<?php

/*
 * Edit section defines an input filter that adds an [edit] to every h1-h6 class n a node
 * so you can only edit this part of the node
 */

/*
 * D7 port by M.Kleine-Albers
 * e-anima http://drupal.org/user/255202
 */



define('_EDIT_SECTION_REGEX', '/<h1|<h2|<h3|<h4|<h5|<h6/i');    // all heading tags, case insensitive


function edit_section_filter_info() {  
  
  $filters['edit_section_filter'] = array (
    'title' => t('Edit section'),
    'description' => t('Allows users to edit sections individually.'),
    'process callback' => '_edit_section_filter_process',   
    'prepare callback' => '_edit_section_filter_prepare',          
  );     
            
  return $filters;  
}

/*
 * edit_section filter prepare callback
 * prepare the string, see http://drupal.org/project/examples for filter example
 */

function _edit_section_filter_prepare($text, $filter, $format, $langcode, $cache, $cache_id) {
  return $text;
}

/**
 * edit_section filter process callback
 *
 * The actual filtering is performed here. The supplied text should be returned,
 * once any necessary substitutions have taken place. Adds [edit] next to h1-h6 html tags.
 */

function _edit_section_filter_process($text, $filter, $format, $langcode, $cache, $cache_id) {
  
  if(arg(0) == 'node' && is_numeric(arg(1))) {    // are we actually on a node page?
      
        $node = node_load(arg(0));  // this will already be cached
        //dpm(arg(1));
        
        //if(node_access('update', $node))    // does the user have update access for the node?
          _edit_section_add_links($text);
      }
      //dpm($text);
      return $text;
}


/*
 * callback to actually add [edit]link
 */

function _edit_section_add_links_callback($matches) {
  global $_edit_section_sid;
  
  $link = l('edit', 'node/' . arg(1) . '/edit/' . $_edit_section_sid);
  $_edit_section_sid++;
  
  //dsm("one");
  return '<span id="edit-section">' . $link . '</span>' . $matches[0];
}

/*
 * add an [edit] to each h1-h6 html tag with a link to edit this section
 */

function _edit_section_add_links(&$text) {
  global $_edit_section_sid;
  $_edit_section_sid = 0;
  //dsm("two");
  $text = preg_replace_callback(_EDIT_SECTION_REGEX, '_edit_section_add_links_callback', $text);
}


/*
 * implementation of hook_menu
 * http://api.drupal.org/api/function/hook_menu/7
 */

function edit_section_menu() {

  $items['node/%node/edit/%'] = array(
    'title' => 'Edit',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('edit_section_form', 1, 3), //url is in form of node/1373/edit/0
    'access callback' => 'node_access',
    'access arguments' => array('update', 1),
    'type' => MENU_CALLBACK
  );
 
  return $items;
}

/*
 * getting the offset because we only want to edit a section of the whole body
 */

function _edit_section_get_offsets($text, $section_id) {
  

  preg_match_all(_EDIT_SECTION_REGEX, $text, $matches, PREG_OFFSET_CAPTURE);
  
//  dsm("section_id");
//  dsm($section_id);
  
  $offsets['start'] = $matches[0][$section_id][1];   // get the start offset of the section
  $h = $matches[0][$section_id][0][2];               // get heading ordinal of the section


  // find the next section that has the same or lower heading ordinal

  $section_id++;
  
  if (isset($matches[0][$section_id])) {
    while($matches[0][$section_id] && $matches[0][$section_id][0][2] > $h)
      $section_id++;
  }
  
  if(isset($matches[0][$section_id]))
    $offsets['end'] = $matches[0][$section_id][1];   // the end offset is the start of the section we found
  else
    $offsets['end'] = strlen($text);   // we ran out of sections - the end offset is the length of the text
  
  return $offsets;
}


/**
 * FAPI definition for the edit section form.
 *
 * ...
 * @ingroup forms
 * @see edit_section_form_submit()
 */
function edit_section_form($form, $form_state, $node, $section_id) {
  
//  dsm("form_state");
//  dsm($form_state);
//  
//   dsm("section_id");
//   dsm($section_id);
//   dsm("node");
//   dsm($node);
//  
   //new d7 way to get the body, direct access like $node->body['und'][0]['safe_value'] is bad!
  $body = field_get_items('node', $node, 'body', $node->language);  
    
  $offsets = _edit_section_get_offsets($body[0]['value'], $section_id);

  $form['section'] = array(
    //'#type' => 'textarea',
    '#title' => t('Section'),
    '#rows' => 20,
    '#type' => 'text_format',
    '#default_value' => substr($body[0]['value'], $offsets['start'], $offsets['end'] - $offsets['start'])
  );
  
  /* output informations about the filter */
//  $tips['tips'] = _filter_tips($body[0]['format'], FALSE);  
//  
//  $form['filter_tips'] = array(   
//    '#type' => 'item',
//    '#markup' => theme('filter_tips', $tips) . theme('filter_tips_more_info'),
//  );
  
  //dsm($form);
  
  $node_options = variable_get('node_options_'. $node->type, array('status', 'promote'));
  $revision = in_array('revision', $node_options);


  // Add a revision field if the "Create new revision" option is checked, or if the
  // current user has the ability to check that option.
  
  if($revision || user_access('administer nodes')) {
  
    $form['revision_information'] = array(
      '#type' => 'fieldset',
      '#title' => t('Revision information'),
      '#collapsible' => TRUE,
      '#collapsed' => TRUE
    );
    
    $form['revision_information']['revision'] = array(
      '#access' => user_access('administer nodes'),
      '#type' => 'checkbox',
      '#title' => t('Create new revision'),
      '#default_value' => $revision
    );
    
    $form['revision_information']['log'] = array(
      '#type' => 'textarea',
      '#title' => t('Log message'),
      '#rows' => 2,
      '#description' => t('An explanation of the additions or updates being made to help other authors understand your motivations.')
    );
  }
  
  $form['save'] = array(
    '#type' => 'submit',
    '#value' => t('Save')
  );

  $form['#node'] = $node;
  $form['#section_id'] = $section_id;
  $form['#offsets'] = $offsets;

  return $form;
}


/*
 * submit the changes and save them
 */

function edit_section_form_submit($form, &$form_state) {

  $node = $form['#node'];
  $offsets = $form['#offsets'];  
  
  $body = substr($node->body[$node->language][0]['value'], 0, $offsets['start']);
  $body .= $form_state['values']['section']['value'];
  $body .= substr($node->body[$node->language][0]['value'], $offsets['end']);
  
  $node->body[$node->language][0]['value'] = $body;
  
  if($form_state['values']['revision']) {
    $node->revision = TRUE;
    $node->log = $form_state['values']['log'];
  }
  
  node_save($node);
  
  $watchdog_args = array('@type' => $node->type, '%title' => $node->title);
  $node_link = l(t('view'), 'node/'. $node->nid);
  watchdog('content', '@type: updated %title.', $watchdog_args, WATCHDOG_NOTICE, $node_link);
  
  
  $t_args = array('@type' => $node->type, '%title' => $node->title);
  drupal_set_message(t('@type %title has been updated.', $t_args));

  $form_state['redirect'] = 'node/' . $node->nid;
}