/*
 * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */

package org.opendaylight.netconf.client;

import static junit.framework.Assert.assertEquals;
import static junit.framework.Assert.assertTrue;
import static org.junit.Assert.assertNotEquals;
import static org.mockito.Matchers.any;
import static org.mockito.Matchers.anyObject;
import static org.mockito.Matchers.anyString;
import static org.mockito.Mockito.doAnswer;
import static org.mockito.Mockito.doReturn;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;

import com.google.common.base.Optional;
import com.google.common.collect.ImmutableSet;
import io.netty.channel.Channel;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.ChannelProgressivePromise;
import io.netty.channel.ChannelPromise;
import io.netty.channel.EventLoop;
import io.netty.handler.ssl.SslHandler;
import io.netty.util.HashedWheelTimer;
import io.netty.util.Timer;
import io.netty.util.concurrent.GenericFutureListener;
import io.netty.util.concurrent.Promise;
import java.io.InputStream;
import java.util.Set;
import org.junit.Before;
import org.junit.Test;
import org.mockito.internal.util.collections.Sets;
import org.opendaylight.controller.config.util.xml.XmlUtil;
import org.opendaylight.netconf.api.NetconfClientSessionPreferences;
import org.opendaylight.netconf.api.NetconfDocumentedException;
import org.opendaylight.netconf.api.NetconfMessage;
import org.opendaylight.netconf.api.messages.NetconfHelloMessage;
import org.opendaylight.netconf.nettyutil.handler.ChunkedFramingMechanismEncoder;
import org.opendaylight.netconf.nettyutil.handler.NetconfXMLToHelloMessageDecoder;
import org.opendaylight.netconf.nettyutil.handler.NetconfXMLToMessageDecoder;
import org.opendaylight.netconf.nettyutil.handler.exi.EXIParameters;
import org.opendaylight.netconf.nettyutil.handler.exi.NetconfStartExiMessage;
import org.opendaylight.netconf.util.messages.NetconfMessageUtil;
import org.opendaylight.netconf.util.test.XmlFileLoader;
import org.w3c.dom.Document;

public class NetconfClientSessionNegotiatorTest {

    private NetconfHelloMessage helloMessage;
    private ChannelPipeline pipeline;
    private ChannelPromise future;
    private Channel channel;
    private ChannelInboundHandlerAdapter channelInboundHandlerAdapter;

    @Before
    public void setUp() throws Exception {
        helloMessage = NetconfHelloMessage.createClientHello(Sets.newSet("exi:1.0"), Optional.absent());
        pipeline = mockChannelPipeline();
        future = mockChannelFuture();
        channel = mockChannel();
        mockEventLoop();
    }

    private static ChannelHandler mockChannelHandler() {
        ChannelHandler handler = mock(ChannelHandler.class);
        return handler;
    }

    private Channel mockChannel() {
        Channel ret = mock(Channel.class);
        ChannelHandler channelHandler = mockChannelHandler();
        doReturn("").when(ret).toString();
        doReturn(future).when(ret).newPromise();
        doReturn(future).when(ret).close();
        doReturn(future).when(ret).writeAndFlush(anyObject());
        doReturn(future).when(ret).writeAndFlush(anyObject(), anyObject());
        doReturn(true).when(ret).isOpen();
        doReturn(pipeline).when(ret).pipeline();
        doReturn("").when(pipeline).toString();
        doReturn(pipeline).when(pipeline).remove(any(ChannelHandler.class));
        doReturn(channelHandler).when(pipeline).remove(anyString());
        return ret;
    }

    private static ChannelPromise mockChannelFuture() {
        ChannelPromise future = mock(ChannelPromise.class);
        doReturn(future).when(future).addListener(any(GenericFutureListener.class));
        return future;
    }

    private static ChannelPipeline mockChannelPipeline() {
        ChannelPipeline pipeline = mock(ChannelPipeline.class);
        ChannelHandler handler = mock(ChannelHandler.class);
        doReturn(pipeline).when(pipeline).addAfter(anyString(), anyString(), any(ChannelHandler.class));
        doReturn(null).when(pipeline).get(SslHandler.class);
        doReturn(pipeline).when(pipeline).addLast(anyString(), any(ChannelHandler.class));
        doReturn(handler).when(pipeline).replace(anyString(), anyString(), any(ChunkedFramingMechanismEncoder.class));

        NetconfXMLToHelloMessageDecoder messageDecoder = new NetconfXMLToHelloMessageDecoder();
        doReturn(messageDecoder).when(pipeline).replace(anyString(), anyString(), any(NetconfXMLToMessageDecoder
                .class));
        doReturn(pipeline).when(pipeline).replace(any(ChannelHandler.class), anyString(), any(NetconfClientSession
                .class));
        return pipeline;
    }

    private void mockEventLoop() {
        final EventLoop eventLoop = mock(EventLoop.class);
        doReturn(eventLoop).when(channel).eventLoop();
        doAnswer(invocation -> {
            invocation.getArgumentAt(0, Runnable.class).run();
            return null;
        }).when(eventLoop).execute(any(Runnable.class));
    }

    private NetconfClientSessionNegotiator createNetconfClientSessionNegotiator(
            final Promise<NetconfClientSession> promise,
            final NetconfMessage startExi) {
        ChannelProgressivePromise progressivePromise = mock(ChannelProgressivePromise.class);
        NetconfClientSessionPreferences preferences = new NetconfClientSessionPreferences(helloMessage, startExi);
        doReturn(progressivePromise).when(promise).setFailure(any(Throwable.class));

        long timeout = 10L;
        NetconfClientSessionListener sessionListener = mock(NetconfClientSessionListener.class);
        Timer timer = new HashedWheelTimer();
        return new NetconfClientSessionNegotiator(preferences, promise, channel, timer, sessionListener, timeout);
    }

    private static NetconfHelloMessage createHelloMsg(final String name) throws Exception {
        final InputStream stream = NetconfClientSessionNegotiatorTest.class.getResourceAsStream(name);
        final Document doc = XmlUtil.readXmlToDocument(stream);

        return new NetconfHelloMessage(doc);
    }

    private static Set<String> createCapabilities(final String name) throws Exception {
        NetconfHelloMessage hello = createHelloMsg(name);

        return ImmutableSet.copyOf(NetconfMessageUtil.extractCapabilitiesFromHello(hello.getDocument()));
    }

    @Test
    public void testNetconfClientSessionNegotiator() throws NetconfDocumentedException {
        Promise<NetconfClientSession> promise = mock(Promise.class);
        doReturn(promise).when(promise).setSuccess(anyObject());
        NetconfClientSessionNegotiator negotiator = createNetconfClientSessionNegotiator(promise, null);

        negotiator.channelActive(null);
        Set<String> caps = Sets.newSet("a", "b");
        NetconfHelloMessage helloServerMessage = NetconfHelloMessage.createServerHello(caps, 10);
        negotiator.handleMessage(helloServerMessage);
        verify(promise).setSuccess(anyObject());
    }

    @Test
    public void testNetconfClientSessionNegotiatorWithEXI() throws Exception {
        Promise<NetconfClientSession> promise = mock(Promise.class);
        NetconfStartExiMessage exiMessage = NetconfStartExiMessage.create(EXIParameters.empty(), "msg-id");
        doReturn(promise).when(promise).setSuccess(anyObject());
        NetconfClientSessionNegotiator negotiator = createNetconfClientSessionNegotiator(promise, exiMessage);

        negotiator.channelActive(null);
        Set<String> caps = Sets.newSet("exi:1.0");
        NetconfHelloMessage message = NetconfHelloMessage.createServerHello(caps, 10);

        doAnswer(invocationOnMock -> {
            channelInboundHandlerAdapter = (ChannelInboundHandlerAdapter) invocationOnMock.getArguments()[2];
            return null;
        }).when(pipeline).addAfter(anyString(), anyString(), any(ChannelHandler.class));

        ChannelHandlerContext handlerContext = mock(ChannelHandlerContext.class);
        doReturn(pipeline).when(handlerContext).pipeline();
        negotiator.handleMessage(message);
        Document expectedResult = XmlFileLoader.xmlFileToDocument("netconfMessages/rpc-reply_ok.xml");
        channelInboundHandlerAdapter.channelRead(handlerContext, new NetconfMessage(expectedResult));

        verify(promise).setSuccess(anyObject());

        // two calls for exiMessage, 2 for hello message
        verify(pipeline, times(4)).replace(anyString(), anyString(), any(ChannelHandler.class));
    }

    @Test
    public void testNetconfClientSessionNegotiatorGetCached() throws Exception {
        Promise promise = mock(Promise.class);
        doReturn(promise).when(promise).setSuccess(anyObject());
        NetconfClientSessionListener sessionListener = mock(NetconfClientSessionListener.class);
        NetconfClientSessionNegotiator negotiator = createNetconfClientSessionNegotiator(promise, null);

        Set<String> set = createCapabilities("/helloMessage3.xml");

        final Set<String> cachedS1 = (Set<String>) negotiator.getSession(sessionListener, channel,
                createHelloMsg("/helloMessage1.xml")).getServerCapabilities();

        //helloMessage2 and helloMessage3 are the same with different order
        final Set<String> cachedS2 = (Set<String>) negotiator.getSession(sessionListener, channel,
                createHelloMsg("/helloMessage2.xml")).getServerCapabilities();
        final Set<String> cachedS3 = (Set<String>) negotiator.getSession(sessionListener, channel,
                createHelloMsg("/helloMessage3.xml")).getServerCapabilities();

        assertEquals(cachedS3, set);
        assertNotEquals(cachedS1, set);
        assertEquals(cachedS2, set);
        assertEquals(cachedS3, cachedS2);
        assertNotEquals(cachedS3, cachedS1);
        assertNotEquals(cachedS2, cachedS1);
        assertTrue(cachedS2 == cachedS3);
    }
}