//
//  ========================================================================
//  Copyright (c) 1995-2019 Mort Bay Consulting Pty. Ltd.
//  ------------------------------------------------------------------------
//  All rights reserved. This program and the accompanying materials
//  are made available under the terms of the Eclipse Public License v1.0
//  and Apache License v2.0 which accompanies this distribution.
//
//      The Eclipse Public License is available at
//      http://www.eclipse.org/legal/epl-v10.html
//
//      The Apache License v2.0 is available at
//      http://www.opensource.org/licenses/apache2.0.php
//
//  You may elect to redistribute this code under either of these licenses.
//  ========================================================================
//

package org.eclipse.jetty.server;
  
import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.is;
import static org.junit.jupiter.api.Assertions.fail;

import java.io.IOException;
import java.net.Socket;
import java.util.concurrent.Exchanger;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.function.Supplier;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.eclipse.jetty.http.HttpTester;
import org.eclipse.jetty.server.LocalConnector.LocalEndPoint;
import org.eclipse.jetty.server.handler.AbstractHandler;
import org.eclipse.jetty.util.BufferUtil;
import org.eclipse.jetty.util.log.Log;
import org.hamcrest.Matcher;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Disabled;
import org.junit.jupiter.api.Test;

public class NotAcceptingTest
{
    private final long IDLE_TIMEOUT = 2000;
    Server server;
    LocalConnector localConnector;
    ServerConnector blockingConnector;
    ServerConnector asyncConnector;

    @BeforeEach
    public void before()
    {
        server = new Server();
        
        localConnector = new LocalConnector(server);
        localConnector.setIdleTimeout(IDLE_TIMEOUT);
        server.addConnector(localConnector);
        
        blockingConnector = new ServerConnector(server,1,1);
        blockingConnector.setPort(0);
        blockingConnector.setIdleTimeout(IDLE_TIMEOUT);
        blockingConnector.setAcceptQueueSize(10);
        server.addConnector(blockingConnector);
        
        asyncConnector = new ServerConnector(server,0,1);
        asyncConnector.setPort(0);
        asyncConnector.setIdleTimeout(IDLE_TIMEOUT);
        asyncConnector.setAcceptQueueSize(10);
        server.addConnector(asyncConnector);
    }

    @AfterEach
    public void after() throws Exception
    {
        server.stop();
        server=null;
    }
    
    @Test
    public void testServerConnectorBlockingAccept() throws Exception
    {
        TestHandler handler = new TestHandler();
        server.setHandler(handler);

        server.start();
        
        try(Socket client0 = new Socket("localhost",blockingConnector.getLocalPort());)
        {
            HttpTester.Input in0 = HttpTester.from(client0.getInputStream());

            client0.getOutputStream().write("GET /one HTTP/1.1\r\nHost:localhost\r\n\r\n".getBytes());
            String uri = handler.exchange.exchange("data");
            assertThat(uri,is("/one"));
            HttpTester.Response response = HttpTester.parseResponse(in0);
            assertThat(response.getStatus(),is(200));
            assertThat(response.getContent(),is("data"));
            
            blockingConnector.setAccepting(false);

            // 0th connection still working
            client0.getOutputStream().write("GET /two HTTP/1.1\r\nHost:localhost\r\n\r\n".getBytes());
            uri = handler.exchange.exchange("more data");
            assertThat(uri,is("/two"));
            response = HttpTester.parseResponse(in0);
            assertThat(response.getStatus(),is(200));
            assertThat(response.getContent(),is("more data"));
            

            try(Socket client1 = new Socket("localhost",blockingConnector.getLocalPort());)
            {
                // can't stop next connection being accepted
                HttpTester.Input in1 = HttpTester.from(client1.getInputStream());
                client1.getOutputStream().write("GET /three HTTP/1.1\r\nHost:localhost\r\n\r\n".getBytes());
                uri = handler.exchange.exchange("new connection");
                assertThat(uri,is("/three"));
                response = HttpTester.parseResponse(in1);
                assertThat(response.getStatus(),is(200));
                assertThat(response.getContent(),is("new connection"));
                

                try(Socket client2 = new Socket("localhost",blockingConnector.getLocalPort());)
                {

                    HttpTester.Input in2 = HttpTester.from(client2.getInputStream());
                    client2.getOutputStream().write("GET /four HTTP/1.1\r\nHost:localhost\r\n\r\n".getBytes());

                    try
                    {
                        uri = handler.exchange.exchange("delayed connection",IDLE_TIMEOUT,TimeUnit.MILLISECONDS);
                        fail("Failed near URI: " + uri); // this displays last URI, not current (obviously)
                    }
                    catch(TimeoutException e)
                    {
                        // Can we accept the original?
                        blockingConnector.setAccepting(true); 
                        uri = handler.exchange.exchange("delayed connection");
                        assertThat(uri,is("/four"));
                        response = HttpTester.parseResponse(in2);
                        assertThat(response.getStatus(),is(200));
                        assertThat(response.getContent(),is("delayed connection"));
                    }
                }
            }
        }
    }
    

    @Test
    @Disabled
    public void testLocalConnector() throws Exception
    {
        server.setHandler(new HelloHandler());
        server.start();
        
        try(LocalEndPoint client0 = localConnector.connect())
        {
            client0.addInputAndExecute(BufferUtil.toBuffer("GET /one HTTP/1.1\r\nHost:localhost\r\n\r\n"));
            HttpTester.Response response = HttpTester.parseResponse(client0.getResponse());
            assertThat(response.getStatus(),is(200));
            assertThat(response.getContent(),is("Hello\n"));
                        
            localConnector.setAccepting(false);

            // 0th connection still working
            client0.addInputAndExecute(BufferUtil.toBuffer("GET /two HTTP/1.1\r\nHost:localhost\r\n\r\n"));
            response = HttpTester.parseResponse(client0.getResponse());
            assertThat(response.getStatus(),is(200));
            assertThat(response.getContent(),is("Hello\n"));
            
            LocalEndPoint[] local = new LocalEndPoint[10];
            for (int i = 0; i<10; i++)
            {
                try(LocalEndPoint client = localConnector.connect())
                {
                    try
                    {
                        local[i] = client;
                        client.addInputAndExecute(BufferUtil.toBuffer("GET /three HTTP/1.1\r\nHost:localhost\r\n\r\n"));
                        response = HttpTester.parseResponse(client.getResponse(false,IDLE_TIMEOUT,TimeUnit.MILLISECONDS));
                        
                        // A few local connections may succeed
                        if (i==local.length-1)
                            // but not 10 of them!
                            fail("Expected TimeoutException");
                    }
                    catch(TimeoutException e)
                    {
                        // A connection finally failed!
                        break;
                    }
                }   
            }
            // 0th connection still working
            client0.addInputAndExecute(BufferUtil.toBuffer("GET /four HTTP/1.1\r\nHost:localhost\r\n\r\n"));
            response = HttpTester.parseResponse(client0.getResponse());
            assertThat(response.getStatus(),is(200));
            assertThat(response.getContent(),is("Hello\n"));


            localConnector.setAccepting(true);
            // New connection working again
            try(LocalEndPoint client = localConnector.connect())
            {
                client.addInputAndExecute(BufferUtil.toBuffer("GET /five HTTP/1.1\r\nHost:localhost\r\n\r\n"));
                response = HttpTester.parseResponse(client.getResponse());
                assertThat(response.getStatus(),is(200));
                assertThat(response.getContent(),is("Hello\n"));
            }   
        }
    }
   
    @Test
    public void testServerConnectorAsyncAccept() throws Exception
    {
        TestHandler handler = new TestHandler();
        server.setHandler(handler);

        server.start();
        
        try(Socket client0 = new Socket("localhost",asyncConnector.getLocalPort());)
        {
            HttpTester.Input in0 = HttpTester.from(client0.getInputStream());

            client0.getOutputStream().write("GET /one HTTP/1.1\r\nHost:localhost\r\n\r\n".getBytes());
            String uri = handler.exchange.exchange("data");
            assertThat(uri,is("/one"));
            HttpTester.Response response = HttpTester.parseResponse(in0);
            assertThat(response.getStatus(),is(200));
            assertThat(response.getContent(),is("data"));
            
            asyncConnector.setAccepting(false);

            // 0th connection still working
            client0.getOutputStream().write("GET /two HTTP/1.1\r\nHost:localhost\r\n\r\n".getBytes());
            uri = handler.exchange.exchange("more data");
            assertThat(uri,is("/two"));
            response = HttpTester.parseResponse(in0);
            assertThat(response.getStatus(),is(200));
            assertThat(response.getContent(),is("more data"));
            

            try(Socket client1 = new Socket("localhost",asyncConnector.getLocalPort());)
            {
                HttpTester.Input in1 = HttpTester.from(client1.getInputStream());
                client1.getOutputStream().write("GET /three HTTP/1.1\r\nHost:localhost\r\n\r\n".getBytes());
                
                try
                {
                    uri = handler.exchange.exchange("delayed connection",IDLE_TIMEOUT,TimeUnit.MILLISECONDS);
                    fail(uri);
                }
                catch(TimeoutException e)
                {
                    // Can we accept the original?
                    asyncConnector.setAccepting(true); 
                    uri = handler.exchange.exchange("delayed connection");
                    assertThat(uri,is("/three"));
                    response = HttpTester.parseResponse(in1);
                    assertThat(response.getStatus(),is(200));
                    assertThat(response.getContent(),is("delayed connection"));
                }
            }
        }
    } 
    
    public static class TestHandler extends AbstractHandler
    {
        final Exchanger<String> exchange = new Exchanger<>();
        transient int handled;
        
        public TestHandler()
        {
        }

        @Override
        public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
        {
            try
            {
                String content = exchange.exchange(baseRequest.getRequestURI());
                baseRequest.setHandled(true);
                handled++;
                response.setContentType("text/html;charset=utf-8");
                response.setStatus(HttpServletResponse.SC_OK);
                response.getWriter().print(content);
            }
            catch (InterruptedException e)
            {
                throw new ServletException(e);
            }
        }
        
        public int getHandled()
        {
            return handled;
        }
    }
    
    @Test
    public void testAcceptRateLimit() throws Exception
    {
        AcceptRateLimit limit = new AcceptRateLimit(4,1,TimeUnit.HOURS, server);
        server.addBean(limit);
        server.setHandler(new HelloHandler());

        server.start();
        
        try (
            Socket async0 = new Socket("localhost",asyncConnector.getLocalPort());
            Socket async1 = new Socket("localhost",asyncConnector.getLocalPort());
            Socket async2 = new Socket("localhost",asyncConnector.getLocalPort());
            )
        {            
            String expectedContent = "Hello" + System.lineSeparator();

            for (Socket client : new Socket[]{async2})
            {
                HttpTester.Input in = HttpTester.from(client.getInputStream());
                client.getOutputStream().write("GET /test HTTP/1.1\r\nHost:localhost\r\n\r\n".getBytes());
                HttpTester.Response response = HttpTester.parseResponse(in);
                assertThat(response.getStatus(),is(200));
                assertThat(response.getContent(),is(expectedContent));
            }
            
            assertThat(localConnector.isAccepting(),is(true));
            assertThat(blockingConnector.isAccepting(),is(true));
            assertThat(asyncConnector.isAccepting(),is(true));
        }
        
        limit.age(45,TimeUnit.MINUTES);
        
        try (
            Socket async0 = new Socket("localhost",asyncConnector.getLocalPort());
            Socket async1 = new Socket("localhost",asyncConnector.getLocalPort());
            )
        {
            String expectedContent = "Hello" + System.lineSeparator();

            for (Socket client : new Socket[]{async1})
            {
                HttpTester.Input in = HttpTester.from(client.getInputStream());
                client.getOutputStream().write("GET /test HTTP/1.1\r\nHost:localhost\r\n\r\n".getBytes());
                HttpTester.Response response = HttpTester.parseResponse(in);
                assertThat(response.getStatus(),is(200));
                assertThat(response.getContent(),is(expectedContent));
            }
            
            assertThat(localConnector.isAccepting(),is(false));
            assertThat(blockingConnector.isAccepting(),is(false));
            assertThat(asyncConnector.isAccepting(),is(false));
        }

        limit.age(45,TimeUnit.MINUTES);
        assertThat(localConnector.isAccepting(),is(false));
        assertThat(blockingConnector.isAccepting(),is(false));
        assertThat(asyncConnector.isAccepting(),is(false));
        limit.run();
        assertThat(localConnector.isAccepting(),is(true));
        assertThat(blockingConnector.isAccepting(),is(true));
        assertThat(asyncConnector.isAccepting(),is(true));
    }


    @Test
    public void testConnectionLimit() throws Exception
    {
        server.addBean(new ConnectionLimit(9,server));
        server.setHandler(new HelloHandler());

        server.start();

        Log.getLogger(ConnectionLimit.class).debug("CONNECT:");
        try (
            LocalEndPoint local0 = localConnector.connect();
            LocalEndPoint local1 = localConnector.connect();
            LocalEndPoint local2 = localConnector.connect();
            Socket blocking0 = new Socket("localhost",blockingConnector.getLocalPort());
            Socket blocking1 = new Socket("localhost",blockingConnector.getLocalPort());
            Socket blocking2 = new Socket("localhost",blockingConnector.getLocalPort());
            Socket async0 = new Socket("localhost",asyncConnector.getLocalPort());
            Socket async1 = new Socket("localhost",asyncConnector.getLocalPort());
            Socket async2 = new Socket("localhost",asyncConnector.getLocalPort());
            )
        {
            String expectedContent = "Hello" + System.lineSeparator();

            Log.getLogger(ConnectionLimit.class).debug("LOCAL:");
            for (LocalEndPoint client: new LocalEndPoint[] {local0,local1,local2})
            {
                client.addInputAndExecute(BufferUtil.toBuffer("GET /test HTTP/1.1\r\nHost:localhost\r\n\r\n"));
                HttpTester.Response response = HttpTester.parseResponse(client.getResponse());
                assertThat(response.getStatus(),is(200));
                assertThat(response.getContent(),is(expectedContent));
            }
            
            Log.getLogger(ConnectionLimit.class).debug("NETWORK:");    
            for (Socket client : new Socket[]{blocking0,blocking1,blocking2,async0,async1,async2})
            {
                HttpTester.Input in = HttpTester.from(client.getInputStream());
                client.getOutputStream().write("GET /test HTTP/1.1\r\nHost:localhost\r\n\r\n".getBytes());
                HttpTester.Response response = HttpTester.parseResponse(in);
                assertThat(response.getStatus(),is(200));
                assertThat(response.getContent(),is(expectedContent));
            }
            
            assertThat(localConnector.isAccepting(),is(false));
            assertThat(blockingConnector.isAccepting(),is(false));
            assertThat(asyncConnector.isAccepting(),is(false));
            
            {
                // Close a async connection
                HttpTester.Input in = HttpTester.from(async1.getInputStream());
                async1.getOutputStream().write("GET /test HTTP/1.1\r\nHost:localhost\r\nConnection: close\r\n\r\n".getBytes());
                HttpTester.Response response = HttpTester.parseResponse(in);
                assertThat(response.getStatus(),is(200));
                assertThat(response.getContent(),is(expectedContent));
            }            
        }

        waitFor(localConnector::isAccepting,is(true),2*IDLE_TIMEOUT,TimeUnit.MILLISECONDS);
        waitFor(blockingConnector::isAccepting,is(true),2*IDLE_TIMEOUT,TimeUnit.MILLISECONDS);
        waitFor(asyncConnector::isAccepting,is(true),2*IDLE_TIMEOUT,TimeUnit.MILLISECONDS);
    }
    
    public static class HelloHandler extends AbstractHandler
    {
        public HelloHandler()
        {
        }

        @Override
        public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
        {
            baseRequest.setHandled(true);
            response.setContentType("text/html;charset=utf-8");
            response.setStatus(HttpServletResponse.SC_OK);
                response.getWriter().println("Hello");
        }
        
    }
    
    
    public static <T> void waitFor(Supplier<T> value, Matcher<T> matcher, long wait, TimeUnit units)
    {
        long start = System.nanoTime();
        
        while(true)
        {
            try
            {
                matcher.matches(value.get());
                return;
            }
            catch(Throwable e)
            {
                if ((System.nanoTime()-start) > units.toNanos(wait))
                    throw e;
            }
            
            try
            {
                TimeUnit.MILLISECONDS.sleep(50);
            }
            catch(InterruptedException e)
            {}            
        }
    }
}
