/*
 * 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.systemui.lifecycle

import androidx.compose.foundation.layout.Column
import androidx.compose.material3.Text
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.ui.Modifier
import androidx.compose.ui.platform.testTag
import androidx.compose.ui.test.assertTextEquals
import androidx.compose.ui.test.hasTestTag
import androidx.compose.ui.test.junit4.createComposeRule
import androidx.test.ext.junit.runners.AndroidJUnit4
import androidx.test.filters.SmallTest
import com.android.systemui.SysuiTestCase
import com.android.systemui.ui.viewmodel.FakeSysUiViewModel
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.flow.map
import org.junit.Rule
import org.junit.Test
import org.junit.runner.RunWith

@SmallTest
@RunWith(AndroidJUnit4::class)
class HydratorTest : SysuiTestCase() {

    @get:Rule val composeRule = createComposeRule()

    @Test
    fun hydratedStateOf() {
        val keepAliveMutable = mutableStateOf(true)
        val upstreamStateFlow = MutableStateFlow(true)
        val upstreamFlow = upstreamStateFlow.map { !it }
        composeRule.setContent {
            val keepAlive by keepAliveMutable
            if (keepAlive) {
                val viewModel =
                    rememberViewModel("test") {
                        FakeSysUiViewModel(
                            upstreamFlow = upstreamFlow,
                            upstreamStateFlow = upstreamStateFlow,
                        )
                    }

                Column {
                    Text(
                        "upstreamStateFlow=${viewModel.stateBackedByStateFlow}",
                        Modifier.testTag("upstreamStateFlow"),
                    )
                    Text(
                        "upstreamFlow=${viewModel.stateBackedByFlow}",
                        Modifier.testTag("upstreamFlow"),
                    )
                }
            }
        }

        composeRule.waitForIdle()
        composeRule
            .onNode(hasTestTag("upstreamStateFlow"))
            .assertTextEquals("upstreamStateFlow=true")
        composeRule.onNode(hasTestTag("upstreamFlow")).assertTextEquals("upstreamFlow=false")

        composeRule.runOnUiThread { upstreamStateFlow.value = false }
        composeRule.waitForIdle()
        composeRule
            .onNode(hasTestTag("upstreamStateFlow"))
            .assertTextEquals("upstreamStateFlow=false")
        composeRule.onNode(hasTestTag("upstreamFlow")).assertTextEquals("upstreamFlow=true")
    }
}