/*
 * Copyright (C) 2024 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.quickstep.task.thumbnail

import android.annotation.ColorInt
import android.graphics.Rect
import androidx.core.graphics.ColorUtils
import com.android.quickstep.recents.data.RecentTasksRepository
import com.android.quickstep.recents.viewmodel.RecentsViewData
import com.android.quickstep.task.thumbnail.TaskThumbnailUiState.BackgroundOnly
import com.android.quickstep.task.thumbnail.TaskThumbnailUiState.LiveTile
import com.android.quickstep.task.thumbnail.TaskThumbnailUiState.Snapshot
import com.android.quickstep.task.thumbnail.TaskThumbnailUiState.Uninitialized
import com.android.quickstep.task.viewmodel.TaskViewData
import com.android.systemui.shared.recents.model.Task
import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.flow.combine
import kotlinx.coroutines.flow.distinctUntilChanged
import kotlinx.coroutines.flow.flatMapLatest
import kotlinx.coroutines.flow.flowOf
import kotlinx.coroutines.flow.map

@OptIn(ExperimentalCoroutinesApi::class)
class TaskThumbnailViewModel(
    recentsViewData: RecentsViewData,
    taskViewData: TaskViewData,
    private val tasksRepository: RecentTasksRepository,
) {
    private val task = MutableStateFlow<Flow<Task?>>(flowOf(null))
    private var boundTaskIsRunning = false

    val recentsFullscreenProgress = recentsViewData.fullscreenProgress
    val inheritedScale =
        combine(recentsViewData.scale, taskViewData.scale) { recentsScale, taskScale ->
            recentsScale * taskScale
        }
    val uiState: Flow<TaskThumbnailUiState> =
        task
            .flatMapLatest { taskFlow ->
                taskFlow.map { taskVal ->
                    when {
                        taskVal == null -> Uninitialized
                        boundTaskIsRunning -> LiveTile
                        isBackgroundOnly(taskVal) ->
                            BackgroundOnly(taskVal.colorBackground.removeAlpha())
                        isSnapshotState(taskVal) -> {
                            val bitmap = taskVal.thumbnail?.thumbnail!!
                            Snapshot(
                                bitmap,
                                Rect(0, 0, bitmap.width, bitmap.height),
                                taskVal.colorBackground.removeAlpha()
                            )
                        }
                        else -> Uninitialized
                    }
                }
            }
            .distinctUntilChanged()

    fun bind(taskThumbnail: TaskThumbnail) {
        boundTaskIsRunning = taskThumbnail.isRunning
        task.value = tasksRepository.getTaskDataById(taskThumbnail.taskId)
    }

    private fun isBackgroundOnly(task: Task): Boolean = task.isLocked || task.thumbnail == null

    private fun isSnapshotState(task: Task): Boolean {
        val thumbnailPresent = task.thumbnail?.thumbnail != null
        val taskLocked = task.isLocked

        return thumbnailPresent && !taskLocked
    }

    @ColorInt private fun Int.removeAlpha(): Int = ColorUtils.setAlphaComponent(this, 0xff)
}