<?php
// $Id: talk.module,v 1.6.2.1 2008-09-17 16:07:35 heine Exp $

/**
 * @file
 * Comments are displayed in a separate 'talk' tab, for node types you wish
 */

/**
 * Implementation of hook_help().
 */
function talk_help($path, $arg) {
  switch ($path) {
    case 'admin/help#talk':
      $output = '<p>'. t('The talk module gives you the option to display comments on a seperate tab. The option is per content type and can be set in the workflow options of a content type.') .'</p>';
      return $output;
  }
}

/**
 * Implementation of hook_menu().
 */
function talk_menu() {
  $items = array();
  $items['node/%node/talk'] = array(
    'title callback' => 'talk_menu_title',
    'page callback' => 'talk_handle',
    'page arguments' => array(1),
    'access callback' => '_talk_access',
    'access arguments' => array(1),
    'type' => MENU_LOCAL_TASK,
    'weight' => 1,
  );
  $items['admin/settings/talk'] = array(
    'title' => t('Talk page'),
    'description' => t('Configure settings for the talk page.'),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('talk_admin_form'),
    'access arguments' => array('administer site configuration'),
  );
  return $items;
}

/**
 * Helper item for talk_menu: access callback.
 */
function _talk_access($node) {
  return ($node->nid && _talk_node_comment_value($node) && talk_activated($node->type) && user_access('access comments') && node_access('view', $node));
}

/**
 * Menu call back for admin form.
 */
function talk_admin_form() {
  $form = array();
  $form['talk_title'] = array(
    '#type' => 'textfield',
    '#title' => t('Title of the "talk" page'),
    '#default_value' => talk_title(),
  );
  return system_settings_form($form);
}

function talk_title($title = NULL) {
  if (is_null($title)) {
    return variable_get('talk_title', t('Talk'));
  }
  variable_set('talk_title', $title);
}

/**
 * Menu callback for the title, as it would automatically pass args in, which would be bad.
 */
function talk_menu_title() {
  return talk_title();
}

/**
 * Menu callback for talk page.
 */
function talk_handle($node) {
  drupal_set_title(check_plain($node->title));
  $add_comments = _talk_node_comment_value($node) == COMMENT_NODE_READ_WRITE && user_access('post comments');
  return theme('talkpage', $node, $add_comments);
}

/**
 * Implementation of hook_nodeapi().
 */
function talk_nodeapi(&$node, $op) {
  switch ($op) {
    case 'load':
      if (talk_activated($node->type) && arg(0) == 'node' && !arg(2)) {
        // Overwrite setting of comment module and set comments for this node to disabled.
        // This prevents the comments of being displayed.
        $output['comment_original_value'] = $node->comment;
        $output['comment'] = 0;
        return $output;
      }
      break;
  }
}

/**
 * Implementation of hook_link().
 */
function talk_link($type, $node = NULL, $teaser = FALSE) {
  if ($type == 'node' && talk_activated($node->type) && user_access('access comments') && _talk_node_comment_value($node)) {
    $result = array();
    if ($node->comment_count) {
      $result['talk_view'] = array(
        'title' => t('@title page (@nr comments)', array('@nr' => $node->comment_count, '@title' => talk_title())),
        'href' => 'node/'. $node->nid .'/talk',
      );
    }
    if (_talk_node_comment_value($node) == COMMENT_NODE_READ_WRITE) {
      $result['talk_view'] = array(
        'title' => t('Add new comment'),
        'href' => "comment/reply/$node->nid",
      );
    }
    return $result;
  }
}

/**
 * Implementation of hook_form_alter().
 */
function talk_form_alter(&$form, $form_state, $form_id) {
  // Add option to comment options of node types.
  if ($form_id == 'node_type_form' && isset($form['identity']['type']) && module_exists('comment')) {
    $form['workflow']['comment_talk'] = array(
      '#type' => 'checkbox',
      '#title' => t('Display comments on separate talk page'),
      '#prefix' => '<strong>'. t('Talk pages:') .'</strong>',
      '#weight' => 5,
      '#default_value' => talk_activated($form['#node_type']->type),
    );
  }
}

/**
 * Implementation of hook_link_alter().
 */
function talk_link_alter(&$links, $node) {
  if (talk_activated($node->type)) {
    unset($links['comment_add']);
  }
}

/**
 * Implementation of hook_comment()
 * Changing the destination to the talk page after posting a comment
 */
function talk_comment($a1, $op) {
  if ($op == 'insert' || $op == 'update') {
    $nid = $a1['nid'];
    $node = node_load($nid);
    if (talk_activated($node->type)) {
      $_REQUEST['destination'] = 'node/'. $a1['nid'] .'/talk';
    }
  }
} 
/**
 * Is talk page option activated for node tpye?
 */
function talk_activated($node_type, $value = NULL) {
  if (is_null($value)) {
    return variable_get('comment_talk_'. $node_type, FALSE);
  }
  variable_set('comment_talk_'. $node_type, $value);
}

/**
 * Value of 'comment' of node.
 */
function _talk_node_comment_value(&$node) {
  return isset($node->comment_original_value) ? $node->comment_original_value : $node->comment;
}
 
/**
 * Implementation of hook_theme().
 */
function talk_theme() {
  return array(
    'talkpage' => array(
      'template' => 'talkpage',
      'arguments' => array('node' => NULL, 'add_comments' => NULL),
    ),
  );
}

/**
 * Theme talkpage for node
 * @param $node
 *   node whose talk page is displayed
 * @param $add_comments
 *   boolean which indicates if the adding of comments is allowed for current user
 * @ingroup themeable
 */
function template_preprocess_talkpage(&$variables) {
  $add_comments = $variables['add_comments'];
  $node = $variables['node'];
  $variables['title'] = talk_title();
  $comment_link = '';
  if ($add_comments) {
    $comment_link = l(t('Add new comment'), "comment/reply/$node->nid");
  }
  $comments = comment_render($node, 0);
  $redisplay = FALSE;
  if ($node->comment_count > 1 && $add_comments) {
    $redisplay = TRUE;
  }
  $variables['redisplay'] = $redisplay;
  $variables['comment_link'] = $comment_link;
  $variables['comments'] = $comments;
}