<?php

/**
 * @file
 * Module file for Legal.
 */

/**
 * Implements hook_help().
 */
function legal_help($path, $arg) {
  $output = '';
  switch ($path) {
    case 'admin/help#legal':
      $output .= t('Display a Terms & Conditions statement on the registration page, require visitor to accept T&C to register. When a user creates an account they are required to accept your Terms & Conditions to complete their registration.');
      break;
    case 'admin/settings/legal':
      $output .= t('Display a Terms & Conditions statement on the registration page, require visitor to accept the T&C to register. A <a href="@page">page</a> displaying your T&C will be automatically created, access to this page can be set via the <a href="@access">permissions</a> administration page.',
        array('@page' => url('legal'), '@access' => url('admin/user/permissions')));
  }

  return $output;
}

/**
 * Implements hook_perm().
 */
function legal_permission() {
  return array(
    'administer Terms and Conditions' => array(
      'title' => t('Administer Terms and Conditions'),
    ),
    'view Terms and Conditions'       => array(
      'title' => t('View Terms and Conditions'),
    ),
  );
}

/**
 * Implements hook_access().
 */
function legal_access($op, $node, $account) {
  return ($op == 'view' && (user_access('view Terms and Conditions') || user_access('administer Terms and Conditions')));
}

/**
 * Implements hook_menu().
 */
function legal_menu() {
  $items = array();

  $items['admin/config/people/legal'] = array(
    'title'            => 'Legal',
    'page callback'    => 'drupal_get_form',
    'page arguments'   => array('legal_administration'),
    'access arguments' => array('administer Terms and Conditions'),
    'description'      => 'Display Terms and Conditions statement on the registration page.',
    'file'             => 'legal.admin.inc',
  );

  $items['admin/config/people/legal/terms'] = array(
    'title'            => 'Add T&C',
    'access arguments' => array('administer Terms and Conditions'),
    'description'      => 'Display Terms and Conditions statement on the registration page.',
    'type'             => MENU_DEFAULT_LOCAL_TASK,
  );

  $items['admin/config/people/legal/languages'] = array(
    'title'            => 'Languages',
    'page callback'    => 'drupal_get_form',
    'page arguments'   => array('legal_languages'),
    'access callback'  => 'legal_languages_access',
    'access arguments' => array('administer Terms and Conditions'),
    'description'      => 'Display Terms and Conditions statement on the registration page.',
    'weight'           => 10,
    'type'             => MENU_LOCAL_TASK,
    'file'             => 'legal.admin.inc',
  );

  $items['legal'] = array(
    'title'            => 'Terms and Conditions',
    'page callback'    => 'legal_page',
    'access arguments' => array('view Terms and Conditions'),
    'type'             => MENU_CALLBACK,
    'file'             => 'legal.pages.inc',
  );

  $items['legal_accept/%/%'] = array(
    'title'           => 'Terms and Conditions',
    'page callback'   => 'drupal_get_form',
    'page arguments'  => array('legal_login', 1, 2),
    'access callback' => TRUE,
    'type'            => MENU_CALLBACK,
  );

  return $items;
}

/**
 * Implements hook_theme().
 */
function legal_theme() {
  return array(
    'legal_administration' => array('render element' => 'form'),
    'legal_display'        => array('variables' => array('form' => NULL)),
    'legal_page'           => array('render element' => 'form'),
    'legal_login'          => array('render element' => 'form'),
    'legal_accept_label' => array('variables' => array('link' => FALSE)),
  );
}

function legal_display_fields($conditions) {
  $form         = array();
  $accept_label = theme('legal_accept_label');

  $form['current_id']     = array(
    '#type'  => 'value',
    '#value' => $conditions['version'],
  );
  $form['language_value'] = array(
    '#type'  => 'value',
    '#value' => $conditions['language'],
  );
  $form['revision_id']    = array(
    '#type'  => 'value',
    '#value' => $conditions['revision'],
  );
  $form['current_date']   = array(
    '#type'  => 'value',
    '#value' => $conditions['date'],
  );
  $form['display']        = array(
    '#type'  => 'value',
    '#value' => variable_get('legal_display', '0'),
  );
  $form['legal']          = array(
    '#type'   => 'fieldset',
    '#title'  => t('Terms and Conditions of Use'),
    '#weight' => 29,
  );

  switch (variable_get('legal_display', '0')) {
    case 1: // Scroll box (CSS).
    case 2: // HTML.
      $form['legal']['conditions'] = array(
        '#markup' => filter_xss_admin($conditions['conditions']),
      );
      break;

    case 3: // Page Link.
      $form['legal']['conditions'] = array(
        '#markup' => '',
      );
      $accept_label                = theme('legal_accept_label', array('link' => TRUE));
      break;

    default: // Scroll box (HTML).
      $form['legal']['conditions'] = array(
        '#type'          => 'textarea',
        '#title'         => t('Terms & Conditions'),
        '#default_value' => $conditions['conditions'],
        '#value'         => $conditions['conditions'],
        '#rows'          => 10,
        '#weight'        => 0,
        '#attributes'    => array('readonly' => 'readonly'),
      );
  }

  if (!empty($conditions['extras'])) {
    foreach ($conditions['extras'] as $key => $label) {
      if (!empty($label)) {
        $form['legal'][$key] = array(
          '#type'          => 'checkbox',
          '#title'         => filter_xss_admin($label),
          '#default_value' => 0,
          '#weight'        => 2,
          '#required'      => TRUE,
        );
      }
    }
  }

  $form['legal']['legal_accept'] = array(
    '#type'          => 'checkbox',
    '#title'         => $accept_label,
    '#default_value' => 0,
    '#weight'        => 50,
    '#required'      => TRUE,
  );

  return $form;
}

function theme_legal_display($variables) {
  $form = $variables['form'];

  if (!empty($form['legal']['conditions']['#markup'])) {
    // Scroll box (CSS).
    if ($form['display']['#value'] == 1) {
      $path = base_path() . drupal_get_path('module', 'legal');
      drupal_add_css(drupal_get_path('module', 'legal') . '/legal.css');
      $form['legal']['conditions']['#prefix'] = '<div class="legal-terms">';
      $form['legal']['conditions']['#suffix'] = '</div>';
    }
  }

  return $form;
}

function theme_legal_page($variables) {
  $form = $variables['form'];

  if (!empty($form['current_id']['#value'])) {
    $form = theme('legal_display', array('form' => $form));

    return drupal_render($form);
  }
}

/**
* Theme the accept terms and conditions label.
*
* @param $variables
*   An associative array of variables for themeing, containing:
*    - link: Whether or not the label contains a link to the legal page.
*
* @ingroup themeable
*/

function theme_legal_accept_label($variables) {

  if ($variables['link']) {
    return t('<strong>Accept</strong> <a href="@terms">Terms & Conditions</a> of Use', array('@terms' => url('legal')));
  }
  else {
    return t('<strong>Accept</strong> Terms & Conditions of Use');
  }
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function legal_form_user_register_form_alter(&$form, &$form_state) {
  global $user;
  global $language;

  $conditions = legal_get_conditions($language->language);

  // Do nothing if there's no Terms and Conditions text set.
  if (empty($conditions['conditions'])) {
    return;
  }

  $form = array_merge($form, legal_display_fields($conditions));

  // Disable checkbox if:
  //  - user is already registered (administer users);
  //  - users with 'administer users' can access registration on admin/user/user/create.
  if (!empty($user->uid)) {
    $form['legal']['legal_accept']['#attributes'] = array('disabled' => 'disabled');
    $form['legal']['legal_accept']['#required']   = FALSE;

    if (is_array($conditions['extras'])) {
      foreach ($conditions['extras'] as $key => $label) {
        if (!empty($label)) {
          $form['legal'][$key]['#attributes'] = array('disabled' => 'disabled');
          $form['legal'][$key]['#required']   = FALSE;
        }
      }
    }
  }

  return theme('legal_display', array('form' => $form));
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function legal_form_user_profile_form_alter(&$form, $form_state) {
  global $user;
  global $language;
  $accepted = FALSE;

  if ($form['#user_category'] != 'account') {
    return;
  }

  // Set reminder to change password if coming from one time login link.
  if (isset($_REQUEST['pass-reset-token'])) {

    $messages = drupal_get_messages('status', FALSE);
    $status_messages = isset($messages['status']) ? $messages['status'] : array();
    $reminder = t('You have just used your one-time login link. It is no longer necessary to use this link to log in. Please change your password.');

    if (!in_array($reminder, $status_messages)) {
      drupal_set_message($reminder);
    }
  }

  $account = $form['#user'];

  // Get last accepted version for this account.
  $legal_account = legal_get_accept($account->uid);

  // If no version has been accepted yet, get version with current language revision.
  if (empty($legal_account['version'])) {
    $conditions = legal_get_conditions($language->language);
    // No conditions set yet.
    if (empty($conditions['conditions'])) return;
  }
  // Get version / revision of last accepted language.
  else {

    $conditions = legal_get_conditions($legal_account['language']);
    // No conditions set yet.
    if (empty($conditions['conditions'])) return;

    // Check latest version of T&C has been accepted.
    $accepted = legal_version_check($account->uid, $conditions['version'], $conditions['revision'], $legal_account);

    // Enable language switching if version accepted and revision up to date.
    if ($accepted && $legal_account['language'] != $language->language) {
      $conditions = legal_get_conditions($language->language);
    }
  }

  $form = array_merge($form, legal_display_fields($conditions));

  if ($accepted === TRUE) {
    $form['legal']['legal_accept']['#value'] = 1;
    if (!empty($conditions['extras'])) {
      foreach ($conditions['extras'] as $key => $label) {
        if (!empty($label)) {
          $form['legal'][$key]['#value'] = 1;
        }
      }
    }
  }

  // Disable checkbox if:
  //  - user is not account owner;
  //  - latest T&C has already been accepted.
  if ($account->uid != $user->uid || $accepted == TRUE) {
    $form['legal']['legal_accept']['#attributes'] = array('disabled' => 'disabled');
    if (!empty($conditions['extras'])) {
      reset($conditions['extras']);
      foreach ($conditions['extras'] as $key => $label) {
        if (!empty($label)) {
          $form['legal'][$key]['#attributes'] = array('disabled' => 'disabled');
        }
      }
    }
  }

  // Not required if user is not account owner.
  if ($account->uid != $user->uid) {
    $form['legal']['legal_accept']['#required'] = FALSE;
    if (!empty($conditions['extras'])) {
      reset($conditions['extras']);
      foreach ($conditions['extras'] as $key => $label) {
        if (!empty($label)) {
          $form['legal'][$key]['#required'] = FALSE;
        }
      }
    }
  }

  // Enable account owner to accept.
  if ($account->uid == $user->uid && $accepted != TRUE) {
    $form['legal']['legal_accept']['#default_value'] = isset($edit['legal_accept']) ? $edit['legal_accept'] : '';
    $form['legal']['legal_accept']['#required']      = TRUE;

    if (!empty($conditions['extras'])) {
      reset($conditions['extras']);

      foreach ($conditions['extras'] as $key => $label) {
        if (!empty($label)) {
          $form['legal'][$key]['#default_value'] = isset($edit[$key]) ? $edit[$key] : '';
          $form['legal'][$key]['#required']      = TRUE;
        }
      }
    }
  }

  return theme('legal_display', array('form' => $form));
}

/**
 * Implements hook_user_login().
 */
function legal_user_login(&$edit, $account) {
  global $user;
  global $language;

  if ($user->uid == 1) {
    return;
  }

  // Get last accepted version for this account
  $legal_account = legal_get_accept($user->uid);

  // If no version has been accepted yet, get version with current language revision.
  if (empty($legal_account['version'])) {
    $conditions = legal_get_conditions($language->language);
    // No conditions set yet.
    if (empty($conditions['conditions'])) {
      return;
    }
  }
  // Get version / revision of last accepted language.
  else {
    $conditions = legal_get_conditions($legal_account['language']);
    // No conditions set yet.
    if (empty($conditions['conditions'])) {
      return;
    }

    // Check latest version of T&C has been accepted.
    $accepted = legal_version_check($user->uid, $conditions['version'], $conditions['revision'], $legal_account);

    if ($accepted) {
      return;
    }
  }

  $uid = $user->uid;

  // Log the user out and regenerate the Drupal session.
  module_invoke_all('user_logout', $user);
  drupal_session_regenerate();

  // We have to use $GLOBALS to unset a global variable.
  $user = drupal_anonymous_user();

  $query = NULL;

  // Deal with destination from password reset one time login link,
  // by creating a new one time login link and setting it as the destination
  // after the T&Cs have been accepted.
  if (arg(0) == 'user' && arg(1) == 'reset') {
    $token = drupal_hash_base64(drupal_random_bytes(55));
    // This is a new, anonymous-user session.
    $_SESSION['pass_reset_' . $uid] = $token;
    $query = array('destination' => "user/$uid/edit?pass-reset-token=$token");
  }

  if (!empty($_REQUEST['destination'])) {
    $query = array('destination' => $_REQUEST['destination']);
  }

  unset($_GET['destination']);

  $result    = db_select('users', 'u')
    ->fields('u')
    ->condition('uid', $uid)
    ->range(0, 1)
    ->execute()
    ->fetchAllAssoc('uid');
  $signatory = array_pop($result);

  drupal_goto('legal_accept/' . $signatory->uid . '/' . md5($signatory->name . $signatory->pass . $signatory->login), array('query' => $query));
}

/**
 * Implementation of hook_user_insert().
 */
function legal_user_insert(&$edit, $account, $category) {
  global $user;
  global $language;

  $conditions = legal_get_conditions($language->language);

  if (empty($conditions['conditions'])) {
    return;
  }

  // Record the accepted state before removing legal_accept from $edit.
  $accepted             = isset($edit['legal_accept']) ? $edit['legal_accept'] : FALSE;
  $edit['legal_accept'] = NULL;
  $edit['conditions']   = NULL;

  foreach ($conditions['extras'] as $key => $label) {
    $edit[$key] = NULL;
  }

  // Don't insert if user is already registered (administrator).
  if (!empty($user->uid)) {
    return;
  }

  if ($accepted) {
    legal_save_accept($conditions['version'], $conditions['revision'], $conditions['language'], $account->uid);
  }
}

/**
 * Implements hook_user_update().
 */
function legal_user_update(&$edit, $account, $category) {
  global $user;
  global $language;

  // We only care about the account category.
  if ($category != 'account') {
    return;
  }

  $conditions = legal_get_conditions($language->language);

  if (empty($conditions['conditions'])) {
    return;
  }

  // Record the accepted state before removing legal_accept from $edit.
  $accepted             = isset($edit['legal_accept']) ? $edit['legal_accept'] : FALSE;
  $edit['legal_accept'] = NULL;
  $edit['conditions']   = NULL;

  foreach ($conditions['extras'] as $key => $label) {
    $edit[$key] = NULL;
  }

  if ($account->uid != $user->uid) {
    return;
  }

  // If already accepted skip data entry.
  $previously_accepted = legal_version_check($account->uid, $conditions['version'], $conditions['revision']);

  if ($previously_accepted === TRUE) {
    return;
  }

  if ($accepted) {
    legal_save_accept($conditions['version'], $conditions['revision'], $conditions['language'], $account->uid);
  }
}

/**
 * Require registered users to accept new T&C.
 */
function legal_login($form, $constructor, $uid, $id_hash = NULL) {
  global $language;

  // get last accepted version for this account
  $legal_account = legal_get_accept($uid);

  // if no version has been accepted yet, get version with current language revision
  if (empty($legal_account['version'])) {
    $conditions = legal_get_conditions($language->language);
    // no conditions set yet
    if (empty($conditions['conditions'])) return;
  }
  else { // get version / revision of last accepted language

    $conditions = legal_get_conditions($legal_account['language']);
    // no conditions set yet
    if (empty($conditions['conditions'])) return;

    // Check latest version of T&C has been accepted.
    $accepted = legal_version_check($uid, $conditions['version'], $conditions['revision'], $legal_account);

    if ($accepted) {
      return;
    }
  }

  $form = legal_display_fields($conditions);

  $form['uid'] = array(
    '#type'  => 'value',
    '#value' => $uid,
  );

  $form['id_hash'] = array(
    '#type'  => 'value',
    '#value' => $id_hash,
  );

  $form['tc_id'] = array(
    '#type'  => 'value',
    '#value' => $conditions['tc_id'],
  );

  $form['version'] = array(
    '#type'  => 'value',
    '#value' => $conditions['version'],
  );

  $form['revision'] = array(
    '#type'  => 'value',
    '#value' => $conditions['revision'],
  );

  $form['language'] = array(
    '#type'  => 'value',
    '#value' => $conditions['language'],
  );

  $form = legal_display_changes($form, $uid);

  $form['save'] = array(
    '#type'  => 'submit',
    '#value' => t('Confirm'),
  );

  return $form;
}

function legal_login_validate($form, &$form_state) {
  $result = db_select('users', 'u')
    ->fields('u')
    ->condition('uid', $form_state['values']['uid'])
    ->range(0, 1)
    ->execute()
    ->fetchAllAssoc('uid');

  $account = array_pop($result);
  $id_hash = md5($account->name . $account->pass . $account->login);

  if ($id_hash != $form_state['values']['id_hash']) {
    form_set_error('legal_accept', t('User ID cannot be identified.'));
    drupal_goto();
  }
}

function legal_login_submit($form, &$form_state) {
  global $user;
  $values = $form_state['values'];
  $user   = user_load($values['uid']);

  $redirect = 'user/' . $user->uid;

  if (!empty($_GET['destination'])) {
    $redirect = $_GET['destination'];
  }

  $form_state['redirect'] = $redirect;

  legal_save_accept($values['version'], $values['revision'], $values['language'], $user->uid);
  watchdog('legal', '%name accepted T&C version %tc_id.', array('%name' => $user->name, '%tc_id' => $values['tc_id']));

  // Update the user table timestamp noting user has logged in.
  db_update('users')
    ->fields(array('login' => time()))
    ->condition('uid', $user->uid)
    ->execute();

  // User has new permissions, so we clear their menu cache.
  cache_clear_all($user->uid, 'cache_menu', TRUE);
  // Fixes login problems in Pressflow.
  drupal_session_regenerate();
  user_module_invoke('login', $edit, $user);
}

function theme_legal_login($variables) {
  $form = $variables['form'];
  $form = theme('legal_display', array('form' => $form));

  $output = '<p>' . t('To continue to use this site please read the Terms & Conditions below, and complete the form to confirm your acceptance.') . '</p>';

  if (isset($form['changes']['#value'])) {
    foreach (element_children($form['changes']) as $key) {
      $form['changes'][$key]['#prefix'] .= '<li>';
      $form['changes'][$key]['#suffix'] .= '</li>';
    }

    $form['changes']['start_list'] = array('#value' => '<ul>', '#weight' => 0);
    $form['changes']['end_list']   = array('#value' => '</ul>', '#weight' => 3);
    $output .= drupal_render($form['changes']);
  }

  $save = drupal_render($form['save']);
  $output .= drupal_render_children($form);
  $output .= $save;

  return $output;
}

function legal_get_accept($uid) {
  $keys   = array('legal_id', 'version', 'revision', 'language', 'uid', 'accepted');
  $result = db_select('legal_accepted', 'la')
    ->fields('la')
    ->condition('uid', $uid)
    ->orderBy('version', 'DESC')
    ->orderBy('revision', 'DESC')
    ->execute()
    ->fetchAllAssoc('legal_id');
  $result = count($result) ? array_shift($result) : array();

  $accept = array();

  foreach ($keys as $key) {
    if (isset($result->$key)) {
      $accept[$key] = $result->$key;
    }
  }

  return $accept;
}

function legal_save_accept($version, $revision, $language, $uid) {
  db_insert('legal_accepted')
    ->fields(array(
    'version'  => $version,
    'revision' => $revision,
    'language' => $language,
    'uid'      => $uid,
    'accepted' => time(),
  ))
    ->execute();
}

function legal_get_conditions($language = NULL) {
  $keys = array('tc_id', 'version', 'revision', 'language', 'conditions', 'date', 'extras', 'changes');

  if (!empty($language)) {
    $result = db_select('legal_conditions', 'lc')
      ->fields('lc')
      ->condition('language', $language)
      ->orderBy('version', 'DESC')
      ->orderBy('revision', 'DESC')
      ->range(0, 1)
      ->execute()
      ->fetchAllAssoc('tc_id');
    $result = (array)array_shift($result);
  }
  else {
    $result = db_select('legal_conditions', 'lc')
      ->fields('lc')
      ->orderBy('tc_id', 'DESC')
      ->execute()
      ->fetchAllAssoc('tc_id');
    $result = (array)array_shift($result);
  }

  foreach ($keys as $key) {
    $conditions[$key] = isset($result[$key]) ? $result[$key] : '';
  }

  $conditions['extras'] = empty($conditions['extras']) ? array() : unserialize($conditions['extras']);

  return $conditions;
}

/**
 * Get all changes since user last accepted.
 */
function legal_display_changes($form, $uid) {
  $is_list       = FALSE;
  $bullet_points = array();
  $last_accepted = legal_get_accept($uid);

  if (empty($last_accepted)) {
    return $form;
  }

  $result = db_select('legal_conditions', 'lc')
    ->fields('lc')
    ->condition(db_or()
      ->condition('version', $last_accepted['version'], '>')
      ->condition(db_and()
        ->condition('version', $last_accepted['version'])
        ->condition('revision', $last_accepted['revision'], '>')
    )
  )
    ->condition('language', $last_accepted['language'])
    ->orderBy('revision', 'ASC')
    ->orderBy('version', 'ASC')
    ->execute()
    ->fetchAllAssoc('tc_id');

  if (empty($result)) {
    return $form;
  }

  foreach ($result as $term) {

    $changes = filter_xss_admin($term->changes);

    if (!empty($changes)) {
      $bullet_points = array_merge($bullet_points, explode("\r\n", $changes));
    }
  }

  if (empty($bullet_points)) {
    return $form;
  }

  $form['changes'] = array(
    '#type'        => 'fieldset',
    '#title'       => t('Changes List'),
    '#description' => t('Changes to the Terms & Conditions since last accepted:'),
    '#collapsible' => TRUE,
    '#collapsed'   => TRUE,
    '#tree'        => TRUE,
  );

  $form['changes']['bullet_points'] = array(
    '#markup' => theme('item_list', array('items' => $bullet_points)),
  );

  return $form;
}

/**
 * Check if user has accepted latest version of T&C.
 */
function legal_version_check($uid, $version, $revision, $legal_account = array()) {
  $accepted = FALSE;

  if (empty($legal_account)) $legal_account = legal_get_accept($uid);

  if (array_key_exists('version', $legal_account) && array_key_exists('revision', $legal_account)) {
    if ($legal_account['version'] == $version && $legal_account['revision'] == $revision) {
      $accepted = TRUE;
    }
  }

  return $accepted;
}

/**
 * Access control callback.
 * Check that Locale module is enabled and user has access permission.
 */
function legal_languages_access($perm) {

  if (!module_exists('locale')) {
    return FALSE;
  }

  if (!user_access($perm)) {
    return FALSE;
  }

  return TRUE;
}

/**
 * Implements hook_views_api().
 */
function legal_views_api() {
  return array(
    'api'  => 2,
    'path' => drupal_get_path('module', 'legal') . '/views',
  );
}