/*
 * Copyright (C) 2019 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.quickstep;

import static com.android.launcher3.ResourceUtils.INVALID_RESOURCE_HANDLE;
import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_NAVIGATION_MODE_2_BUTTON;
import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_NAVIGATION_MODE_3_BUTTON;
import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_NAVIGATION_MODE_GESTURE_BUTTON;
import static com.android.launcher3.util.PackageManagerHelper.getPackageFilter;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;

import com.android.launcher3.ResourceUtils;
import com.android.launcher3.logging.StatsLogManager.LauncherEvent;
import com.android.launcher3.util.MainThreadInitializedObject;

import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;

/**
 * Observer for the resource config that specifies the navigation bar mode.
 */
public class SysUINavigationMode {

    public enum Mode {
        THREE_BUTTONS(false, 0, LAUNCHER_NAVIGATION_MODE_3_BUTTON),
        TWO_BUTTONS(true, 1, LAUNCHER_NAVIGATION_MODE_2_BUTTON),
        NO_BUTTON(true, 2, LAUNCHER_NAVIGATION_MODE_GESTURE_BUTTON);

        public final boolean hasGestures;
        public final int resValue;
        public final LauncherEvent launcherEvent;

        Mode(boolean hasGestures, int resValue, LauncherEvent launcherEvent) {
            this.hasGestures = hasGestures;
            this.resValue = resValue;
            this.launcherEvent = launcherEvent;
        }
    }

    public static Mode getMode(Context context) {
        return INSTANCE.get(context).getMode();
    }

    public static final MainThreadInitializedObject<SysUINavigationMode> INSTANCE =
            new MainThreadInitializedObject<>(SysUINavigationMode::new);

    private static final String TAG = "SysUINavigationMode";
    private static final String ACTION_OVERLAY_CHANGED = "android.intent.action.OVERLAY_CHANGED";
    private static final String NAV_BAR_INTERACTION_MODE_RES_NAME =
            "config_navBarInteractionMode";
    private static final String TARGET_OVERLAY_PACKAGE = "android";

    private final Context mContext;
    private Mode mMode;

    private int mNavBarGesturalHeight;
    private int mNavBarLargerGesturalHeight;

    private final List<NavigationModeChangeListener> mChangeListeners =
            new CopyOnWriteArrayList<>();
    private final List<OneHandedModeChangeListener> mOneHandedOverlayChangeListeners =
            new ArrayList<>();

    public SysUINavigationMode(Context context) {
        mContext = context;
        initializeMode();

        mContext.registerReceiver(new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                updateMode();
                updateGesturalHeight();
            }
        }, getPackageFilter(TARGET_OVERLAY_PACKAGE, ACTION_OVERLAY_CHANGED));
    }

    /** Updates navigation mode when needed. */
    public void updateMode() {
        Mode oldMode = mMode;
        initializeMode();
        if (mMode != oldMode) {
            dispatchModeChange();
        }
    }

    private void updateGesturalHeight() {
        int newGesturalHeight = ResourceUtils.getDimenByName(
                ResourceUtils.NAVBAR_BOTTOM_GESTURE_SIZE, mContext.getResources(),
                INVALID_RESOURCE_HANDLE);

        if (newGesturalHeight == INVALID_RESOURCE_HANDLE) {
            Log.e(TAG, "Failed to get system resource ID. Incompatible framework version?");
            return;
        }

        if (mNavBarGesturalHeight != newGesturalHeight) {
            mNavBarGesturalHeight = newGesturalHeight;
        }

        int newLargerGesturalHeight = ResourceUtils.getDimenByName(
                ResourceUtils.NAVBAR_BOTTOM_GESTURE_LARGER_SIZE, mContext.getResources(),
                INVALID_RESOURCE_HANDLE);
        if (newLargerGesturalHeight == INVALID_RESOURCE_HANDLE) {
            Log.e(TAG, "Failed to get system resource ID. Incompatible framework version?");
            return;
        }
        if (mNavBarLargerGesturalHeight != newLargerGesturalHeight) {
            mNavBarLargerGesturalHeight = newLargerGesturalHeight;
            dispatchOneHandedOverlayChange();
        }
    }

    private void initializeMode() {
        int modeInt = ResourceUtils.getIntegerByName(NAV_BAR_INTERACTION_MODE_RES_NAME,
                mContext.getResources(), INVALID_RESOURCE_HANDLE);
        mNavBarGesturalHeight = ResourceUtils.getDimenByName(
                ResourceUtils.NAVBAR_BOTTOM_GESTURE_SIZE, mContext.getResources(),
                INVALID_RESOURCE_HANDLE);
        mNavBarLargerGesturalHeight = ResourceUtils.getDimenByName(
                ResourceUtils.NAVBAR_BOTTOM_GESTURE_LARGER_SIZE, mContext.getResources(),
                mNavBarGesturalHeight);

        if (modeInt == INVALID_RESOURCE_HANDLE) {
            Log.e(TAG, "Failed to get system resource ID. Incompatible framework version?");
            return;
        }

        for (Mode m : Mode.values()) {
            if (m.resValue == modeInt) {
                mMode = m;
            }
        }
    }

    private void dispatchModeChange() {
        for (NavigationModeChangeListener listener : mChangeListeners) {
            listener.onNavigationModeChanged(mMode);
        }
    }

    private void dispatchOneHandedOverlayChange() {
        for (OneHandedModeChangeListener listener : mOneHandedOverlayChangeListeners) {
            listener.onOneHandedModeChanged(mNavBarLargerGesturalHeight);
        }
    }

    public Mode addModeChangeListener(NavigationModeChangeListener listener) {
        mChangeListeners.add(listener);
        return mMode;
    }

    public void removeModeChangeListener(NavigationModeChangeListener listener) {
        mChangeListeners.remove(listener);
    }

    public int addOneHandedOverlayChangeListener(OneHandedModeChangeListener listener) {
        mOneHandedOverlayChangeListeners.add(listener);
        return mNavBarLargerGesturalHeight;
    }

    public void removeOneHandedOverlayChangeListener(OneHandedModeChangeListener listener) {
        mOneHandedOverlayChangeListeners.remove(listener);
    }

    public Mode getMode() {
        return mMode;
    }

    public void dump(PrintWriter pw) {
        pw.println("SysUINavigationMode:");
        pw.println("  mode=" + mMode.name());
        pw.println("  mNavBarGesturalHeight=:" + mNavBarGesturalHeight);
    }

    public interface NavigationModeChangeListener {
        void onNavigationModeChanged(Mode newMode);
    }

    public interface OneHandedModeChangeListener {
        void onOneHandedModeChanged(int newGesturalHeight);
    }
}