// Copyright 2012 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.collide.client.util;

import com.google.collide.shared.util.StringUtils;
import com.google.gwt.core.client.GWT;
import com.google.gwt.user.client.Window;

/**
 * Utility methods relating to the browser.
 */
public abstract class BrowserUtils {

  private static final BrowserUtils INSTANCE = GWT.create(BrowserUtils.class);

  abstract boolean isFFox();

  static class Chrome extends BrowserUtils {
    Chrome() {
    }

    @Override
    boolean isFFox() {
      return false;
    }
  }

  static class Firefox extends BrowserUtils {
    Firefox() {
    }

    @Override
    boolean isFFox() {
      return true;
    }
  }

  public static boolean isFirefox() {
    return INSTANCE.isFFox();
  }

  public static boolean isChromeOs() {
    return Window.Navigator.getUserAgent().contains(" CrOS ");
  }

  public static boolean hasUrlParameter(String parameter) {
    return Window.Location.getParameter(parameter) != null;
  }

  public static boolean hasUrlParameter(String parameter, String value) {
    return StringUtils.equalNonEmptyStrings(Window.Location.getParameter(parameter), value);
  }

  private BrowserUtils() {
  }
}