<?php
// $Id: invite_stats.module,v 1.4 2008/09/02 17:02:14 smk Exp $

/**
 * @file
 * Displays some statistics about sent invitations.
 */

/**
 * Implementation of hook_theme().
 */
function invite_stats_theme() {
  return array(
    'invite_stats_ranking' => array(
      'arguments' => array('inviters' => NULL, 'rank' => 1),
    ),
    'invite_stats_count' => array(
      'arguments' => array('count' => NULL),
    ),
  );
}

/**
 * Implementation of hook_perm().
 */
function invite_stats_perm() {
  return array('view invite statistics', 'view own invite statistics');
}

/**
 * Implementation of hook_user().
 */
function invite_stats_user($op, &$edit, &$account, $category = NULL) {
  global $user;

  switch ($op) {
    case 'view':
      $view_access = user_access('view invite statistics');
      $view_own_access = user_access('view own invite statistics') && $account->uid == $user->uid;
      if ($view_access || $view_own_access) {
        $items['accepted'] = array(
          'title' => t('Successful'),
          'value' => invite_count($account->uid, 'accepted'),
          'class' => 'successful',
        );
        $items['pending'] = array(
          'title' => t('Pending'),
          'value' => invite_count($account->uid, 'pending'),
          'class' => 'pending',
        );
        $items['expired'] = array(
          'title' => t('Unsuccessful'),
          'value' => invite_count($account->uid, 'expired'),
          'class' => 'expired',
        );
        return array(t('Invitation counts') => $items);
      }
      break;
  }
}

/**
 * Implementation of hook_block().
 */
function invite_stats_block($op = 'list', $delta = 0, $edit = array()) {
  if ($op == 'list') {
    $blocks[0] = array('info' => t('Top inviters/User rank'));
    return $blocks;
  }
  else if ($op == 'view') {
    switch ($delta) {
      case 0:
        if (user_access('view invite statistics')) {
          if (arg(0) == 'user' && is_numeric(arg(1)) && $account = user_load(array('uid' => arg(1)))) {
            $block = array(
              'subject' => t("@user's invite rank", array('@user' => $account->name)),
              'content' => invite_stats_display_user_rank($account->uid),
            );
          }
          else {
            $block = array(
              'subject' => t('Top inviters'),
              'content' => invite_stats_display_top_inviters(),
            );
          }
        }
        break;
    }
    return $block;
  }
  else if ($op == 'configure') {
    switch ($delta) {
      case 0:
        $form['invite_num_ranks'] = array(
          '#type' => 'textfield',
          '#title' => t('Number of inviters'),
          '#default_value' => variable_get('invite_num_ranks', 5),
          '#size' => 3,
          '#maxlength' => 3,
          '#description' => t('Show this number of inviters in the Top inviters and User rank blocks.'),
          '#required' => TRUE,
        );
        return $form;
    }
  }
  else if ($op == 'save') {
    switch ($delta) {
      case 0:
        variable_set('invite_num_ranks', (int)$edit['invite_num_ranks']);
        break;
    }
  }
}

/**
 * Render the "Top inviters" block.
 */
function invite_stats_display_top_inviters() {
  $inviters = array();
  $result = db_query_range("SELECT uid, COUNT(uid) AS count FROM {invite} WHERE joined <> 0 GROUP BY uid ORDER BY count DESC", 0, variable_get('invite_num_ranks', 5));
  while ($row = db_fetch_object($result)) {
    $inviters[] = $row;
  }
  return theme('invite_stats_ranking', $inviters);
}

/**
 * Render the displayed user's rank block.
 */
function invite_stats_display_user_rank($uid) {
  $inviters = array();
  $max = variable_get('invite_num_ranks', 5);

  // Get user's invite count.
  $user_invite_stats_count = db_result(db_query("SELECT COUNT(*) FROM {invite} WHERE uid = %d AND joined <> 0", $uid));

  // Calculate user's rank.
  $result = db_query("SELECT DISTINCT COUNT(uid) FROM {invite} WHERE joined <> 0 GROUP BY uid HAVING COUNT(uid) > %d", $user_invite_stats_count);
  $rank = 1;
  while ($row = db_fetch_array($result)) {
    $rank++;
  }

  // Fetch users with more invites.
  $i = 0;
  $prev_count = 0;
  $result = db_query_range("SELECT uid, COUNT(uid) AS count FROM {invite} WHERE joined <> 0 GROUP BY uid HAVING COUNT(uid) > %d ORDER BY count ASC", $user_invite_stats_count, 0, $max - 1);
  while ($row = db_fetch_object($result)) {
    if ($row->count != $prev_count) {
      $prev_count = $row->count;
      $rank--; // Decrement initial rank
    }
    array_unshift($inviters, $row);
  }

  // Add current user, now we have invite_num_ranks users at max.
  $inviters[] = (object)array('uid' => $uid, 'count' => $user_invite_stats_count);
  $user_idx = count($inviters);

  // Add users with equal or less invites.
  $i = 0;
  $prev_count = $user_invite_stats_count;
  $result = db_query_range("SELECT uid, COUNT(uid) AS count FROM {invite} WHERE joined <> 0 GROUP BY uid HAVING COUNT(uid) <= %d AND uid <> %d ORDER BY count DESC", $user_invite_stats_count, $uid, 0, $max - 1);
  while ($row = db_fetch_object($result)) {
    $inviters[] = $row;
  }

  // Slice result.
  $start = max($user_idx - 1 - floor($max / 2), 0);
  if (count($inviters) - $user_idx < floor($max / 2)) {
    $start -= max(count($inviters) - $user_idx, floor($max / 2));
    $start = max($start, 0);
  }
  $inviters = array_slice($inviters, $start, $max);

  return theme('invite_stats_ranking', $inviters, $rank);
}

/**
 * Theme the Top inviters/user rank block.
 *
 * @param $inviters
 *   An array of arrays consisting of the user id and invite count.
 * @param $rank
 *   The rank of the first inviter in the list.
 *
 * @ingroup themeable
 */
function theme_invite_stats_ranking($inviters, $rank = 1) {
  if ($inviters) {
    global $user;

    $header = array();
    $rows = array();
    $prev_count = 0;
    foreach ($inviters as $inviter) {
      $row = array();
      if ($inviter->count != $prev_count) {
        $row[] = array('data' => "$rank.", 'style' => 'width: 5%');
        $prev_count = $inviter->count;
        $rank++;
      }
      else {
        $row[] = '';
      }
      $row[] = theme('username', user_load(array('uid' => $inviter->uid)));
      $row[] = array('data' => theme('invite_stats_count', $inviter->count), 'align' => 'right');
      $rows[] = array('data' => $row, 'class' => ($inviter->uid == $user->uid ? 'current-user' : ''));
    }

    return theme('table', $header, $rows, array('id' => 'invite-ranks'));
  }
}

/**
 * Theme an invite count.
 *
 * @param $count
 *   A number.
 *
 * @ingroup themeable
 */
function theme_invite_stats_count($count) {
  $title = format_plural($count, '1 invite', '@count invites');
  return '<span class="count" title="'. $title .'">'. $count .'</span>';
}