/*
 * Copyright (C) 2019 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.server.net.integrationtests

import android.app.usage.NetworkStatsManager
import android.content.ComponentName
import android.content.Context
import android.content.Context.BIND_AUTO_CREATE
import android.content.Context.BIND_IMPORTANT
import android.content.Intent
import android.content.ServiceConnection
import android.net.ConnectivityManager
import android.net.IDnsResolver
import android.net.INetd
import android.net.LinkProperties
import android.net.NetworkCapabilities.NET_CAPABILITY_CAPTIVE_PORTAL
import android.net.NetworkCapabilities.NET_CAPABILITY_INTERNET
import android.net.NetworkCapabilities.NET_CAPABILITY_VALIDATED
import android.net.NetworkCapabilities.TRANSPORT_CELLULAR
import android.net.NetworkRequest
import android.net.TestNetworkStackClient
import android.net.Uri
import android.net.metrics.IpConnectivityLog
import android.os.ConditionVariable
import android.os.IBinder
import android.os.SystemConfigManager
import android.os.UserHandle
import android.testing.TestableContext
import android.util.Log
import androidx.test.ext.junit.runners.AndroidJUnit4
import androidx.test.platform.app.InstrumentationRegistry
import com.android.server.ConnectivityService
import com.android.server.NetworkAgentWrapper
import com.android.server.TestNetIdManager
import com.android.server.connectivity.MockableSystemProperties
import com.android.server.connectivity.ProxyTracker
import com.android.testutils.TestableNetworkCallback
import org.junit.After
import org.junit.Before
import org.junit.BeforeClass
import org.junit.Test
import org.junit.runner.RunWith
import org.mockito.AdditionalAnswers
import org.mockito.ArgumentMatchers.anyString
import org.mockito.Mock
import org.mockito.Mockito.any
import org.mockito.Mockito.anyInt
import org.mockito.Mockito.doNothing
import org.mockito.Mockito.doReturn
import org.mockito.Mockito.eq
import org.mockito.Mockito.mock
import org.mockito.Mockito.spy
import org.mockito.MockitoAnnotations
import org.mockito.Spy
import kotlin.test.assertEquals
import kotlin.test.assertFalse
import kotlin.test.assertNotNull
import kotlin.test.assertTrue
import kotlin.test.fail

const val SERVICE_BIND_TIMEOUT_MS = 5_000L
const val TEST_TIMEOUT_MS = 10_000L

/**
 * Test that exercises an instrumented version of ConnectivityService against an instrumented
 * NetworkStack in a different test process.
 */
@RunWith(AndroidJUnit4::class)
class ConnectivityServiceIntegrationTest {
    // lateinit used here for mocks as they need to be reinitialized between each test and the test
    // should crash if they are used before being initialized.
    @Mock
    private lateinit var statsManager: NetworkStatsManager
    @Mock
    private lateinit var log: IpConnectivityLog
    @Mock
    private lateinit var netd: INetd
    @Mock
    private lateinit var dnsResolver: IDnsResolver
    @Mock
    private lateinit var systemConfigManager: SystemConfigManager
    @Spy
    private var context = TestableContext(realContext)

    // lateinit for these three classes under test, as they should be reset to a different instance
    // for every test but should always be initialized before use (or the test should crash).
    private lateinit var networkStackClient: TestNetworkStackClient
    private lateinit var service: ConnectivityService
    private lateinit var cm: ConnectivityManager

    companion object {
        // lateinit for this binder token, as it must be initialized before any test code is run
        // and use of it before init should crash the test.
        private lateinit var nsInstrumentation: INetworkStackInstrumentation
        private val bindingCondition = ConditionVariable(false)

        private val realContext get() = InstrumentationRegistry.getInstrumentation().context
        private val httpProbeUrl get() =
            realContext.getResources().getString(R.string.config_captive_portal_http_url)
        private val httpsProbeUrl get() =
            realContext.getResources().getString(R.string.config_captive_portal_https_url)

        private class InstrumentationServiceConnection : ServiceConnection {
            override fun onServiceConnected(name: ComponentName?, service: IBinder?) {
                Log.i("TestNetworkStack", "Service connected")
                try {
                    if (service == null) fail("Error binding to NetworkStack instrumentation")
                    if (::nsInstrumentation.isInitialized) fail("Service already connected")
                    nsInstrumentation = INetworkStackInstrumentation.Stub.asInterface(service)
                } finally {
                    bindingCondition.open()
                }
            }

            override fun onServiceDisconnected(name: ComponentName?) = Unit
        }

        @BeforeClass
        @JvmStatic
        fun setUpClass() {
            val intent = Intent(realContext, NetworkStackInstrumentationService::class.java)
            intent.action = INetworkStackInstrumentation::class.qualifiedName
            assertTrue(realContext.bindService(intent, InstrumentationServiceConnection(),
                    BIND_AUTO_CREATE or BIND_IMPORTANT),
                    "Error binding to instrumentation service")
            assertTrue(bindingCondition.block(SERVICE_BIND_TIMEOUT_MS),
                    "Timed out binding to instrumentation service " +
                            "after $SERVICE_BIND_TIMEOUT_MS ms")
        }
    }

    @Before
    fun setUp() {
        MockitoAnnotations.initMocks(this)
        val asUserCtx = mock(Context::class.java, AdditionalAnswers.delegatesTo<Context>(context))
        doReturn(UserHandle.ALL).`when`(asUserCtx).user
        doReturn(asUserCtx).`when`(context).createContextAsUser(eq(UserHandle.ALL), anyInt())
        doNothing().`when`(context).sendStickyBroadcast(any(), any())
        doReturn(Context.SYSTEM_CONFIG_SERVICE).`when`(context)
                .getSystemServiceName(SystemConfigManager::class.java)
        doReturn(systemConfigManager).`when`(context)
                .getSystemService(Context.SYSTEM_CONFIG_SERVICE)
        doReturn(IntArray(0)).`when`(systemConfigManager).getSystemPermissionUids(anyString())

        networkStackClient = TestNetworkStackClient(realContext)
        networkStackClient.init()
        networkStackClient.start()

        service = TestConnectivityService(makeDependencies())
        cm = ConnectivityManager(context, service)
        context.addMockSystemService(Context.CONNECTIVITY_SERVICE, cm)
        context.addMockSystemService(Context.NETWORK_STATS_SERVICE, statsManager)

        service.systemReadyInternal()
    }

    private inner class TestConnectivityService(deps: Dependencies) : ConnectivityService(
            context, dnsResolver, log, netd, deps)

    private fun makeDependencies(): ConnectivityService.Dependencies {
        val deps = spy(ConnectivityService.Dependencies())
        doReturn(networkStackClient).`when`(deps).networkStack
        doReturn(mock(ProxyTracker::class.java)).`when`(deps).makeProxyTracker(any(), any())
        doReturn(mock(MockableSystemProperties::class.java)).`when`(deps).systemProperties
        doReturn(TestNetIdManager()).`when`(deps).makeNetIdManager()
        return deps
    }

    @After
    fun tearDown() {
        nsInstrumentation.clearAllState()
    }

    @Test
    fun testValidation() {
        val request = NetworkRequest.Builder()
                .clearCapabilities()
                .addCapability(NET_CAPABILITY_INTERNET)
                .build()
        val testCallback = TestableNetworkCallback()

        cm.registerNetworkCallback(request, testCallback)
        nsInstrumentation.addHttpResponse(HttpResponse(httpProbeUrl, responseCode = 204))
        nsInstrumentation.addHttpResponse(HttpResponse(httpsProbeUrl, responseCode = 204))

        val na = NetworkAgentWrapper(TRANSPORT_CELLULAR, LinkProperties(), null /* ncTemplate */,
                context)
        networkStackClient.verifyNetworkMonitorCreated(na.network, TEST_TIMEOUT_MS)

        na.addCapability(NET_CAPABILITY_INTERNET)
        na.connect()

        testCallback.expectAvailableThenValidatedCallbacks(na.network, TEST_TIMEOUT_MS)
        assertEquals(2, nsInstrumentation.getRequestUrls().size)
    }

    @Test
    fun testCapportApi() {
        val request = NetworkRequest.Builder()
                .clearCapabilities()
                .addCapability(NET_CAPABILITY_INTERNET)
                .build()
        val testCb = TestableNetworkCallback()
        val apiUrl = "https://capport.android.com"

        cm.registerNetworkCallback(request, testCb)
        nsInstrumentation.addHttpResponse(HttpResponse(
                apiUrl,
                """
                    |{
                    |  "captive": true,
                    |  "user-portal-url": "https://login.capport.android.com",
                    |  "venue-info-url": "https://venueinfo.capport.android.com"
                    |}
                """.trimMargin()))

        // Tests will fail if a non-mocked query is received: mock the HTTPS probe, but not the
        // HTTP probe as it should not be sent.
        // Even if the HTTPS probe succeeds, a portal should be detected as the API takes precedence
        // in that case.
        nsInstrumentation.addHttpResponse(HttpResponse(httpsProbeUrl, responseCode = 204))

        val lp = LinkProperties()
        lp.captivePortalApiUrl = Uri.parse(apiUrl)
        val na = NetworkAgentWrapper(TRANSPORT_CELLULAR, lp, null /* ncTemplate */, context)
        networkStackClient.verifyNetworkMonitorCreated(na.network, TEST_TIMEOUT_MS)

        na.addCapability(NET_CAPABILITY_INTERNET)
        na.connect()

        testCb.expectAvailableCallbacks(na.network, validated = false, tmt = TEST_TIMEOUT_MS)

        val capportData = testCb.expectLinkPropertiesThat(na, TEST_TIMEOUT_MS) {
            it.captivePortalData != null
        }.lp.captivePortalData
        assertNotNull(capportData)
        assertTrue(capportData.isCaptive)
        assertEquals(Uri.parse("https://login.capport.android.com"), capportData.userPortalUrl)
        assertEquals(Uri.parse("https://venueinfo.capport.android.com"), capportData.venueInfoUrl)

        val nc = testCb.expectCapabilitiesWith(NET_CAPABILITY_CAPTIVE_PORTAL, na, TEST_TIMEOUT_MS)
        assertFalse(nc.hasCapability(NET_CAPABILITY_VALIDATED))
    }
}