/*
 * 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.wallpaper.testing

import android.graphics.Bitmap
import com.android.wallpaper.picker.customization.data.content.WallpaperClient
import com.android.wallpaper.picker.customization.shared.model.WallpaperDestination
import com.android.wallpaper.picker.customization.shared.model.WallpaperModel
import kotlin.math.min
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.flow.map

class FakeWallpaperClient : WallpaperClient {

    private val _recentWallpapers =
        MutableStateFlow(
            buildMap {
                WallpaperDestination.values()
                    .filter { it != WallpaperDestination.BOTH }
                    .forEach { screen -> put(screen, INITIAL_RECENT_WALLPAPERS) }
            }
        )
    private var isPaused = false
    private var deferred = mutableListOf<(suspend () -> Unit)>()

    fun setRecentWallpapers(
        recentWallpapersByDestination: Map<WallpaperDestination, List<WallpaperModel>>,
    ) {
        _recentWallpapers.value = recentWallpapersByDestination
    }

    fun pause() {
        isPaused = true
    }

    suspend fun unpause() {
        isPaused = false
        deferred.forEach { it.invoke() }
        deferred.clear()
    }

    override fun recentWallpapers(
        destination: WallpaperDestination,
        limit: Int,
    ): Flow<List<WallpaperModel>> {
        return _recentWallpapers.map { wallpapersByScreen ->
            val wallpapers =
                wallpapersByScreen[destination] ?: error("No wallpapers for screen $destination")
            if (wallpapers.size > limit) {
                wallpapers.subList(0, min(limit, wallpapers.size))
            } else {
                wallpapers
            }
        }
    }

    fun getCurrentWallpaper(
        destination: WallpaperDestination,
    ): WallpaperModel {
        return _recentWallpapers.value[destination]?.get(0)
            ?: error("No wallpapers for screen $destination")
    }

    override suspend fun setWallpaper(
        destination: WallpaperDestination,
        wallpaperId: String,
        onDone: () -> Unit
    ) {
        if (isPaused) {
            deferred.add { setWallpaper(destination, wallpaperId, onDone) }
        } else {
            _recentWallpapers.value =
                _recentWallpapers.value.toMutableMap().apply {
                    this[destination] =
                        _recentWallpapers.value[destination]?.sortedBy {
                            it.wallpaperId != wallpaperId
                        }
                            ?: error("No wallpapers for screen $destination")
                }
            onDone.invoke()
        }
    }

    override suspend fun loadThumbnail(wallpaperId: String): Bitmap? {
        return Bitmap.createBitmap(1, 1, Bitmap.Config.ARGB_8888)
    }

    override fun areRecentsAvailable(): Boolean {
        return true
    }

    companion object {
        val INITIAL_RECENT_WALLPAPERS =
            listOf(
                WallpaperModel(
                    wallpaperId = "zero",
                    placeholderColor = 0,
                ),
                WallpaperModel(
                    wallpaperId = "one",
                    placeholderColor = 1,
                ),
                WallpaperModel(
                    wallpaperId = "two",
                    placeholderColor = 2,
                ),
            )
    }
}