/*
 * 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.launcher3

import com.android.launcher3.DeviceProfile.DEFAULT_DEVICE_PROFILE
import com.android.launcher3.util.MutableListenableRef

/** Expose Launcher Ui State to Taskbar. */
class LauncherUiState {

    private val _launcherStateRef = MutableListenableRef(LauncherState.NORMAL)
    private val _deviceProfileRef = MutableListenableRef(DEFAULT_DEVICE_PROFILE)
    private val _activityFlagsRef = MutableListenableRef(0)
    private val _isSplitSelectActiveRef = MutableListenableRef(false)
    private val _isOverlayShown = MutableListenableRef(false)
    private val _taskbarAlignmentChannelAlphaRef = MutableListenableRef(0f)
    private val _isTopResumedActivityRef = MutableListenableRef(false)

    val deviceProfileRef = _deviceProfileRef.asListenable()
    val isSplitSelectActiveRef = _isSplitSelectActiveRef.asListenable()
    val launcherStateRef = _launcherStateRef.asListenable()
    val taskbarAlignmentChannelAlpha = _taskbarAlignmentChannelAlphaRef.asListenable()
    val isTopResumedActivityRef = _isTopResumedActivityRef.asListenable()

    val isResumed: Boolean
        get() = (_activityFlagsRef.value and BaseActivity.ACTIVITY_STATE_RESUMED) != 0

    val isDeviceProfileInitialized: Boolean
        get() = _deviceProfileRef.value !== DEFAULT_DEVICE_PROFILE

    val isOverlayShownRef = _isOverlayShown.asListenable()

    // Split select state
    private var _initialTask = SplitSelectTask()
    private var _secondTask = SplitSelectTask()

    fun setLauncherState(launcherState: LauncherState) {
        _launcherStateRef.diffAndDispatch(launcherState)
    }

    fun setDeviceProfile(deviceProfile: DeviceProfile) {
        _deviceProfileRef.diffAndDispatch(deviceProfile)
    }

    fun setActivityFlag(flags: Int) {
        _activityFlagsRef.diffAndDispatch(flags)
    }

    fun setSplitSelectInitialTask(initialTask: SplitSelectTask) {
        _initialTask = initialTask
        updateIsSplitSelectActiveRef()
    }

    fun setSplitSelectSecondTask(secondTask: SplitSelectTask) {
        _secondTask = secondTask
        updateIsSplitSelectActiveRef()
    }

    fun setIsOverlayShown(isOverlayShown: Boolean) {
        _isOverlayShown.diffAndDispatch(isOverlayShown)
    }

    fun setTaskbarAlignmentChannelAlpha(alpha: Float) {
        _taskbarAlignmentChannelAlphaRef.diffAndDispatch(alpha)
    }

    fun setIsTopResumedActivity(isTopResumedActivity: Boolean) {
        _isTopResumedActivityRef.diffAndDispatch(isTopResumedActivity)
    }

    private fun updateIsSplitSelectActiveRef() {
        _isSplitSelectActiveRef.diffAndDispatch(
            _initialTask.isIntentSet && !_secondTask.isIntentSet
        )
    }

    private fun <T> MutableListenableRef<T>.diffAndDispatch(newValue: T) {
        if (value != newValue) {
            dispatchValue(newValue)
        }
    }
}