<?php

/**
 * @file
 * Tracks visited pages.
 */

/**
 * Implements hook_init().
 */
function tracks_init() {
  // Grab the tracking history from a variable.
  $track = variable_get('tracks_history', array());

  // Add current page to track.
  $track[] = array(
    'title' => strip_tags(drupal_get_title()),
    'path' => $_GET['q'],
    'timestamp' => REQUEST_TIME,
  );

  // Save track as a variable.
  variable_set('tracks_history', $track);
}

/**
 * Implements hook_permission().
 */
function tracks_permission() {
  return array(
    'administer tracks' => array(
      'title' => t('Administer Tracks module'),
      'description' => t('Perform admin tasks for Tracks module.'),
    ),
    'access tracks blocks' => array(
      'title' => t('Access Tracks blocks'),
      'description' => t('View blocks generated by Tracks module.'),
    ),
  );
}

/**
 * Implements hook_menu().
 */
function tracks_menu() {
  // Module settings.
  $items['admin/config/tracks'] = array(
    'title' => 'Tracks',
    'description' => 'tracks configuration',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('tracks_admin_settings'),
    'access arguments' => array('administer tracks'),
    'file' => 'tracks.admin.inc',
    'file path' => drupal_get_path('module', 'tracks'),
  );
  return $items;
}

/**
 * Implements hook_cron().
 */
function tracks_cron() {
  // Get track array.
  $track = variable_get('tracks_history', array());

  // Get offset for array_slice, save last five items.
  $count_minus_5 = count($track) - 5;

  // Eliminate everything except the last five.
  $short_track = array_slice($track, $count_minus_5);

  // Save the shorter list.
  variable_set('tracks_history', $short_track);
}

/**
 * Implements hook_block_info().
 */
function tracks_block_info() {
  $blocks['history'] = array(
    'info' => t('History'),
    'cache' => DRUPAL_NO_CACHE,
  );
  return $blocks;
}

/**
 * Implements hook_block_configure().
 */
function tracks_block_configure($delta = '') {
  // Get max allowed from config.
  $max_to_display = variable_get('tracks_block_max', 50);

  // Add a select box of numbers form 1 to $max_to_display.
  $form['tracks_block_num'] = array(
    '#type' => 'select',
    '#title' => t('Number of items to show'),
    '#default_value' => variable_get('tracks_block_num', '5'),
    '#options' => drupal_map_assoc(range(1, $max_to_display)),
  );
  return $form;
}

/**
 * Implements hook_block_save().
 */
function tracks_block_save($delta = '', $edit = array()) {
  variable_set('tracks_block_num', $edit['tracks_block_num']);
}

/**
 * Implements hook_block_view().
 */
function tracks_block_view($delta = '') {
  if (user_access('access tracks blocks')) {
    $block = array();
    $type = $delta;
    // list($type, $id) = explode('-', $delta); // Unnecessary with one block.
    switch ($type) {
      case 'history':
        // Create list of previous paths.
        // Get history from variable.
        $track = variable_get('tracks_history', array());

        // Flip saved array to show newest pages first.
        $reverse_track = array_reverse($track);

        // Get number of items to display.
        $num_items = variable_get('tracks_block_num', '5');

        // Output latest items as list.
        // Initialize variable.
        $output = '';
        for ($i = 0; $i < $num_items; $i++) {
          if ($item = $reverse_track[$i]) {
            $output .= '<li>'
                . l($item['title'], $item['path'])
                . ' - '
                . format_interval(REQUEST_TIME - $item['timestamp'])
                . ' '
                . t('ago')
                . '</li>';
          }
        }
        if (isset($output)) {
          $output = '
            <p>' . t('Last @num pages you visited.', array('@num' => $num_items)) . '</p>
            <ul>' . $output . '</ul>
          ';
        }

        // Return the $block variable with subject (title) and content (output).
        $block['subject'] = 'History';
        $block['content'] = $output;
        break;
    }

    return $block;
  }
}