/*
 * Copyright (C) 2020 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.launcher3.statehandlers;

import static com.android.app.animation.Interpolators.LINEAR;
import static com.android.launcher3.states.StateAnimationConfig.ANIM_DEPTH;
import static com.android.launcher3.states.StateAnimationConfig.SKIP_DEPTH_CONTROLLER;
import static com.android.launcher3.util.Executors.UI_HELPER_EXECUTOR;
import static com.android.launcher3.util.MultiPropertyFactory.MULTI_PROPERTY_VALUE;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.ObjectAnimator;
import android.view.CrossWindowBlurListeners;
import android.view.View;
import android.view.ViewRootImpl;
import android.view.ViewTreeObserver;

import androidx.annotation.VisibleForTesting;

import com.android.launcher3.BaseActivity;
import com.android.launcher3.Launcher;
import com.android.launcher3.LauncherState;
import com.android.launcher3.anim.PendingAnimation;
import com.android.launcher3.statemanager.StateManager.StateHandler;
import com.android.launcher3.states.StateAnimationConfig;
import com.android.quickstep.util.BaseDepthController;

import java.io.PrintWriter;
import java.util.function.Consumer;

/**
 * Controls blur and wallpaper zoom, for the Launcher surface only.
 */
public class DepthController extends BaseDepthController implements StateHandler<LauncherState>,
        BaseActivity.MultiWindowModeChangedListener {
    @VisibleForTesting
    final ViewTreeObserver.OnDrawListener mOnDrawListener = this::onLauncherDraw;

    private final Consumer<Boolean> mCrossWindowBlurListener = this::setCrossWindowBlursEnabled;

    private final Runnable mOpaquenessListener = this::applyDepthAndBlur;

    // Workaround for animating the depth when multiwindow mode changes.
    private boolean mIgnoreStateChangesDuringMultiWindowAnimation = false;

    private View.OnAttachStateChangeListener mOnAttachListener;

    // Ensure {@link mOnDrawListener} is added only once to avoid spamming DragLayer's mRunQueue
    // via {@link View#post(Runnable)}
    private boolean mIsOnDrawListenerAdded = false;

    public DepthController(Launcher l) {
        super(l);
    }

    private void onLauncherDraw() {
        View view = mLauncher.getDragLayer();
        ViewRootImpl viewRootImpl = view.getViewRootImpl();
        setBaseSurface(viewRootImpl != null ? viewRootImpl.getSurfaceControl() : null);
        view.post(this::removeOnDrawListener);
    }

    private void ensureDependencies() {
        View rootView = mLauncher.getRootView();
        if (rootView == null) {
            return;
        }
        if (mOnAttachListener != null) {
            return;
        }
        mOnAttachListener = new View.OnAttachStateChangeListener() {
            @Override
            public void onViewAttachedToWindow(View view) {
                UI_HELPER_EXECUTOR.execute(() ->
                        CrossWindowBlurListeners.getInstance().addListener(
                                mLauncher.getMainExecutor(), mCrossWindowBlurListener));
                mLauncher.getScrimView().addOpaquenessListener(mOpaquenessListener);

                // To handle the case where window token is invalid during last setDepth call.
                applyDepthAndBlur();
            }

            @Override
            public void onViewDetachedFromWindow(View view) {
                removeSecondaryListeners();
            }
        };
        rootView.addOnAttachStateChangeListener(mOnAttachListener);
        if (rootView.isAttachedToWindow()) {
            mOnAttachListener.onViewAttachedToWindow(rootView);
        }
    }

    /**
     * Cleans up after this controller so it can be garbage collected without leaving traces.
     */
    public void dispose() {
        removeSecondaryListeners();

        if (mLauncher.getRootView() != null && mOnAttachListener != null) {
            mLauncher.getRootView().removeOnAttachStateChangeListener(mOnAttachListener);
            mOnAttachListener = null;
        }
    }

    private void removeSecondaryListeners() {
        UI_HELPER_EXECUTOR.execute(() ->
                CrossWindowBlurListeners.getInstance()
                        .removeListener(mCrossWindowBlurListener));
        if (mOpaquenessListener != null) {
            mLauncher.getScrimView().removeOpaquenessListener(mOpaquenessListener);
        }
    }

    /**
     * Sets if the underlying activity is started or not
     */
    public void setActivityStarted(boolean isStarted) {
        if (isStarted) {
            addOnDrawListener();
        } else {
            removeOnDrawListener();
            setBaseSurface(null);
        }
    }

    @Override
    public void setState(LauncherState toState) {
        if (mIgnoreStateChangesDuringMultiWindowAnimation) {
            return;
        }

        stateDepth.setValue(toState.getDepth(mLauncher));
        if (toState == LauncherState.BACKGROUND_APP) {
            addOnDrawListener();
        }
    }

    @Override
    public void setStateWithAnimation(LauncherState toState, StateAnimationConfig config,
            PendingAnimation animation) {
        if (config.hasAnimationFlag(SKIP_DEPTH_CONTROLLER)
                || mIgnoreStateChangesDuringMultiWindowAnimation) {
            return;
        }

        float toDepth = toState.getDepth(mLauncher);
        animation.setFloat(stateDepth, MULTI_PROPERTY_VALUE, toDepth,
                config.getInterpolator(ANIM_DEPTH, LINEAR));
    }

    @Override
    protected void applyDepthAndBlur() {
        ensureDependencies();
        super.applyDepthAndBlur();
    }

    @Override
    protected void onInvalidSurface() {
        // Lets wait for surface to become valid again
        addOnDrawListener();
    }

    private void addOnDrawListener() {
        if (mIsOnDrawListenerAdded) {
            return;
        }
        mLauncher.getDragLayer().getViewTreeObserver().addOnDrawListener(mOnDrawListener);
        mIsOnDrawListenerAdded = true;
    }

    private void removeOnDrawListener() {
        if (!mIsOnDrawListenerAdded) {
            return;
        }
        mLauncher.getDragLayer().getViewTreeObserver().removeOnDrawListener(mOnDrawListener);
        mIsOnDrawListenerAdded = false;
    }

    @Override
    public void onMultiWindowModeChanged(boolean isInMultiWindowMode) {
        mIgnoreStateChangesDuringMultiWindowAnimation = true;

        ObjectAnimator mwAnimation = ObjectAnimator.ofFloat(stateDepth, MULTI_PROPERTY_VALUE,
                mLauncher.getStateManager().getState().getDepth(mLauncher, isInMultiWindowMode))
                .setDuration(300);
        mwAnimation.addListener(new AnimatorListenerAdapter() {
            @Override
            public void onAnimationEnd(Animator animation) {
                mIgnoreStateChangesDuringMultiWindowAnimation = false;
            }
        });
        mwAnimation.setAutoCancel(true);
        mwAnimation.start();
    }

    public void dump(String prefix, PrintWriter writer) {
        writer.println(prefix + "DepthController");
        writer.println(prefix + "\tmMaxBlurRadius=" + mMaxBlurRadius);
        writer.println(prefix + "\tmCrossWindowBlursEnabled=" + mCrossWindowBlursEnabled);
        writer.println(prefix + "\tmBaseSurface=" + mBaseSurface);
        writer.println(prefix + "\tmBaseSurfaceOverride=" + mBaseSurfaceOverride);
        writer.println(prefix + "\tmStateDepth=" + stateDepth.getValue());
        writer.println(prefix + "\tmWidgetDepth=" + widgetDepth.getValue());
        writer.println(prefix + "\tmCurrentBlur=" + mCurrentBlur);
        writer.println(prefix + "\tmInEarlyWakeUp=" + mInEarlyWakeUp);
        writer.println(prefix + "\tmIgnoreStateChangesDuringMultiWindowAnimation="
                + mIgnoreStateChangesDuringMultiWindowAnimation);
        writer.println(prefix + "\tmPauseBlurs=" + mPauseBlurs);
        writer.println(prefix + "\tmWaitingOnSurfaceValidity=" + mWaitingOnSurfaceValidity);
    }
}