// Copyright (c) 2010 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// TODO(arv): Move to shared/js once namespaced and tested.

var global = this;
const IS_MAC = /^Mac/.test(navigator.platform);

function $(id) {
  return document.getElementById(id);
}

function url(s) {
  // http://www.w3.org/TR/css3-values/#uris
  // Parentheses, commas, whitespace characters, single quotes (') and double
  // quotes (") appearing in a URI must be escaped with a backslash
  var s2 = s.replace(/(\(|\)|\,|\s|\'|\"|\\)/g, '\\$1');
  // WebKit has a bug when it comes to URLs that end with \
  // https://bugs.webkit.org/show_bug.cgi?id=28885
  if (/\\\\$/.test(s2)) {
    // Add a space to work around the WebKit bug.
    s2 += ' ';
  }
  return 'url("' + s2 + '")';
}

function findAncestorByClass(el, className) {
  return findAncestor(el, function(el) {
    if (el.classList)
      return el.classList.contains(className);
    return null;
  });
}

/**
 * Return the first ancestor for which the {@code predicate} returns true.
 * @param {Node} node The node to check.
 * @param {function(Node) : boolean} predicate The function that tests the
 *     nodes.
 * @return {Node} The found ancestor or null if not found.
 */
function findAncestor(node, predicate) {
  var last = false;
  while (node != null && !(last = predicate(node))) {
    node = node.parentNode;
  }
  return last ? node : null;
}

function swapDomNodes(a, b) {
  var afterA = a.nextSibling;
  if (afterA == b) {
    swapDomNodes(b, a);
    return;
  }
  var aParent = a.parentNode;
  b.parentNode.replaceChild(a, b);
  aParent.insertBefore(b, afterA);
}

/**
 * Calls chrome.send with a callback and restores the original afterwards.
 */
function chromeSend(name, params, callbackName, callback) {
  var old = global[callbackName];
  global[callbackName] = function() {
    // restore
    global[callbackName] = old;

    var args = Array.prototype.slice.call(arguments);
    return callback.apply(global, args);
  };
  chrome.send(name, params);
}