/*
 * Copyright 2010 Daniel Kurka
 *
 * 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.googlecode.mgwt.ui.client;

import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
import com.google.gwt.dom.client.BodyElement;
import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.LinkElement;
import com.google.gwt.dom.client.MetaElement;
import com.google.gwt.dom.client.NodeList;
import com.google.gwt.dom.client.Style.Display;
import com.google.gwt.dom.client.Style.Float;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.dom.client.StyleInjector;
import com.google.gwt.event.logical.shared.CloseEvent;
import com.google.gwt.event.logical.shared.CloseHandler;
import com.google.gwt.event.logical.shared.ResizeEvent;
import com.google.gwt.event.logical.shared.ResizeHandler;
import com.google.gwt.event.shared.EventBus;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.event.shared.SimpleEventBus;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.Anchor;
import com.google.gwt.user.client.ui.RootPanel;
import com.googlecode.mgwt.dom.client.event.orientation.OrientationChangeEvent;
import com.googlecode.mgwt.dom.client.event.orientation.OrientationChangeEvent.ORIENTATION;
import com.googlecode.mgwt.dom.client.event.orientation.OrientationChangeHandler;
import com.googlecode.mgwt.ui.client.MGWTSettings.ViewPort;
import com.googlecode.mgwt.ui.client.theme.base.UtilCss;
import com.googlecode.mgwt.ui.client.util.AddressBarUtil;

/**
 * The MGWT Object is used to apply settings for an MGWT App. It also provides an instance of
 * {@link OsDetection}, as well a way to determine the device orientation
 *
 *
 *
 * @author Daniel Kurka
 */
public class MGWT {

  private static OsDetection OS_DETECTION;

  private static EventBus manager;

  private static ORIENTATION currentOrientation;
  private static Timer timer;

  private static boolean scrollingDisabled;
  private static JavaScriptObject nativeJsFunction;

  private static AddressBarUtil addressBarUtil;

  /**
   * Add a orientation handler to detect the device orientation
   *
   * @param handler the handler to add
   *          {@link com.googlecode.mgwt.dom.client.event.orientation.OrientationChangeHandler} .
   * @return a {@link com.google.gwt.event.shared.HandlerRegistration} object.
   */
  public static HandlerRegistration addOrientationChangeHandler(OrientationChangeHandler handler) {
    maybeSetupOrientation();
    return getManager().addHandler(OrientationChangeEvent.getType(), handler);
  }

  /**
   * Apply settings for this mgwt app. Every app should call this method with the options its wants
   * for their app
   *
   * The options are documented in @link {@link MGWTSettings}
   *
   * @param settings the settings for this app
   *
   */
  public static void applySettings(MGWTSettings settings) {

    // This is a very nasty workaround because GWT CssResource does not
    // support @media correctly!
    StyleInjector.inject(MGWTStyle.getTheme().getMGWTClientBundle().utilTextResource().getText());

    Element head = getHead();

    if (settings.getIconUrl() != null) {

      LinkElement iconUrlLinkElement = Document.get().createLinkElement();
      if (settings.isAddGlosToIcon()) {
        iconUrlLinkElement.setRel("apple-touch-startup-image");
      } else {
        iconUrlLinkElement.setRel("apple-touch-startup-image-precomposed");
      }

      iconUrlLinkElement.setHref(settings.getIconUrl());
      head.appendChild(iconUrlLinkElement);

    }

    if (settings.getStartUrl() != null) {
      LinkElement startUrlLinkElement = Document.get().createLinkElement();
      startUrlLinkElement.setRel("apple-touch-startup-image");
      startUrlLinkElement.setHref(settings.getStartUrl());
      head.appendChild(startUrlLinkElement);
    }

    ViewPort viewPort = settings.getViewPort();

    if (viewPort != null) {
      MetaElement fixViewPortElement = Document.get().createMetaElement();
      fixViewPortElement.setName("viewport");
      fixViewPortElement.setContent(viewPort.getContent());
      head.appendChild(fixViewPortElement);

    }

    if (settings.isFullscreen()) {
      MetaElement fullScreenMetaTag = Document.get().createMetaElement();
      fullScreenMetaTag.setName("apple-mobile-web-app-capable");
      fullScreenMetaTag.setContent("yes");
      head.appendChild(fullScreenMetaTag);

      if (settings.getStatusBar() != null) {
        MetaElement statusBarMetaTag = Document.get().createMetaElement();
        statusBarMetaTag.setName("apple-mobile-web-app-status-bar-style");
        statusBarMetaTag.setContent(settings.getStatusBar());
        head.appendChild(statusBarMetaTag);

      }

    }

    scrollingDisabled = settings.isPreventScrolling();
    if (settings.isPreventScrolling() && getOsDetection().isIOs()) {
      BodyElement body = Document.get().getBody();
      setupPreventScrolling(body);

    }

    if (settings.isDisablePhoneNumberDetection()) {
      MetaElement fullScreenMetaTag = Document.get().createMetaElement();
      fullScreenMetaTag.setName("format-detection");
      fullScreenMetaTag.setContent("telephone=no");
      head.appendChild(fullScreenMetaTag);
    }

    if (settings.getStatusBarStyle() != null) {
      MetaElement statusBarTag = Document.get().createMetaElement();
      statusBarTag.setName("apple-mobile-web-app-status-bar-style");
      switch (settings.getStatusBarStyle()) {

        case BLACK:
          statusBarTag.setContent("black");
          break;
        case BLACK_TRANSLUCENT:
          statusBarTag.setContent("black-translucent");
          break;
        case DEFAULT:
        default:
          statusBarTag.setContent("default");
          break;
      }

      head.appendChild(statusBarTag);
    }

  }

  /**
   * Detect if a web app is in full screen mode
   *
   * fullscreen currently only exits on ios
   *
   * @return true if the web app is in full screen mode, otherwise false
   */
  public static native boolean isFullScreen()/*-{
		if ($wnd.navigator.standalone) {
			return true;
		}
		return false;
  }-*/;

  /**
   *
   * Considered internal don`t call!
   * <p>
   * fixIOSScrollIssueBlur
   * </p>
   */
  // @edu.umd.cs.findbugs.annotations.SuppressWarnings(value = "LI_LAZY_INIT_UPDATE_STATIC", justification = "no multithreading in gwt code")
  public static void fixIOSScrollIssueBlur() {
    if (!scrollingDisabled) {
      return;
    }
    if (timer != null) {
      timer.cancel();

    }

    timer = new Timer() {

      @Override
      public void run() {
        Window.scrollTo(0, 0);

      }

    };

    timer.schedule(100);
  }

  /**
   * Considered internal don`t call!
   * <p>
   * fixIOSScrollIssueFocus
   * </p>
   */
  public static void fixIOSScrollIssueFocus() {
    if (!scrollingDisabled) {
      return;
    }
    if (timer != null) {
      timer.cancel();

    }
    timer = null;
  }

  /**
   * Get the os detection interface
   *
   * @return a {@link com.googlecode.mgwt.ui.client.OsDetection} object.
   */
  public static OsDetection getOsDetection() {
    if (OS_DETECTION == null) {
      OS_DETECTION = GWT.create(OsDetection.class);
    }
    return OS_DETECTION;
  }

  /**
   * Get the current orientation of the device
   *
   * @return the current orientation of the device
   */
  public static ORIENTATION getOrientation() {

    if (!orientationSupport()) {
      int height = Window.getClientHeight();
      int width = Window.getClientWidth();

      if (width > height) {
        return ORIENTATION.LANDSCAPE;
      } else {
        return ORIENTATION.PORTRAIT;
      }

    } else {
      int orientation = getOrientation0();

      ORIENTATION o;
      switch (orientation) {
        case 0:
        case 180:
          o = ORIENTATION.PORTRAIT;
          break;

        case 90:
        case -90:
          o = ORIENTATION.LANDSCAPE;
          break;

        default:
          throw new IllegalStateException("this should not happen!?");
      }

      return o;
    }

  }

  private static void fireOrientationChangedEvent(ORIENTATION orientation) {
    setClasses(orientation);
    getManager().fireEvent(new OrientationChangeEvent(orientation));
  }

  private static Element getHead() {
    NodeList<Element> elementsByTagName = Document.get().getElementsByTagName("head");

    if (elementsByTagName.getLength() != 1) {
      throw new RuntimeException("there is no head element");
    }

    return elementsByTagName.getItem(0);
  }

  private static native int getOrientation0()/*-{
		if (typeof ($wnd.orientation) == 'undefined') {
			return 0;
		}

		return $wnd.orientation;
  }-*/;

  private static void onorientationChange(int orientation) {

    ORIENTATION o;
    switch (orientation) {
      case 0:
      case 180:
        o = ORIENTATION.PORTRAIT;
        break;

      case 90:
      case -90:
        o = ORIENTATION.LANDSCAPE;
        break;

      default:
        o = ORIENTATION.PORTRAIT;
        break;
    }
    currentOrientation = o;
    fireOrientationChangedEvent(o);

  }

  // update styles on body
  private static void setClasses(ORIENTATION o) {
    UtilCss utilCss = MGWTStyle.getTheme().getMGWTClientBundle().getUtilCss();
    switch (o) {

      case PORTRAIT:
        Document.get().getBody().addClassName(utilCss.portrait());
        Document.get().getBody().removeClassName(utilCss.landscape());
        break;
      case LANDSCAPE:
        Document.get().getBody().addClassName(utilCss.landscape());
        Document.get().getBody().removeClassName(utilCss.portrait());
        break;

      default:
        break;
    }
  }

  private native static boolean orientationSupport()/*-{
		var ua = window.navigator.userAgent.toLowerCase();
		if (ua.indexOf('android') != -1) {
			return false;
		}
		if (ua.indexOf('iphone') != -1) {
			return true;
		}
		if (ua.indexOf('ipad') != -1) {
			return true;
		}

		return false;
  }-*/;

  private static boolean orientationInitialized;

  private static void maybeSetupOrientation() {
    if (orientationInitialized)
      return;
    if (!GWT.isClient()) {
      return;
    }

    if (!orientationSupport()) {
      Window.addResizeHandler(new ResizeHandler() {

        @Override
        public void onResize(ResizeEvent event) {
          ORIENTATION orientation = getOrientation();
          if (orientation != currentOrientation) {
            currentOrientation = orientation;
            fireOrientationChangedEvent(orientation);
          }
        }
      });
    } else {
      nativeJsFunction = setupOrientation0();
      Window.addCloseHandler(new CloseHandler<Window>() {

        @Override
        public void onClose(CloseEvent<Window> event) {
          destroyOrientation(nativeJsFunction);

        }
      });
    }

  }

  private static native JavaScriptObject setupOrientation0()/*-{

		var func = $entry(function() {
			@com.googlecode.mgwt.ui.client.MGWT::onorientationChange(I)($wnd.orientation);
		});
		$doc.body.onorientationchange = func;
		$doc.addEventListener("orientationChanged", func);
		return func;
  }-*/;

  private static native void destroyOrientation(JavaScriptObject o)/*-{
		$doc.body.onorientationchange = null;
		$doc.removeEventListener("orientationChanged", o);
  }-*/;

  private static native void setupPreventScrolling(Element el)/*-{
		var func = function(event) {
			event.preventDefault();
			return false;
		};

		el.ontouchmove = func;

  }-*/;

  /**
   * A utility method to hide the soft keyboard
   */
  public static void hideKeyBoard() {
    final Anchor anchor = new Anchor(" ");

    anchor.getElement().getStyle().setWidth(1, Unit.PX);
    anchor.getElement().getStyle().setHeight(1, Unit.PX);
    anchor.getElement().getStyle().setDisplay(Display.INLINE);
    anchor.getElement().getStyle().setFloat(Float.LEFT);

    RootPanel.get().add(anchor);
    anchor.setFocus(true);

    Scheduler.get().scheduleDeferred(new ScheduledCommand() {

      @Override
      public void execute() {
        anchor.removeFromParent();

      }
    });

  }

  public static void showAddressBar(boolean s) {
    if (s) {
      getAddressBarUtil().showAddressBar();
    } else {
      getAddressBarUtil().hideAddressBar();
    }
  }

  private static AddressBarUtil getAddressBarUtil() {
    if (addressBarUtil == null) {
      addressBarUtil = GWT.create(AddressBarUtil.class);
    }
    return addressBarUtil;
  }

  private static EventBus getManager() {
    if (manager == null) {
      manager = new SimpleEventBus();
    }
    return manager;
  }

}