/*
 * Copyright (C) 2023 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.test.silkfx.hdr

import android.content.Context
import android.graphics.Bitmap
import android.graphics.Canvas
import android.graphics.ColorMatrixColorFilter
import android.graphics.Gainmap
import android.graphics.ImageDecoder
import android.graphics.Paint
import android.util.AttributeSet
import android.view.View
import android.widget.AdapterView
import android.widget.ArrayAdapter
import android.widget.Button
import android.widget.FrameLayout
import android.widget.RadioGroup
import android.widget.Spinner
import android.widget.TextView
import com.android.test.silkfx.R
import com.davemorrissey.labs.subscaleview.ImageSource
import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView

class GainmapImage(context: Context, attrs: AttributeSet?) : FrameLayout(context, attrs) {

    private val gainmapImages: Array<String>
    private var selectedImage = -1
    private var outputMode = R.id.output_hdr
    private var bitmap: Bitmap? = null
    private var originalGainmap: Gainmap? = null
    private var gainmapVisualizer: Bitmap? = null
    private lateinit var imageView: SubsamplingScaleImageView
    private lateinit var gainmapMetadataEditor: GainmapMetadataEditor

    init {
        gainmapImages = context.assets.list("gainmaps")!!
    }

    fun setImageSource(source: ImageDecoder.Source) {
        findViewById<Spinner>(R.id.image_selection)!!.visibility = View.GONE
        doDecode(source)
    }

    override fun onFinishInflate() {
        super.onFinishInflate()

        imageView = findViewById(R.id.image)!!
        gainmapMetadataEditor = GainmapMetadataEditor(this, imageView)

        findViewById<RadioGroup>(R.id.output_mode)!!.also {
            it.check(outputMode)
            it.setOnCheckedChangeListener { _, checkedId ->
                outputMode = checkedId
                updateDisplay()
            }
        }

        val spinner = findViewById<Spinner>(R.id.image_selection)!!
        val adapter = ArrayAdapter(context, android.R.layout.simple_spinner_item, gainmapImages)
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item)
        spinner.adapter = adapter
        spinner.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
            override fun onItemSelected(
                    parent: AdapterView<*>?,
                    view: View?,
                    position: Int,
                    id: Long
            ) {
                setImage(position)
            }

            override fun onNothingSelected(parent: AdapterView<*>?) {
            }
        }

        findViewById<Button>(R.id.gainmap_metadata)!!.setOnClickListener {
            gainmapMetadataEditor.openEditor()
        }

        setImage(0)

        imageView.apply {
            isClickable = true
            setOnClickListener {
                animate().alpha(.5f).withEndAction {
                    animate().alpha(1f).start()
                }.start()
            }
        }
    }

    private fun setImage(position: Int) {
        if (selectedImage == position) return
        selectedImage = position
        val source = ImageDecoder.createSource(resources.assets,
                "gainmaps/${gainmapImages[position]}")
        doDecode(source)
    }

    private fun doDecode(source: ImageDecoder.Source) {
        originalGainmap = null
        bitmap = ImageDecoder.decodeBitmap(source) { decoder, info, source ->
            decoder.allocator = ImageDecoder.ALLOCATOR_SOFTWARE
        }
        if (!bitmap!!.hasGainmap()) {
            outputMode = R.id.output_sdr
            findViewById<TextView>(R.id.error_msg)!!.also {
                it.visibility = View.VISIBLE
                it.text = "Image doesn't have a gainmap, only showing in SDR"
            }
            findViewById<RadioGroup>(R.id.output_mode)!!.also {
                it.check(R.id.output_sdr)
                it.visibility = View.GONE
            }
        } else {
            findViewById<TextView>(R.id.error_msg)!!.visibility = View.GONE
            findViewById<RadioGroup>(R.id.output_mode)!!.visibility = View.VISIBLE

            val gainmap = bitmap!!.gainmap!!
            originalGainmap = gainmap
            gainmapMetadataEditor.setGainmap(Gainmap(gainmap, gainmap.gainmapContents))
            val map = gainmap.gainmapContents
            if (map.config != Bitmap.Config.ALPHA_8) {
                gainmapVisualizer = map
            } else {
                gainmapVisualizer = Bitmap.createBitmap(map.width, map.height,
                        Bitmap.Config.ARGB_8888)
                val canvas = Canvas(gainmapVisualizer!!)
                val paint = Paint()
                paint.colorFilter = ColorMatrixColorFilter(
                        floatArrayOf(
                                0f, 0f, 0f, 1f, 0f,
                                0f, 0f, 0f, 1f, 0f,
                                0f, 0f, 0f, 1f, 0f,
                                0f, 0f, 0f, 0f, 255f
                        )
                )
                canvas.drawBitmap(map, 0f, 0f, paint)
                canvas.setBitmap(null)
            }
        }

        updateDisplay()
    }

    private fun updateDisplay() {
        if (bitmap == null) return

        imageView.setImage(ImageSource.cachedBitmap(when (outputMode) {
            R.id.output_hdr -> {
                bitmap!!.gainmap = originalGainmap
                bitmap!!
            }

            R.id.output_hdr_test -> {
                bitmap!!.gainmap = gainmapMetadataEditor.editedGainmap()
                bitmap!!
            }

            R.id.output_sdr -> {
                bitmap!!.gainmap = null; bitmap!!
            }

            R.id.output_gainmap -> gainmapVisualizer!!
            else -> throw IllegalStateException()
        }))
    }
}