/*
 * 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.systemui.pip;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Matrix;
import android.graphics.Rect;
import android.graphics.RectF;
import android.view.SurfaceControl;

import com.android.systemui.R;
import com.android.systemui.statusbar.policy.ConfigurationController;

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

/**
 * Abstracts the common operations on {@link SurfaceControl.Transaction} for PiP transition.
 */
@Singleton
public class PipSurfaceTransactionHelper implements ConfigurationController.ConfigurationListener {

    private final Context mContext;
    private final boolean mEnableCornerRadius;
    private int mCornerRadius;

    /** for {@link #scale(SurfaceControl.Transaction, SurfaceControl, Rect, Rect)} operation */
    private final Matrix mTmpTransform = new Matrix();
    private final float[] mTmpFloat9 = new float[9];
    private final RectF mTmpSourceRectF = new RectF();
    private final RectF mTmpDestinationRectF = new RectF();
    private final Rect mTmpDestinationRect = new Rect();

    @Inject
    public PipSurfaceTransactionHelper(Context context, ConfigurationController configController) {
        final Resources res = context.getResources();
        mContext = context;
        mEnableCornerRadius = res.getBoolean(R.bool.config_pipEnableRoundCorner);
        configController.addCallback(this);
    }

    @Override
    public void onDensityOrFontScaleChanged() {
        final Resources res = mContext.getResources();
        mCornerRadius = res.getDimensionPixelSize(R.dimen.pip_corner_radius);
    }

    /**
     * Operates the alpha on a given transaction and leash
     * @return same {@link PipSurfaceTransactionHelper} instance for method chaining
     */
    PipSurfaceTransactionHelper alpha(SurfaceControl.Transaction tx, SurfaceControl leash,
            float alpha) {
        tx.setAlpha(leash, alpha);
        return this;
    }

    /**
     * Operates the crop (and position) on a given transaction and leash
     * @return same {@link PipSurfaceTransactionHelper} instance for method chaining
     */
    PipSurfaceTransactionHelper crop(SurfaceControl.Transaction tx, SurfaceControl leash,
            Rect destinationBounds) {
        tx.setWindowCrop(leash, destinationBounds.width(), destinationBounds.height())
                .setPosition(leash, destinationBounds.left, destinationBounds.top);
        return this;
    }

    /**
     * Operates the scale (setMatrix) on a given transaction and leash
     * @return same {@link PipSurfaceTransactionHelper} instance for method chaining
     */
    PipSurfaceTransactionHelper scale(SurfaceControl.Transaction tx, SurfaceControl leash,
            Rect sourceBounds, Rect destinationBounds) {
        mTmpSourceRectF.set(sourceBounds);
        mTmpDestinationRectF.set(destinationBounds);
        mTmpTransform.setRectToRect(mTmpSourceRectF, mTmpDestinationRectF, Matrix.ScaleToFit.FILL);
        tx.setMatrix(leash, mTmpTransform, mTmpFloat9)
                .setPosition(leash, mTmpDestinationRectF.left, mTmpDestinationRectF.top);
        return this;
    }

    /**
     * Operates the scale (setMatrix) on a given transaction and leash
     * @return same {@link PipSurfaceTransactionHelper} instance for method chaining
     */
    PipSurfaceTransactionHelper scaleAndCrop(SurfaceControl.Transaction tx, SurfaceControl leash,
            Rect sourceBounds, Rect destinationBounds, Rect insets) {
        mTmpSourceRectF.set(sourceBounds);
        mTmpDestinationRect.set(sourceBounds);
        mTmpDestinationRect.inset(insets);
        // Scale by the shortest edge and offset such that the top/left of the scaled inset source
        // rect aligns with the top/left of the destination bounds
        final float scale = sourceBounds.width() <= sourceBounds.height()
                ? (float) destinationBounds.width() / sourceBounds.width()
                : (float) destinationBounds.height() / sourceBounds.height();
        final float left = destinationBounds.left - insets.left * scale;
        final float top = destinationBounds.top - insets.top * scale;
        mTmpTransform.setScale(scale, scale);
        tx.setMatrix(leash, mTmpTransform, mTmpFloat9)
                .setWindowCrop(leash, mTmpDestinationRect)
                .setPosition(leash, left, top);
        return this;
    }

    /**
     * Resets the scale (setMatrix) on a given transaction and leash if there's any
     * @return same {@link PipSurfaceTransactionHelper} instance for method chaining
     */
    PipSurfaceTransactionHelper resetScale(SurfaceControl.Transaction tx, SurfaceControl leash,
            Rect destinationBounds) {
        tx.setMatrix(leash, Matrix.IDENTITY_MATRIX, mTmpFloat9)
                .setPosition(leash, destinationBounds.left, destinationBounds.top);
        return this;
    }

    /**
     * Operates the round corner radius on a given transaction and leash
     * @return same {@link PipSurfaceTransactionHelper} instance for method chaining
     */
    PipSurfaceTransactionHelper round(SurfaceControl.Transaction tx, SurfaceControl leash,
            boolean applyCornerRadius) {
        if (mEnableCornerRadius) {
            tx.setCornerRadius(leash, applyCornerRadius ? mCornerRadius : 0);
        }
        return this;
    }

    interface SurfaceControlTransactionFactory {
        SurfaceControl.Transaction getTransaction();
    }
}