<?php

/**
 * @file
 * Back To Top link using JQuery.
 *
 * Requires javascript as enabled.
 */

/**
 * Shows Back To Top on every page except the listed pages.
 */
define('BACK_TO_TOP_VISIBILITY_NOTLISTED', 0);

/**
 * Shows Back To Top on only the listed pages.
 */
define('BACK_TO_TOP_VISIBILITY_LISTED', 1);

/**
 * Implements hook_page_menu().
 */
function back_to_top_menu() {
  $items = array();

  $items['admin/config/user-interface/back_to_top'] = array(
    'title' => 'Back To Top',
    'description' => 'Administer Back To Top settings',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('back_to_top_settings'),
    'access arguments' => array('access back_to_top settings'),
    'file' => 'back_to_top.admin.inc',
    'type' => MENU_NORMAL_ITEM,
  );

  return $items;
}

/**
 * Implements hook_page_build().
 *
 * Add javascript & css but first check if prevent on mobile
 */
function back_to_top_page_build() {
  $settings = array(
    'back_to_top_button_text' => variable_get('back_to_top_button_text', 'Back to top'),
  );
  if (variable_get('back_to_top_prevent_on_mobile', 'TRUE') && (is_mobile())) {
    return FALSE;
  }
  if (variable_get('back_to_top_prevent_on_non_mobile', 'FALSE') && (!is_mobile())) {
    return FALSE;
  }
  if (variable_get('back_to_top_prevent_in_admin', 'TRUE') && (is_adminpage())) {
    return FALSE;
  }
  if (variable_get('back_to_top_prevent_in_front', 'FALSE') && (drupal_is_front_page())) {
    return FALSE;
  }
  $pages = drupal_strtolower(variable_get('back_to_top_pages', ''));
  $visibility = (int) variable_get('back_to_top_visibility', BACK_TO_TOP_VISIBILITY_NOTLISTED);
  $path = drupal_strtolower(drupal_get_path_alias($_GET['q']));
  $page_match = drupal_match_path($path, $pages);
  // Compare the lowercase internal and lowercase path alias (if any).
  $page_match = drupal_match_path($path, $pages);
  if ($path != $_GET['q']) {
    $page_match = $page_match || drupal_match_path($_GET['q'], $pages);
  }
  $page_match = !($visibility xor $page_match);

  if (!$page_match) {
    return FALSE;
  }

  drupal_add_library('system', 'effects');
  $settings['#attached']['library'][] = array('system', 'ui');

  drupal_add_js(drupal_get_path('module', 'back_to_top') . '/js/back_to_top.js', array(
    'group' => JS_DEFAULT,
    'every_page' => TRUE,
  ));

  drupal_add_js(array('back_to_top' => array('back_to_top_button_trigger' => variable_get('back_to_top_button_trigger', 100))), 'setting');

  // Add stylesheet for image or text/css button.
  if ((variable_get('back_to_top_button_type', 'image')) == "text") {
    drupal_add_css(drupal_get_path('module', 'back_to_top') . '/css/back_to_top_text.css', array(
      'group' => CSS_DEFAULT,
      'every_page' => TRUE,
    ));
  }
  else {
    drupal_add_css(drupal_get_path('module', 'back_to_top') . '/css/back_to_top.css', array(
      'group' => CSS_DEFAULT,
      'every_page' => TRUE,
    ));
  }

  // Check variables and add placement.
  if ((variable_get('back_to_top_button_place', '1')) == 2) {
    $css = "#backtotop { left: 10px; }";
    drupal_add_css($css, 'inline');
  }
  if ((variable_get('back_to_top_button_place', '1')) == 3) {
    $css = "#backtotop { left: 50%; margin-left: -50px; }";
    drupal_add_css($css, 'inline');
  }
  if ((variable_get('back_to_top_button_place', '1')) == 4) {
    $css = "#backtotop { top: 10px; }";
    drupal_add_css($css, 'inline');
  }
  if ((variable_get('back_to_top_button_place', '1')) == 5) {
    $css = "#backtotop { top: 10px; left: 10px; }";
    drupal_add_css($css, 'inline');
  }
  if ((variable_get('back_to_top_button_place', '1')) == 6) {
    $css = "#backtotop { top: 10px; left: 50%; margin-left: -50px; }";
    drupal_add_css($css, 'inline');
  }
  if ((variable_get('back_to_top_button_place', '1')) == 7) {
    $css = "#backtotop { top: 50%; }";
    drupal_add_css($css, 'inline');
  }
  if ((variable_get('back_to_top_button_place', '1')) == 8) {
    $css = "#backtotop { top: 50%; left: 10px; }";
    drupal_add_css($css, 'inline');
  }
  if ((variable_get('back_to_top_button_place', '1')) == 9) {
    $css = "#backtotop { top: 50%; left: 50%; margin-left: -50px; }";
    drupal_add_css($css, 'inline');
  }
  // Check variables and add color from settings
  // this code could be done a bit nicer.
  if (((variable_get('back_to_top_button_type', 'image')) == "text") && ((variable_get('back_to_top_bg_color', '#F7F7F7')) !== '#F7F7F7')) {
    $setting = variable_get('back_to_top_bg_color', '#F7F7F7');
    $css = "#backtotop { background: " . $setting . "; }";
    drupal_add_css($css, 'inline');
  }
  if (((variable_get('back_to_top_button_type', 'image')) == "text") && ((variable_get('back_to_top_border_color', '#CCCCCC')) !== '#CCCCCC')) {
    $setting = variable_get('back_to_top_bg_color', '#CCCCCC');
    $css = "#backtotop { border-color: " . $setting . "; }";
    drupal_add_css($css, 'inline');
  }
  if (((variable_get('back_to_top_button_type', 'image')) == "text") && ((variable_get('back_to_top_hover_color', '#EEEEEE')) !== '#EEEEEE')) {
    $setting = variable_get('back_to_top_hover_color', '#EEEEEE');
    $css = "#backtotop:hover { background: " . $setting . "; border-color: " . $setting . "; }";
    drupal_add_css($css, 'inline');
  }
  if (((variable_get('back_to_top_button_type', 'image')) == "text") && ((variable_get('back_to_top_text_color', '#333333')) !== '#333333')) {
    $setting = variable_get('back_to_top_text_color', '#333333');
    $css = "#backtotop { color: " . $setting . "; }";
    drupal_add_css($css, 'inline');
  }
  // Add settings to js.
  drupal_add_js(array('back_to_top' => $settings), 'setting');
}

/**
 * Check if mobile or touch device with PHP so javascript and css isn't
 * included in that case.
 */
function is_mobile() {

  // Check for mobile device using Browscap module if it is available.
  if (module_exists('browscap')) {
    $browser = browscap_get_browser();
    if (isset($browser['ismobiledevice']) && $browser['ismobiledevice'] == 1) {
      return TRUE;
    }
  }

  if (isset($_SERVER["HTTP_X_WAP_PROFILE"])) {
    return TRUE;
  }
  if (isset($_SERVER["HTTP_ACCEPT"]) && preg_match("/wap\.|\.wap/i", $_SERVER["HTTP_ACCEPT"])) {
    return TRUE;
  }
  if (isset($_SERVER["HTTP_USER_AGENT"])) {
    $user_agents = array(
      "midp",
      "j2me",
      "iphone",
      "avantg",
      "docomo",
      "novarra",
      "palmos",
      "palmsource",
      "240x320",
      "opwv",
      "chtml",
      "pda",
      "windows\ ce",
      "mmp\/",
      "blackberry",
      "mib\/",
      "symbian",
      "wireless",
      "nokia",
      "hand",
      "mobi",
      "phone",
      "cdm",
      "up\.b",
      "audio",
      "sie\-",
      "sec\-",
      "samsung",
      "htc",
      "mot\-",
      "mitsu",
      "sagem",
      "sony",
      "alcatel",
      "lg",
      "erics",
      "vx",
      "^nec",
      "philips",
      "mmm",
      "xx",
      "panasonic",
      "sharp",
      "wap",
      "sch",
      "rover",
      "pocket",
      "benq",
      "java",
      "pt",
      "pg",
      "vox",
      "amoi",
      "bird",
      "compal",
      "kg",
      "voda",
      "sany",
      "kdd",
      "dbt",
      "sendo",
      "sgh",
      "gradi",
      "jb",
      "\d\d\di",
      "moto",
      "ipad",
      "android",
      "ipod",
      "webos",
    );

    foreach ($user_agents as $user_string) {
      if (preg_match("/" . $user_string . "/i", strtolower($_SERVER["HTTP_USER_AGENT"]))) {
        return TRUE;
      }
    }
  }
  return FALSE;
}

/**
 * Check if page viewed is in admin section or a node/edit for possible option
 * to not include javascript and css in that case.
 */
function is_adminpage() {
  return path_is_admin(current_path());
}

/**
 * Implements hook_permission().
 */
function back_to_top_permission() {
  return array(
    'access back_to_top settings' => array(
      'title' => t('Access Back to top settings'),
      'description' => t('Access Back to top settings.'),
    ),
  );
}

/**
 * Implements hook_install().
 *
 * Add default permission for access settings to administrator
 */
function back_to_top_install() {
  // rid=3 => administrator.
  user_role_change_permissions(3,
    array(
      'access back_to_top settings' => TRUE,
    )
  );
}