/*
 * Copyright (C) 2016 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.app.tracing.benchmark

import android.os.Trace
import android.perftests.utils.BenchmarkState
import android.perftests.utils.PerfStatusReporter
import android.platform.test.annotations.EnableFlags
import android.platform.test.flag.junit.SetFlagsRule
import android.platform.test.rule.EnsureDeviceSettingsRule
import androidx.test.ext.junit.runners.AndroidJUnit4
import androidx.test.filters.SmallTest
import com.android.app.tracing.coroutines.createCoroutineTracingContext
import com.android.app.tracing.coroutines.nameCoroutine
import com.android.app.tracing.coroutines.traceCoroutine
import com.android.systemui.Flags
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch
import kotlinx.coroutines.runBlocking
import kotlinx.coroutines.withContext
import kotlinx.coroutines.yield
import org.junit.After
import org.junit.Assert
import org.junit.Before
import org.junit.ClassRule
import org.junit.Rule
import org.junit.Test
import org.junit.runner.RunWith

private val TAG: String = TraceContextMicroBenchmark::class.java.simpleName

@RunWith(AndroidJUnit4::class)
@EnableFlags(Flags.FLAG_COROUTINE_TRACING)
class TraceContextMicroBenchmark {

    @get:Rule val perfStatusReporter = PerfStatusReporter()

    @get:Rule val setFlagsRule = SetFlagsRule()

    companion object {
        @JvmField @ClassRule(order = 1) var ensureDeviceSettingsRule = EnsureDeviceSettingsRule()
    }

    @Before
    fun before() {
        Assert.assertTrue(Trace.isEnabled())
    }

    @After
    fun after() {
        Assert.assertTrue(Trace.isEnabled())
    }

    private suspend fun ensureSuspend(state: BenchmarkState) {
        state.pauseTiming()
        delay(1)
        state.resumeTiming()
    }

    @SmallTest
    @Test
    fun testSingleTraceSection() {
        val state = perfStatusReporter.benchmarkState
        runBlocking(createCoroutineTracingContext("root")) {
            while (state.keepRunning()) {
                traceCoroutine("hello-world") { ensureSuspend(state) }
            }
        }
    }

    @SmallTest
    @Test
    fun testNestedContext() {
        val state = perfStatusReporter.benchmarkState

        val context1 = createCoroutineTracingContext("scope1")
        val context2 = nameCoroutine("scope2")
        runBlocking {
            while (state.keepRunning()) {
                withContext(context1) {
                    traceCoroutine("hello") {
                        traceCoroutine("world") {
                            withContext(context2) {
                                traceCoroutine("hallo") {
                                    traceCoroutine("welt") { ensureSuspend(state) }
                                    ensureSuspend(state)
                                }
                            }
                            ensureSuspend(state)
                        }
                        ensureSuspend(state)
                    }
                }
            }
        }
    }

    @SmallTest
    @Test
    fun testInterleavedLaunch() {
        val state = perfStatusReporter.benchmarkState

        runBlocking(createCoroutineTracingContext("root")) {
            val job1 =
                launch(nameCoroutine("scope1")) {
                    while (true) {
                        traceCoroutine("hello") {
                            traceCoroutine("world") { yield() }
                            yield()
                        }
                    }
                }
            val job2 =
                launch(nameCoroutine("scope2")) {
                    while (true) {
                        traceCoroutine("hallo") {
                            traceCoroutine("welt") { yield() }
                            yield()
                        }
                    }
                }
            while (state.keepRunning()) {
                repeat(10_000) { traceCoroutine("main-loop") { yield() } }
            }
            job1.cancel()
            job2.cancel()
        }
    }
}