//
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//  Copyright (c) 1995-2020 Mort Bay Consulting Pty Ltd and others.
//  ------------------------------------------------------------------------
//  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
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//      The Apache License v2.0 is available at
//      http://www.opensource.org/licenses/apache2.0.php
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//  You may elect to redistribute this code under either of these licenses.
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package org.eclipse.jetty.server.handler;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;

import org.eclipse.jetty.http.HttpStatus;
import org.eclipse.jetty.http.HttpTester;
import org.eclipse.jetty.server.Connector;
import org.eclipse.jetty.server.HttpConfiguration;
import org.eclipse.jetty.server.HttpConnectionFactory;
import org.eclipse.jetty.server.LocalConnector;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.ServerConnector;
import org.eclipse.jetty.toolchain.test.MavenTestingUtils;
import org.eclipse.jetty.util.BufferUtil;
import org.eclipse.jetty.util.IO;
import org.hamcrest.Matchers;
import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.condition.DisabledIfSystemProperty;

import static org.eclipse.jetty.http.HttpHeader.CONTENT_LENGTH;
import static org.eclipse.jetty.http.HttpHeader.CONTENT_TYPE;
import static org.eclipse.jetty.http.HttpHeader.LAST_MODIFIED;
import static org.eclipse.jetty.http.HttpHeader.LOCATION;
import static org.eclipse.jetty.http.HttpHeader.SERVER;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.containsString;
import static org.hamcrest.Matchers.endsWith;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.startsWith;
import static org.junit.jupiter.api.Assertions.assertEquals;

/**
 * Resource Handler test
 *
 * TODO: increase the testing going on here
 */
public class ResourceHandlerTest
{
    private static String LN = System.getProperty("line.separator");
    private static Server _server;
    private static HttpConfiguration _config;
    private static ServerConnector _connector;
    private static LocalConnector _local;
    private static ContextHandler _contextHandler;
    private static ResourceHandler _resourceHandler;

    @BeforeAll
    public static void setUp() throws Exception
    {
        File dir = MavenTestingUtils.getTargetFile("test-classes/simple");
        File bigger = new File(dir, "bigger.txt");
        File big = new File(dir, "big.txt");
        try (OutputStream out = new FileOutputStream(bigger))
        {
            for (int i = 0; i < 100; i++)
            {
                try (InputStream in = new FileInputStream(big))
                {
                    IO.copy(in, out);
                }
            }
        }

        bigger.deleteOnExit();

        // determine how the SCM of choice checked out the big.txt EOL
        // we can't just use whatever is the OS default.
        // because, for example, a windows system using git can be configured for EOL handling using
        // local, remote, file lists, patterns, etc, rendering assumptions about the OS EOL choice
        // wrong for unit tests.
        LN = System.getProperty("line.separator");
        try (BufferedReader reader = Files.newBufferedReader(big.toPath(), StandardCharsets.UTF_8))
        {
            // a buffer large enough to capture at least 1 EOL
            char[] cbuf = new char[128];
            reader.read(cbuf);
            String sample = new String(cbuf);
            if (sample.contains("\r\n"))
            {
                LN = "\r\n";
            }
            else if (sample.contains("\n\r"))
            {
                LN = "\n\r";
            }
            else
            {
                LN = "\n";
            }
        }

        _server = new Server();
        _config = new HttpConfiguration();
        _config.setOutputBufferSize(2048);
        _connector = new ServerConnector(_server, new HttpConnectionFactory(_config));

        _local = new LocalConnector(_server);

        _server.setConnectors(new Connector[]{_connector, _local});

        _resourceHandler = new ResourceHandler();

        _resourceHandler.setResourceBase(MavenTestingUtils.getTargetFile("test-classes/simple").getAbsolutePath());
        _resourceHandler.setWelcomeFiles(new String[]{"welcome.txt"});

        _contextHandler = new ContextHandler("/resource");
        _contextHandler.setHandler(_resourceHandler);
        _server.setHandler(_contextHandler);
        _server.start();
    }

    @AfterAll
    public static void tearDown() throws Exception
    {
        _server.stop();
    }

    @BeforeEach
    public void before()
    {
        _config.setOutputBufferSize(4096);
    }

    @Test
    public void testJettyDirRedirect() throws Exception
    {
        HttpTester.Response response = HttpTester.parseResponse(
            _local.getResponse("GET /resource HTTP/1.0\r\n\r\n"));
        assertThat(response.getStatus(), equalTo(302));
        assertThat(response.get(LOCATION), containsString("/resource/"));
    }

    @Test
    public void testJettyDirListing() throws Exception
    {
        HttpTester.Response response = HttpTester.parseResponse(
            _local.getResponse("GET /resource/ HTTP/1.0\r\n\r\n"));
        assertThat(response.getStatus(), equalTo(200));
        assertThat(response.getContent(), containsString("jetty-dir.css"));
        assertThat(response.getContent(), containsString("Directory: /resource/"));
        assertThat(response.getContent(), containsString("big.txt"));
        assertThat(response.getContent(), containsString("bigger.txt"));
        assertThat(response.getContent(), containsString("directory"));
        assertThat(response.getContent(), containsString("simple.txt"));
    }

    @Test
    public void testHeaders() throws Exception
    {
        HttpTester.Response response = HttpTester.parseResponse(
            _local.getResponse("GET /resource/simple.txt HTTP/1.0\r\n\r\n"));
        assertThat(response.getStatus(), equalTo(200));
        assertThat(response.get(CONTENT_TYPE), equalTo("text/plain"));
        assertThat(response.get(LAST_MODIFIED), Matchers.notNullValue());
        assertThat(response.get(CONTENT_LENGTH), equalTo("11"));
        assertThat(response.get(SERVER), containsString("Jetty"));
        assertThat(response.getContent(), containsString("simple text"));
    }

    @Test
    public void testIfModifiedSince() throws Exception
    {
        HttpTester.Response response = HttpTester.parseResponse(
            _local.getResponse("GET /resource/simple.txt HTTP/1.0\r\n\r\n"));
        assertThat(response.getStatus(), equalTo(200));
        assertThat(response.get(LAST_MODIFIED), Matchers.notNullValue());
        assertThat(response.getContent(), containsString("simple text"));
        String lastModified = response.get(LAST_MODIFIED);

        response = HttpTester.parseResponse(_local.getResponse(
            "GET /resource/simple.txt HTTP/1.0\r\n" +
                "If-Modified-Since: " + lastModified + "\r\n" +
                "\r\n"));

        assertThat(response.getStatus(), equalTo(304));
    }

    @Test
    public void testBigFile() throws Exception
    {
        _config.setOutputBufferSize(2048);

        HttpTester.Response response = HttpTester.parseResponse(
            _local.getResponse("GET /resource/big.txt HTTP/1.0\r\n\r\n"));
        assertThat(response.getStatus(), equalTo(200));
        assertThat(response.getContent(), startsWith("     1\tThis is a big file"));
        assertThat(response.getContent(), endsWith("   400\tThis is a big file" + LN));
    }

    @Test
    public void testBigFileBigBuffer() throws Exception
    {
        _config.setOutputBufferSize(16 * 1024);

        HttpTester.Response response = HttpTester.parseResponse(
            _local.getResponse("GET /resource/big.txt HTTP/1.0\r\n\r\n"));
        assertThat(response.getStatus(), equalTo(200));
        assertThat(response.getContent(), startsWith("     1\tThis is a big file"));
        assertThat(response.getContent(), endsWith("   400\tThis is a big file" + LN));
    }

    @Test
    public void testBigFileLittleBuffer() throws Exception
    {
        _config.setOutputBufferSize(8);

        HttpTester.Response response = HttpTester.parseResponse(
            _local.getResponse("GET /resource/big.txt HTTP/1.0\r\n\r\n"));
        assertThat(response.getStatus(), equalTo(200));
        assertThat(response.getContent(), startsWith("     1\tThis is a big file"));
        assertThat(response.getContent(), endsWith("   400\tThis is a big file" + LN));
    }

    @Test
    public void testBigger() throws Exception
    {
        try (Socket socket = new Socket("localhost", _connector.getLocalPort());)
        {
            socket.getOutputStream().write("GET /resource/bigger.txt HTTP/1.0\n\n".getBytes());
            Thread.sleep(1000);
            String response = IO.toString(socket.getInputStream());
            assertThat(response, Matchers.startsWith("HTTP/1.1 200 OK"));
            assertThat(response, Matchers.containsString("   400\tThis is a big file" + LN + "     1\tThis is a big file"));
            assertThat(response, Matchers.endsWith("   400\tThis is a big file" + LN));
        }
    }

    @Test
    public void testWelcome() throws Exception
    {
        HttpTester.Response response = HttpTester.parseResponse(
            _local.getResponse("GET /resource/directory/ HTTP/1.0\r\n\r\n"));
        assertThat(response.getStatus(), equalTo(200));
        assertThat(response.getContent(), containsString("Hello"));
    }

    @Test
    public void testWelcomeRedirect() throws Exception
    {
        try
        {
            _resourceHandler.setRedirectWelcome(true);
            HttpTester.Response response = HttpTester.parseResponse(
                _local.getResponse("GET /resource/directory/ HTTP/1.0\r\n\r\n"));
            assertThat(response.getStatus(), equalTo(302));
            assertThat(response.get(LOCATION), containsString("/resource/directory/welcome.txt"));
        }
        finally
        {
            _resourceHandler.setRedirectWelcome(false);
        }
    }

    @Test
    @DisabledIfSystemProperty(named = "env", matches = "ci") // TODO: SLOW, needs review
    public void testSlowBiggest() throws Exception
    {
        _connector.setIdleTimeout(9000);

        File dir = MavenTestingUtils.getTargetFile("test-classes/simple");
        File biggest = new File(dir, "biggest.txt");
        try (OutputStream out = new FileOutputStream(biggest))
        {
            for (int i = 0; i < 10; i++)
            {
                try (InputStream in = new FileInputStream(new File(dir, "bigger.txt")))
                {
                    IO.copy(in, out);
                }
            }
            out.write("\nTHE END\n".getBytes(StandardCharsets.ISO_8859_1));
        }
        biggest.deleteOnExit();

        try (Socket socket = new Socket("localhost", _connector.getLocalPort());
             OutputStream out = socket.getOutputStream();
             InputStream in = socket.getInputStream())
        {
            socket.getOutputStream().write("GET /resource/biggest.txt HTTP/1.0\n\n".getBytes());

            byte[] array = new byte[102400];
            ByteBuffer buffer = null;
            while (true)
            {
                Thread.sleep(25);
                int len = in.read(array);
                if (len < 0)
                    break;
                buffer = BufferUtil.toBuffer(array, 0, len);
                // System.err.println(++i+": "+BufferUtil.toDetailString(buffer));
            }

            assertEquals('E', buffer.get(buffer.limit() - 4));
            assertEquals('N', buffer.get(buffer.limit() - 3));
            assertEquals('D', buffer.get(buffer.limit() - 2));
        }
    }

    @Test
    public void testConditionalGetResponseCommitted() throws Exception
    {
        _config.setOutputBufferSize(8);
        _resourceHandler.setEtags(true);

        HttpTester.Response response = HttpTester.parseResponse(_local.getResponse("GET /resource/big.txt HTTP/1.0\r\n" +
            "If-Match: \"NO_MATCH\"\r\n" +
            "\r\n"));

        assertThat(response.getStatus(), equalTo(HttpStatus.PRECONDITION_FAILED_412));
    }

    @Test
    public void testConditionalHeadResponseCommitted() throws Exception
    {
        _config.setOutputBufferSize(8);
        _resourceHandler.setEtags(true);

        HttpTester.Response response = HttpTester.parseResponse(_local.getResponse("HEAD /resource/big.txt HTTP/1.0\r\n" +
            "If-Match: \"NO_MATCH\"\r\n" +
            "\r\n"));

        assertThat(response.getStatus(), equalTo(HttpStatus.PRECONDITION_FAILED_412));
    }
}
