packages/SystemUI/src/com/android/systemui/statusbar/MediaArtworkProcessor.kt

/*
 * 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.systemui.statusbar

import android.content.Context
import android.graphics.Bitmap
import android.graphics.Canvas
import android.graphics.Rect
import android.renderscript.Allocation
import android.renderscript.Element
import android.renderscript.RenderScript
import android.renderscript.ScriptIntrinsicBlur
import android.util.Log
import android.util.MathUtils
import android.util.Size
import android.view.WindowManager
import com.android.internal.annotations.VisibleForTesting
import com.android.internal.graphics.ColorUtils
import com.android.systemui.statusbar.notification.MediaNotificationProcessor
import javax.inject.Inject
import javax.inject.Singleton

private const val TAG = "MediaArtworkProcessor"
private const val COLOR_ALPHA = (255 * 0.7f).toInt()
private const val BLUR_RADIUS = 25f
private const val DOWNSAMPLE = 6

@Singleton
class MediaArtworkProcessor @Inject constructor() {

    private var mArtworkCache: Bitmap? = null

    fun processArtwork(context: Context, artwork: Bitmap, windowType: Int): Bitmap? {
        if (mArtworkCache != null) {
            return mArtworkCache
        }
        val renderScript = RenderScript.create(context)
        val blur = ScriptIntrinsicBlur.create(renderScript, Element.U8_4(renderScript))
        var input: Allocation? = null
        var output: Allocation? = null
        var inBitmap: Bitmap? = null
        try {
            val size = getWindowSize(context, windowType)
            val rect = Rect(0, 0, artwork.width, artwork.height)
            MathUtils.fitRect(rect, Math.max(size.width / DOWNSAMPLE, size.height / DOWNSAMPLE))
            inBitmap = Bitmap.createScaledBitmap(artwork, rect.width(), rect.height(),
                    true /* filter */)
            // Render script blurs only support ARGB_8888, we need a conversion if we got a
            // different bitmap config.
            if (inBitmap.config != Bitmap.Config.ARGB_8888) {
                val oldIn = inBitmap
                inBitmap = oldIn.copy(Bitmap.Config.ARGB_8888, false /* isMutable */)
                oldIn.recycle()
            }
            val outBitmap = Bitmap.createBitmap(inBitmap.width, inBitmap.height,
                    Bitmap.Config.ARGB_8888)

            input = Allocation.createFromBitmap(renderScript, inBitmap,
                    Allocation.MipmapControl.MIPMAP_NONE, Allocation.USAGE_GRAPHICS_TEXTURE)
            output = Allocation.createFromBitmap(renderScript, outBitmap)

            blur.setRadius(BLUR_RADIUS)
            blur.setInput(input)
            blur.forEach(output)
            output.copyTo(outBitmap)

            val swatch = MediaNotificationProcessor.findBackgroundSwatch(artwork)

            val canvas = Canvas(outBitmap)
            canvas.drawColor(ColorUtils.setAlphaComponent(swatch.rgb, COLOR_ALPHA))
            return outBitmap
        } catch (ex: IllegalArgumentException) {
            Log.e(TAG, "error while processing artwork", ex)
            return null
        } finally {
            input?.destroy()
            output?.destroy()
            blur.destroy()
            inBitmap?.recycle()
        }
    }

    fun clearCache() {
        mArtworkCache?.recycle()
        mArtworkCache = null
    }

    @VisibleForTesting
    internal fun getWindowSize(context: Context, windowType: Int): Size {
        val windowContext = context.display?.let {
            context.createDisplayContext(it)
                    .createWindowContext(windowType, null)
        } ?: run { throw NullPointerException("Display is null") }
        val windowManager = windowContext.getSystemService(WindowManager::class.java)
                ?: run { throw NullPointerException("Null window manager") }
        return windowManager.currentWindowMetrics.size
    }
}