 20, '#required' => TRUE);

  $form['body_filter']['format'] = filter_form($node->format);

  return $form;

}

/**
 * Implementation of hook_prepare; assign forum taxonomy when adding a topic from within a forum.
 */
function forum_prepare(&$node) {

  if (empty($node->nid)) {

    // new topic

    $node->taxonomy[arg(3)]->vid = _forum_get_vid();
    $node->taxonomy[arg(3)]->tid = arg(3);

  }
}

/**
 * Implementation of hook_insert().
 */
function forum_insert($node) {
  db_query('INSERT INTO {forum} (nid, vid, tid) VALUES (%d, %d, %d)', $node->nid, $node->vid, $node->tid);
}

/**
 * Implementation of hook_delete().
 */
function forum_delete(&$node) {
  db_query('DELETE FROM {forum} WHERE nid = %d', $node->nid);

}

/**
 * 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()) {
  // Handle a delete operation.
  $form['name'] = array(
    '#title' => t('Container name'),
    '#type' => 'textfield',
    '#default_value' => $edit['name'],

    '#maxlength' => 255,

    '#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' => 'value', '#value' => $edit['tid']);
  }

  $form['#base'] = 'forum_form';

  return $form;

}

function forum_form_main($type, $edit = array()) {
  if ($_POST['op'] == t('Delete') || $_POST['confirm']) {
    return drupal_get_form('forum_confirm_delete', $edit['tid']);
  }
  switch ($type) {
    case 'forum':
      return drupal_get_form('forum_form_forum', $edit);
      break;
    case 'container':
      return drupal_get_form('forum_form_container', $edit);
      break;
  }
}

/**
 * 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' => 255,

    '#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 lighter (smaller) 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']);
  }

  $form['#base'] = 'forum_form';

  return $form;

}

/**
 * Process forum form and container form submissions.
 */
function forum_form_submit($form_id, $form_values) {
  if ($form_id == 'forum_form_container') {
    $container = TRUE;
    $type = t('forum container');
  }
  else {

    $container = FALSE;

    $type = t('forum');
  }

  $status = taxonomy_save_term($form_values);
  switch ($status) {
    case SAVED_NEW:
      if ($container) {
        $containers = variable_get('forum_containers', array());
        $containers[] = $form_values['tid'];
        variable_set('forum_containers', $containers);
      }

      drupal_set_message(t('Created new @type %term.', array('%term' => $form_values['name'], '@type' => $type)));

      break;
    case SAVED_UPDATED:

      drupal_set_message(t('The @type %term has been updated.', array('%term' => $form_values['name'], '@type' => $type)));

      break;
  }

  return 'admin/content/forum';

}

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