/*
 * Copyright (C) 2017 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 android.net.nsd;

import static libcore.junit.util.compat.CoreCompatChangeRule.DisableCompatChanges;
import static libcore.junit.util.compat.CoreCompatChangeRule.EnableCompatChanges;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.fail;
import static org.mockito.Mockito.any;
import static org.mockito.Mockito.doReturn;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.never;
import static org.mockito.Mockito.reset;
import static org.mockito.Mockito.timeout;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;

import android.compat.testing.PlatformCompatChangeRule;
import android.content.Context;
import android.os.Build;

import androidx.test.filters.SmallTest;

import com.android.testutils.DevSdkIgnoreRule;
import com.android.testutils.DevSdkIgnoreRunner;
import com.android.testutils.ExceptionUtils;

import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.TestRule;
import org.junit.runner.RunWith;
import org.mockito.ArgumentCaptor;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;

@RunWith(DevSdkIgnoreRunner.class)
@SmallTest
@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
public class NsdManagerTest {

    static final int PROTOCOL = NsdManager.PROTOCOL_DNS_SD;

    @Rule
    public TestRule compatChangeRule = new PlatformCompatChangeRule();

    @Mock Context mContext;
    @Mock INsdManager mService;
    @Mock INsdServiceConnector mServiceConn;

    NsdManager mManager;
    INsdManagerCallback mCallback;

    long mTimeoutMs = 200; // non-final so that tests can adjust the value.

    @Before
    public void setUp() throws Exception {
        MockitoAnnotations.initMocks(this);

        doReturn(mServiceConn).when(mService).connect(any());
        mManager = new NsdManager(mContext, mService);
        final ArgumentCaptor<INsdManagerCallback> cbCaptor = ArgumentCaptor.forClass(
                INsdManagerCallback.class);
        verify(mService).connect(cbCaptor.capture());
        mCallback = cbCaptor.getValue();
    }

    @Test
    @EnableCompatChanges(NsdManager.RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS)
    public void testResolveServiceS() throws Exception {
        verify(mServiceConn, never()).startDaemon();
        doTestResolveService();
    }

    @Test
    @DisableCompatChanges(NsdManager.RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS)
    public void testResolveServicePreS() throws Exception {
        verify(mServiceConn).startDaemon();
        doTestResolveService();
    }

    @Test
    @EnableCompatChanges(NsdManager.RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS)
    public void testDiscoverServiceS() throws Exception {
        verify(mServiceConn, never()).startDaemon();
        doTestDiscoverService();
    }

    @Test
    @DisableCompatChanges(NsdManager.RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS)
    public void testDiscoverServicePreS() throws Exception {
        verify(mServiceConn).startDaemon();
        doTestDiscoverService();
    }

    @Test
    @EnableCompatChanges(NsdManager.RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS)
    public void testParallelResolveServiceS() throws Exception {
        verify(mServiceConn, never()).startDaemon();
        doTestParallelResolveService();
    }

    @Test
    @DisableCompatChanges(NsdManager.RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS)
    public void testParallelResolveServicePreS() throws Exception {
        verify(mServiceConn).startDaemon();
        doTestParallelResolveService();
    }

    @Test
    @EnableCompatChanges(NsdManager.RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS)
    public void testInvalidCallsS() throws Exception {
        verify(mServiceConn, never()).startDaemon();
        doTestInvalidCalls();
    }

    @Test
    @DisableCompatChanges(NsdManager.RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS)
    public void testInvalidCallsPreS() throws Exception {
        verify(mServiceConn).startDaemon();
        doTestInvalidCalls();
    }

    @Test
    @EnableCompatChanges(NsdManager.RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS)
    public void testRegisterServiceS() throws Exception {
        verify(mServiceConn, never()).startDaemon();
        doTestRegisterService();
    }

    @Test
    @DisableCompatChanges(NsdManager.RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS)
    public void testRegisterServicePreS() throws Exception {
        verify(mServiceConn).startDaemon();
        doTestRegisterService();
    }

    private void doTestResolveService() throws Exception {
        NsdManager manager = mManager;

        NsdServiceInfo request = new NsdServiceInfo("a_name", "a_type");
        NsdServiceInfo reply = new NsdServiceInfo("resolved_name", "resolved_type");
        NsdManager.ResolveListener listener = mock(NsdManager.ResolveListener.class);

        manager.resolveService(request, listener);
        int key1 = getRequestKey(req -> verify(mServiceConn).resolveService(req.capture(), any()));
        int err = 33;
        mCallback.onResolveServiceFailed(key1, err);
        verify(listener, timeout(mTimeoutMs).times(1)).onResolveFailed(request, err);

        manager.resolveService(request, listener);
        int key2 = getRequestKey(req ->
                verify(mServiceConn, times(2)).resolveService(req.capture(), any()));
        mCallback.onResolveServiceSucceeded(key2, reply);
        verify(listener, timeout(mTimeoutMs).times(1)).onServiceResolved(reply);
    }

    private void doTestParallelResolveService() throws Exception {
        NsdManager manager = mManager;

        NsdServiceInfo request = new NsdServiceInfo("a_name", "a_type");
        NsdServiceInfo reply = new NsdServiceInfo("resolved_name", "resolved_type");

        NsdManager.ResolveListener listener1 = mock(NsdManager.ResolveListener.class);
        NsdManager.ResolveListener listener2 = mock(NsdManager.ResolveListener.class);

        manager.resolveService(request, listener1);
        int key1 = getRequestKey(req -> verify(mServiceConn).resolveService(req.capture(), any()));

        manager.resolveService(request, listener2);
        int key2 = getRequestKey(req ->
                verify(mServiceConn, times(2)).resolveService(req.capture(), any()));

        mCallback.onResolveServiceSucceeded(key2, reply);
        mCallback.onResolveServiceSucceeded(key1, reply);

        verify(listener1, timeout(mTimeoutMs).times(1)).onServiceResolved(reply);
        verify(listener2, timeout(mTimeoutMs).times(1)).onServiceResolved(reply);
    }

    private void doTestRegisterService() throws Exception {
        NsdManager manager = mManager;

        NsdServiceInfo request1 = new NsdServiceInfo("a_name", "a_type");
        NsdServiceInfo request2 = new NsdServiceInfo("another_name", "another_type");
        request1.setPort(2201);
        request2.setPort(2202);
        NsdManager.RegistrationListener listener1 = mock(NsdManager.RegistrationListener.class);
        NsdManager.RegistrationListener listener2 = mock(NsdManager.RegistrationListener.class);

        // Register two services
        manager.registerService(request1, PROTOCOL, listener1);
        int key1 = getRequestKey(req -> verify(mServiceConn).registerService(req.capture(), any()));

        manager.registerService(request2, PROTOCOL, listener2);
        int key2 = getRequestKey(req ->
                verify(mServiceConn, times(2)).registerService(req.capture(), any()));

        // First reques fails, second request succeeds
        mCallback.onRegisterServiceSucceeded(key2, request2);
        verify(listener2, timeout(mTimeoutMs).times(1)).onServiceRegistered(request2);

        int err = 1;
        mCallback.onRegisterServiceFailed(key1, err);
        verify(listener1, timeout(mTimeoutMs).times(1)).onRegistrationFailed(request1, err);

        // Client retries first request, it succeeds
        manager.registerService(request1, PROTOCOL, listener1);
        int key3 = getRequestKey(req ->
                verify(mServiceConn, times(3)).registerService(req.capture(), any()));

        mCallback.onRegisterServiceSucceeded(key3, request1);
        verify(listener1, timeout(mTimeoutMs).times(1)).onServiceRegistered(request1);

        // First request is unregistered, it succeeds
        manager.unregisterService(listener1);
        int key3again = getRequestKey(req -> verify(mServiceConn).unregisterService(req.capture()));
        assertEquals(key3, key3again);

        mCallback.onUnregisterServiceSucceeded(key3again);
        verify(listener1, timeout(mTimeoutMs).times(1)).onServiceUnregistered(request1);

        // Second request is unregistered, it fails
        manager.unregisterService(listener2);
        int key2again = getRequestKey(req ->
                verify(mServiceConn, times(2)).unregisterService(req.capture()));
        assertEquals(key2, key2again);

        mCallback.onUnregisterServiceFailed(key2again, err);
        verify(listener2, timeout(mTimeoutMs).times(1)).onUnregistrationFailed(request2, err);

        // TODO: do not unregister listener until service is unregistered
        // Client retries unregistration of second request, it succeeds
        //manager.unregisterService(listener2);
        //int key2yetAgain = verifyRequest(NsdManager.UNREGISTER_SERVICE);
        //assertEquals(key2, key2yetAgain);

        //sendResponse(NsdManager.UNREGISTER_SERVICE_SUCCEEDED, 0, key2yetAgain, null);
        //verify(listener2, timeout(mTimeoutMs).times(1)).onServiceUnregistered(request2);
    }

    private void doTestDiscoverService() throws Exception {
        NsdManager manager = mManager;

        NsdServiceInfo reply1 = new NsdServiceInfo("a_name", "a_type");
        NsdServiceInfo reply2 = new NsdServiceInfo("another_name", "a_type");
        NsdServiceInfo reply3 = new NsdServiceInfo("a_third_name", "a_type");

        NsdManager.DiscoveryListener listener = mock(NsdManager.DiscoveryListener.class);

        // Client registers for discovery, request fails
        manager.discoverServices("a_type", PROTOCOL, listener);
        int key1 = getRequestKey(req ->
                verify(mServiceConn).discoverServices(req.capture(), any()));

        int err = 1;
        mCallback.onDiscoverServicesFailed(key1, err);
        verify(listener, timeout(mTimeoutMs).times(1)).onStartDiscoveryFailed("a_type", err);

        // Client retries, request succeeds
        manager.discoverServices("a_type", PROTOCOL, listener);
        int key2 = getRequestKey(req ->
                verify(mServiceConn, times(2)).discoverServices(req.capture(), any()));

        mCallback.onDiscoverServicesStarted(key2, reply1);
        verify(listener, timeout(mTimeoutMs).times(1)).onDiscoveryStarted("a_type");


        // mdns notifies about services
        mCallback.onServiceFound(key2, reply1);
        verify(listener, timeout(mTimeoutMs).times(1)).onServiceFound(reply1);

        mCallback.onServiceFound(key2, reply2);
        verify(listener, timeout(mTimeoutMs).times(1)).onServiceFound(reply2);

        mCallback.onServiceLost(key2, reply2);
        verify(listener, timeout(mTimeoutMs).times(1)).onServiceLost(reply2);


        // Client unregisters its listener
        manager.stopServiceDiscovery(listener);
        int key2again = getRequestKey(req -> verify(mServiceConn).stopDiscovery(req.capture()));
        assertEquals(key2, key2again);

        // TODO: unregister listener immediately and stop notifying it about services
        // Notifications are still passed to the client's listener
        mCallback.onServiceLost(key2, reply1);
        verify(listener, timeout(mTimeoutMs).times(1)).onServiceLost(reply1);

        // Client is notified of complete unregistration
        mCallback.onStopDiscoverySucceeded(key2again);
        verify(listener, timeout(mTimeoutMs).times(1)).onDiscoveryStopped("a_type");

        // Notifications are not passed to the client anymore
        mCallback.onServiceFound(key2, reply3);
        verify(listener, timeout(mTimeoutMs).times(0)).onServiceLost(reply3);


        // Client registers for service discovery
        reset(listener);
        manager.discoverServices("a_type", PROTOCOL, listener);
        int key3 = getRequestKey(req ->
                verify(mServiceConn, times(3)).discoverServices(req.capture(), any()));

        mCallback.onDiscoverServicesStarted(key3, reply1);
        verify(listener, timeout(mTimeoutMs).times(1)).onDiscoveryStarted("a_type");

        // Client unregisters immediately, it fails
        manager.stopServiceDiscovery(listener);
        int key3again = getRequestKey(req ->
                verify(mServiceConn, times(2)).stopDiscovery(req.capture()));
        assertEquals(key3, key3again);

        err = 2;
        mCallback.onStopDiscoveryFailed(key3again, err);
        verify(listener, timeout(mTimeoutMs).times(1)).onStopDiscoveryFailed("a_type", err);

        // New notifications are not passed to the client anymore
        mCallback.onServiceFound(key3, reply1);
        verify(listener, timeout(mTimeoutMs).times(0)).onServiceFound(reply1);
    }

    public void doTestInvalidCalls() {
        NsdManager manager = mManager;

        NsdManager.RegistrationListener listener1 = mock(NsdManager.RegistrationListener.class);
        NsdManager.DiscoveryListener listener2 = mock(NsdManager.DiscoveryListener.class);
        NsdManager.ResolveListener listener3 = mock(NsdManager.ResolveListener.class);

        NsdServiceInfo invalidService = new NsdServiceInfo(null, null);
        NsdServiceInfo validService = new NsdServiceInfo("a_name", "a_type");
        validService.setPort(2222);

        // Service registration
        //  - invalid arguments
        mustFail(() -> { manager.unregisterService(null); });
        mustFail(() -> { manager.registerService(null, -1, null); });
        mustFail(() -> { manager.registerService(null, PROTOCOL, listener1); });
        mustFail(() -> { manager.registerService(invalidService, PROTOCOL, listener1); });
        mustFail(() -> { manager.registerService(validService, -1, listener1); });
        mustFail(() -> { manager.registerService(validService, PROTOCOL, null); });
        manager.registerService(validService, PROTOCOL, listener1);
        //  - listener already registered
        mustFail(() -> { manager.registerService(validService, PROTOCOL, listener1); });
        manager.unregisterService(listener1);
        // TODO: make listener immediately reusable
        //mustFail(() -> { manager.unregisterService(listener1); });
        //manager.registerService(validService, PROTOCOL, listener1);

        // Discover service
        //  - invalid arguments
        mustFail(() -> { manager.stopServiceDiscovery(null); });
        mustFail(() -> { manager.discoverServices(null, -1, null); });
        mustFail(() -> { manager.discoverServices(null, PROTOCOL, listener2); });
        mustFail(() -> { manager.discoverServices("a_service", -1, listener2); });
        mustFail(() -> { manager.discoverServices("a_service", PROTOCOL, null); });
        manager.discoverServices("a_service", PROTOCOL, listener2);
        //  - listener already registered
        mustFail(() -> { manager.discoverServices("another_service", PROTOCOL, listener2); });
        manager.stopServiceDiscovery(listener2);
        // TODO: make listener immediately reusable
        //mustFail(() -> { manager.stopServiceDiscovery(listener2); });
        //manager.discoverServices("another_service", PROTOCOL, listener2);

        // Resolver service
        //  - invalid arguments
        mustFail(() -> { manager.resolveService(null, null); });
        mustFail(() -> { manager.resolveService(null, listener3); });
        mustFail(() -> { manager.resolveService(invalidService, listener3); });
        mustFail(() -> { manager.resolveService(validService, null); });
        manager.resolveService(validService, listener3);
        //  - listener already registered:w
        mustFail(() -> { manager.resolveService(validService, listener3); });
    }

    public void mustFail(Runnable fn) {
        try {
            fn.run();
            fail();
        } catch (Exception expected) {
        }
    }

    int getRequestKey(ExceptionUtils.ThrowingConsumer<ArgumentCaptor<Integer>> verifier)
            throws Exception {
        final ArgumentCaptor<Integer> captor = ArgumentCaptor.forClass(Integer.class);
        verifier.accept(captor);
        return captor.getValue();
    }
}