/*
 * Copyright (C) 2025 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.keyguard.ui.viewmodel

import com.android.systemui.dagger.SysUISingleton
import com.android.systemui.keyguard.domain.interactor.FromDozingTransitionInteractor.Companion.TO_DREAMING_DURATION
import com.android.systemui.keyguard.shared.model.Edge
import com.android.systemui.keyguard.shared.model.KeyguardState.DOZING
import com.android.systemui.keyguard.shared.model.KeyguardState.DREAMING
import com.android.systemui.keyguard.ui.KeyguardTransitionAnimationFlow
import com.android.systemui.keyguard.ui.transitions.DeviceEntryIconTransition
import com.android.systemui.scene.shared.model.Scenes
import javax.inject.Inject
import kotlinx.coroutines.flow.Flow

/**
 * Breaks down DOZING->DREAMING transition into discrete steps for corresponding views to consume.
 */
@SysUISingleton
class DozingToDreamingTransitionViewModel
@Inject
constructor(animationFlow: KeyguardTransitionAnimationFlow) : DeviceEntryIconTransition {
    private val transitionAnimation =
        animationFlow
            .setup(
                duration = TO_DREAMING_DURATION,
                edge = Edge.create(from = DOZING, to = Scenes.Dream),
            )
            .setupWithoutSceneContainer(edge = Edge.create(from = DOZING, to = DREAMING))

    val lockscreenAlpha: Flow<Float> = transitionAnimation.immediatelyTransitionTo(0f)

    val nonAuthUIAlpha: Flow<Float> =
        transitionAnimation.sharedFlow(
            duration = TO_DREAMING_DURATION,
            onStep = { null },
            onCancel = { 1f },
            onFinish = { 1f },
        )

    override val deviceEntryParentViewAlpha: Flow<Float> =
        transitionAnimation.immediatelyTransitionTo(0f)
}