/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * 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.android.systemui.shortcut;

import static android.app.ActivityTaskManager.SPLIT_SCREEN_CREATE_MODE_BOTTOM_OR_RIGHT;
import static android.app.ActivityTaskManager.SPLIT_SCREEN_CREATE_MODE_TOP_OR_LEFT;

import android.content.Context;
import android.content.res.Configuration;
import android.os.RemoteException;
import android.view.IWindowManager;
import android.view.KeyEvent;
import android.view.WindowManagerGlobal;

import com.android.internal.policy.DividerSnapAlgorithm;
import com.android.systemui.SystemUI;
import com.android.systemui.recents.Recents;
import com.android.systemui.stackdivider.Divider;
import com.android.systemui.stackdivider.DividerView;

import javax.inject.Inject;
import javax.inject.Singleton;

/**
 * Dispatches shortcut to System UI components
 */
@Singleton
public class ShortcutKeyDispatcher extends SystemUI
        implements ShortcutKeyServiceProxy.Callbacks {

    private static final String TAG = "ShortcutKeyDispatcher";
    private final Divider mDivider;
    private final Recents mRecents;

    private ShortcutKeyServiceProxy mShortcutKeyServiceProxy = new ShortcutKeyServiceProxy(this);
    private IWindowManager mWindowManagerService = WindowManagerGlobal.getWindowManagerService();

    protected final long META_MASK = ((long) KeyEvent.META_META_ON) << Integer.SIZE;
    protected final long ALT_MASK = ((long) KeyEvent.META_ALT_ON) << Integer.SIZE;
    protected final long CTRL_MASK = ((long) KeyEvent.META_CTRL_ON) << Integer.SIZE;
    protected final long SHIFT_MASK = ((long) KeyEvent.META_SHIFT_ON) << Integer.SIZE;

    protected final long SC_DOCK_LEFT = META_MASK | KeyEvent.KEYCODE_LEFT_BRACKET;
    protected final long SC_DOCK_RIGHT = META_MASK | KeyEvent.KEYCODE_RIGHT_BRACKET;

    @Inject
    public ShortcutKeyDispatcher(Context context, Divider divider, Recents recents) {
        super(context);
        mDivider = divider;
        mRecents = recents;
    }

    /**
     * Registers a shortcut key to window manager.
     * @param shortcutCode packed representation of shortcut key code and meta information
     */
    public void registerShortcutKey(long shortcutCode) {
        try {
            mWindowManagerService.registerShortcutKey(shortcutCode, mShortcutKeyServiceProxy);
        } catch (RemoteException e) {
            // Do nothing
        }
    }

    @Override
    public void onShortcutKeyPressed(long shortcutCode) {
        int orientation = mContext.getResources().getConfiguration().orientation;
        if ((shortcutCode == SC_DOCK_LEFT || shortcutCode == SC_DOCK_RIGHT)
                && orientation == Configuration.ORIENTATION_LANDSCAPE) {
            handleDockKey(shortcutCode);
        }
    }

    @Override
    public void start() {
        registerShortcutKey(SC_DOCK_LEFT);
        registerShortcutKey(SC_DOCK_RIGHT);
    }

    private void handleDockKey(long shortcutCode) {
        if (mDivider == null || !mDivider.isDividerVisible()) {
            // Split the screen
            mRecents.splitPrimaryTask((shortcutCode == SC_DOCK_LEFT)
                    ? SPLIT_SCREEN_CREATE_MODE_TOP_OR_LEFT
                    : SPLIT_SCREEN_CREATE_MODE_BOTTOM_OR_RIGHT, null, -1);
        } else {
            // If there is already a docked window, we respond by resizing the docking pane.
            DividerView dividerView = mDivider.getView();
            DividerSnapAlgorithm snapAlgorithm = dividerView.getSnapAlgorithm();
            int dividerPosition = dividerView.getCurrentPosition();
            DividerSnapAlgorithm.SnapTarget currentTarget =
                    snapAlgorithm.calculateNonDismissingSnapTarget(dividerPosition);
            DividerSnapAlgorithm.SnapTarget target = (shortcutCode == SC_DOCK_LEFT)
                    ? snapAlgorithm.getPreviousTarget(currentTarget)
                    : snapAlgorithm.getNextTarget(currentTarget);
            dividerView.startDragging(true /* animate */, false /* touching */);
            dividerView.stopDragging(target.position, 0f, false /* avoidDismissStart */,
                    true /* logMetrics */);
        }
    }
}