<?php
// $Id: pivots_block.module,v 1.28 2011-01-25 19:19:05 drumm Exp $

/**
 * @file
 * This file provides the pivots_blocks that generates module recommendations.
 *
 * Current limitations/issues:
 *   1. Recommendation data is stored externally on master-other.drupal.org database.
 *      The reason to use external database is to give flexibility to developers to tweak the algorithm.
 *   2. "More" is disabled temporarily to make the code clearer, will be added later if needed.
 *
 * This module was developed with support from the National Science
 * Foundatio under award IIS-0812042. Any opinions, findings, and conclusions
 * or recommendations expressed or embodied in this software are those of the
 * author(s) and do not necessarily reflect the views of the National Science
 * Foundation.
 */

define('PID_DOUBLE', 5006);       // double pivot algorithm ID that displays related projects in different algorithms.
define('LIMIT_DOUBLE', 5);
define('LIMIT_MAX', 100);         // maximum items to display in the block or on a page.

function pivots_block_output() {
  // Skip the Drupal core project.
  if (($node = project_get_project_from_menu()) && ($node->nid != DRUPALORG_CORE_NID)) {

    //HACK: randomize algorithm rotation
    $_pivots_block_pid_double = PID_DOUBLE;  // double pivot ID defaults to conversation pivots
    switch (rand(0,2)) {
      case 0:
        $_pivots_block_pid_double = 5004; // conversation pivots
        break;
      case 1:
        $_pivots_block_pid_double = 5005; // solr10
        break;
      case 2:
        $_pivots_block_pid_double = 5006; // corrhr + solr10
        break;
    }

    $output = _pivots_block_content($node->nid, $_pivots_block_pid_double, t("Related projects"), LIMIT_DOUBLE);
    //$output .= _pivots_block_suggestbox($node->nid, $_pivots_block_pid_double);
    return $output;
  }
}

function _pivots_block_content($node_id, $pivot_id, $title, $limit) {
  $output = '';
  $ga_event = "$node_id";
  $items = _pivots_block_generate_items($node_id, $pivot_id, $limit);
  if (!empty($items)) {
    foreach ($items as $position => $item) {
      $items[$position] = l($item['title'], "node/{$item['nid']}", array( 'attributes' => array(
              "onClick" => "javascript:pageTracker._trackEvent('PivotsClick_${pivot_id}', '${node_id}_{$item['nid']}');",
              "rel"     => "nofollow"
      )));
      $ga_event .= "_{$item['nid']}";
    }
    //$output = theme('item_list', $items, $title);
    $output = theme('item_list', $items); // hack: don't show title
  }
  $GLOBALS['conf']['googleanalytics_codesnippet_after'] .= "gaq.push(['_trackEvent', 'PivotsPageview_{$pivot_id}', '{$ga_event}']);";
  return $output;
}

function _pivots_block_generate_items($node_id, $pivot_id, $limit) {
  if ($limit <= 0) {
    $limit = LIMIT_MAX;
  }

  db_set_active('pivots');  // NOTE: here we activate the pivots database.
  // if there's database failure, we just pretend nothing happens whatsoever. pivots_block returns nothing in this case.
  $matches = @db_query("SELECT DISTINCT dest_id FROM {pivots_match} WHERE pivot_id=%d AND src_id=%d
        AND dest_id<>%d ORDER BY score DESC", $pivot_id, $node_id, $node_id);
  db_set_active();  // NOTE: change back to use the default database

  $count = 0;
  $items = array();
  while (($match = @db_fetch_array($matches)) && $count < $limit) {
    $dest_id = $match['dest_id'];
    $result = db_query("SELECT title FROM {node} WHERE nid=%d AND status=1", $dest_id);
    // there might be cases that the node was deleted, or set to unpublished between pivots database refresh
    // so here we only count the valid node.
    $title = db_result($result);
    if ($title) {
      $items[] = array('nid' => $dest_id, 'title' => $title, 'pid' => $pivot_id);
      $count++;
    }
  }
  return $items;
}

/*function _pivots_block_suggestbox($node_id, $pivot_id) {
  $form = array();
  $form['suggestion'] = array (
    '#type' => 'textfield',
    //'#description' => t("Please suggest related projects. Multiple suggestions require multiple submission."),
    '#size' => 20,
    '#maxlength' => 128,
    '#weight' => 0,
    '#id' => 'pivots_block_suggestbox',
  );
  $form['submit'] = array(
    '#type' => 'button',
    '#value' => t('Suggest project!'),
    '#weight' => 1,
    '#id' => 'pivots_block_suggestbutton'
  );

  drupal_add_js("
      $(document).ready(function() {
        $('#pivots_block_suggestbutton').click(function() {
          var pattern = /^http[:][/][/]drupal[.]org[/]project[/]\w+$/;
          var suggestion = $('#pivots_block_suggestbox').val();
          while (!suggestion.match(pattern)) {
            suggestion = prompt('Please suggest a related project using URLs such as http://drupal.org/project/cck. Thank you.');
            if (!suggestion) break;
          }
          if (suggestion) {
            alert('Thank you for suggesting a related project. All suggestions will be aggregated and updated to the results soon.');
            pageTracker._trackEvent('PivotsSuggest_${pivot_id}', '${node_id}_'+suggestion);
          }
        });
      });
    ", 'inline');

  return drupal_render_form('pivots_block_suggestbox', $form);
}*/

/**
 * Implementation of hook_block()
 */
function pivots_block_block($op = 'list', $delta = 0, $edit = array()) {
  switch ($op) {
    case 'list':
      return array(
        array(
          'info' => t('pivots_block: Recommendations'),
          'cache' => BLOCK_CACHE_PER_PAGE,
          'pages' => 'project/*',
        ),
      );
      return $blocks;

    case 'view':
      $block['subject'] = t('Related projects');
      $block['content'] = pivots_block_output();
      return $block;
  }
}