/*
 * ====================================================================
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.http.impl.nio.reactor;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.CodingErrorAction;

import org.apache.http.nio.reactor.SessionInputBuffer;
import org.apache.http.nio.reactor.SessionOutputBuffer;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpParams;
import org.apache.http.params.HttpProtocolParams;
import org.apache.http.util.CharArrayBuffer;
import org.junit.Assert;
import org.junit.Test;

/**
 * Simple tests for {@link SessionInputBuffer} and {@link SessionOutputBuffer}.
 */
public class TestSessionInOutBuffers {

    private static WritableByteChannel newChannel(final ByteArrayOutputStream outstream) {
        return Channels.newChannel(outstream);
    }

    private static ReadableByteChannel newChannel(final byte[] bytes) {
        return Channels.newChannel(new ByteArrayInputStream(bytes));
    }

    private static ReadableByteChannel newChannel(final String s, final String charset)
            throws UnsupportedEncodingException {
        return Channels.newChannel(new ByteArrayInputStream(s.getBytes(charset)));
    }

    private static ReadableByteChannel newChannel(final String s)
            throws UnsupportedEncodingException {
        return newChannel(s, "US-ASCII");
    }

    @Test
    public void testReadLineChunks() throws Exception {

        HttpParams params = new BasicHttpParams();
        SessionInputBuffer inbuf = new SessionInputBufferImpl(16, 16, params);

        ReadableByteChannel channel = newChannel("One\r\nTwo\r\nThree");

        inbuf.fill(channel);

        CharArrayBuffer line = new CharArrayBuffer(64);

        line.clear();
        Assert.assertTrue(inbuf.readLine(line, false));
        Assert.assertEquals("One", line.toString());

        line.clear();
        Assert.assertTrue(inbuf.readLine(line, false));
        Assert.assertEquals("Two", line.toString());

        line.clear();
        Assert.assertFalse(inbuf.readLine(line, false));

        channel = newChannel("\r\nFour");
        inbuf.fill(channel);

        line.clear();
        Assert.assertTrue(inbuf.readLine(line, false));
        Assert.assertEquals("Three", line.toString());

        inbuf.fill(channel);

        line.clear();
        Assert.assertTrue(inbuf.readLine(line, true));
        Assert.assertEquals("Four", line.toString());

        line.clear();
        Assert.assertFalse(inbuf.readLine(line, true));
    }

    @Test
    public void testWriteLineChunks() throws Exception {

        HttpParams params = new BasicHttpParams();
        SessionOutputBuffer outbuf = new SessionOutputBufferImpl(16, 16, params);
        SessionInputBuffer inbuf = new SessionInputBufferImpl(16, 16, params);

        ReadableByteChannel inChannel = newChannel("One\r\nTwo\r\nThree");

        inbuf.fill(inChannel);

        CharArrayBuffer line = new CharArrayBuffer(64);

        line.clear();
        Assert.assertTrue(inbuf.readLine(line, false));
        Assert.assertEquals("One", line.toString());

        outbuf.writeLine(line);

        line.clear();
        Assert.assertTrue(inbuf.readLine(line, false));
        Assert.assertEquals("Two", line.toString());

        outbuf.writeLine(line);

        line.clear();
        Assert.assertFalse(inbuf.readLine(line, false));

        inChannel = newChannel("\r\nFour");
        inbuf.fill(inChannel);

        line.clear();
        Assert.assertTrue(inbuf.readLine(line, false));
        Assert.assertEquals("Three", line.toString());

        outbuf.writeLine(line);

        inbuf.fill(inChannel);

        line.clear();
        Assert.assertTrue(inbuf.readLine(line, true));
        Assert.assertEquals("Four", line.toString());

        outbuf.writeLine(line);

        line.clear();
        Assert.assertFalse(inbuf.readLine(line, true));

        ByteArrayOutputStream outstream = new ByteArrayOutputStream();
        WritableByteChannel outChannel = newChannel(outstream);
        outbuf.flush(outChannel);

        String s = new String(outstream.toByteArray(), "US-ASCII");
        Assert.assertEquals("One\r\nTwo\r\nThree\r\nFour\r\n", s);
    }

    @Test
    public void testBasicReadWriteLine() throws Exception {

        String[] teststrs = new String[5];
        teststrs[0] = "Hello";
        teststrs[1] = "This string should be much longer than the size of the line buffer " +
                "which is only 16 bytes for this test";
        StringBuilder buffer = new StringBuilder();
        for (int i = 0; i < 15; i++) {
            buffer.append("123456789 ");
        }
        buffer.append("and stuff like that");
        teststrs[2] = buffer.toString();
        teststrs[3] = "";
        teststrs[4] = "And goodbye";

        HttpParams params = new BasicHttpParams();

        SessionOutputBuffer outbuf = new SessionOutputBufferImpl(1024, 16, params);
        for (int i = 0; i < teststrs.length; i++) {
            outbuf.writeLine(teststrs[i]);
        }
        //this write operation should have no effect
        outbuf.writeLine((String)null);
        outbuf.writeLine((CharArrayBuffer)null);

        ByteArrayOutputStream outstream = new ByteArrayOutputStream();
        WritableByteChannel outChannel = newChannel(outstream);
        outbuf.flush(outChannel);

        ReadableByteChannel channel = newChannel(outstream.toByteArray());

        SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 16, params);
        inbuf.fill(channel);

        for (int i = 0; i < teststrs.length; i++) {
            Assert.assertEquals(teststrs[i], inbuf.readLine(true));
        }
        Assert.assertNull(inbuf.readLine(true));
        Assert.assertNull(inbuf.readLine(true));
    }

    @Test
    public void testComplexReadWriteLine() throws Exception {
        HttpParams params = new BasicHttpParams();

        SessionOutputBuffer outbuf = new SessionOutputBufferImpl(1024, 16, params);
        outbuf.write(ByteBuffer.wrap(new byte[] {'a', '\n'}));
        outbuf.write(ByteBuffer.wrap(new byte[] {'\r', '\n'}));
        outbuf.write(ByteBuffer.wrap(new byte[] {'\r', '\r', '\n'}));
        outbuf.write(ByteBuffer.wrap(new byte[] {'\n'}));

        StringBuilder buffer = new StringBuilder();
        for (int i = 0; i < 14; i++) {
            buffer.append("a");
        }
        String s1 = buffer.toString();
        buffer.append("\r\n");
        outbuf.write(ByteBuffer.wrap(buffer.toString().getBytes("US-ASCII")));

        buffer.setLength(0);
        for (int i = 0; i < 15; i++) {
            buffer.append("a");
        }
        String s2 = buffer.toString();
        buffer.append("\r\n");
        outbuf.write(ByteBuffer.wrap(buffer.toString().getBytes("US-ASCII")));

        buffer.setLength(0);
        for (int i = 0; i < 16; i++) {
            buffer.append("a");
        }
        String s3 = buffer.toString();
        buffer.append("\r\n");
        outbuf.write(ByteBuffer.wrap(buffer.toString().getBytes("US-ASCII")));

        outbuf.write(ByteBuffer.wrap(new byte[] {'a'}));

        ByteArrayOutputStream outstream = new ByteArrayOutputStream();
        WritableByteChannel outChannel = newChannel(outstream);
        outbuf.flush(outChannel);

        ReadableByteChannel channel = newChannel(outstream.toByteArray());

        SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 16, params);
        inbuf.fill(channel);

        Assert.assertEquals("a", inbuf.readLine(true));
        Assert.assertEquals("", inbuf.readLine(true));
        Assert.assertEquals("\r", inbuf.readLine(true));
        Assert.assertEquals("", inbuf.readLine(true));
        Assert.assertEquals(s1, inbuf.readLine(true));
        Assert.assertEquals(s2, inbuf.readLine(true));
        Assert.assertEquals(s3, inbuf.readLine(true));
        Assert.assertEquals("a", inbuf.readLine(true));
        Assert.assertNull(inbuf.readLine(true));
        Assert.assertNull(inbuf.readLine(true));
    }

    @Test
    public void testReadOneByte() throws Exception {
        // make the buffer larger than that of transmitter
        byte[] out = new byte[40];
        for (int i = 0; i < out.length; i++) {
            out[i] = (byte)('0' + i);
        }
        ReadableByteChannel channel = newChannel(out);
        HttpParams params = new BasicHttpParams();
        SessionInputBuffer inbuf = new SessionInputBufferImpl(16, 16, params);
        while (inbuf.fill(channel) > 0) {
        }

        byte[] in = new byte[40];
        for (int i = 0; i < in.length; i++) {
            in[i] = (byte)inbuf.read();
        }
        for (int i = 0; i < out.length; i++) {
            Assert.assertEquals(out[i], in[i]);
        }
    }

    @Test
    public void testReadByteBuffer() throws Exception {
        byte[] pattern = "0123456789ABCDEF".getBytes("US-ASCII");
        ReadableByteChannel channel = newChannel(pattern);
        HttpParams params = new BasicHttpParams();
        SessionInputBuffer inbuf = new SessionInputBufferImpl(4096, 1024, params);
        while (inbuf.fill(channel) > 0) {
        }
        ByteBuffer dst = ByteBuffer.allocate(10);
        Assert.assertEquals(10, inbuf.read(dst));
        dst.flip();
        Assert.assertEquals(dst, ByteBuffer.wrap(pattern, 0, 10));
        dst.clear();
        Assert.assertEquals(6, inbuf.read(dst));
        dst.flip();
        Assert.assertEquals(dst, ByteBuffer.wrap(pattern, 10, 6));
    }

    @Test
    public void testReadByteBufferWithMaxLen() throws Exception {
        byte[] pattern = "0123456789ABCDEF".getBytes("US-ASCII");
        ReadableByteChannel channel = newChannel(pattern);
        HttpParams params = new BasicHttpParams();
        SessionInputBuffer inbuf = new SessionInputBufferImpl(4096, 1024, params);
        while (inbuf.fill(channel) > 0) {
        }
        ByteBuffer dst = ByteBuffer.allocate(16);
        Assert.assertEquals(10, inbuf.read(dst, 10));
        dst.flip();
        Assert.assertEquals(dst, ByteBuffer.wrap(pattern, 0, 10));
        dst.clear();
        Assert.assertEquals(3, inbuf.read(dst, 3));
        dst.flip();
        Assert.assertEquals(dst, ByteBuffer.wrap(pattern, 10, 3));
        Assert.assertEquals(3, inbuf.read(dst, 20));
        dst.flip();
        Assert.assertEquals(dst, ByteBuffer.wrap(pattern, 13, 3));
    }

    @Test
    public void testReadToChannel() throws Exception {
        byte[] pattern = "0123456789ABCDEF".getBytes("US-ASCII");
        ReadableByteChannel channel = newChannel(pattern);
        HttpParams params = new BasicHttpParams();
        SessionInputBuffer inbuf = new SessionInputBufferImpl(4096, 1024, params);
        while (inbuf.fill(channel) > 0) {
        }

        ByteArrayOutputStream outstream = new ByteArrayOutputStream();
        WritableByteChannel dst = newChannel(outstream);

        Assert.assertEquals(16, inbuf.read(dst));
        Assert.assertEquals(ByteBuffer.wrap(pattern), ByteBuffer.wrap(outstream.toByteArray()));
    }

    @Test
    public void testReadToChannelWithMaxLen() throws Exception {
        byte[] pattern = "0123456789ABCDEF".getBytes("US-ASCII");
        ReadableByteChannel channel = newChannel(pattern);
        HttpParams params = new BasicHttpParams();
        SessionInputBuffer inbuf = new SessionInputBufferImpl(4096, 1024, params);
        while (inbuf.fill(channel) > 0) {
        }

        ByteArrayOutputStream outstream = new ByteArrayOutputStream();
        WritableByteChannel dst = newChannel(outstream);

        Assert.assertEquals(10, inbuf.read(dst, 10));
        Assert.assertEquals(3, inbuf.read(dst, 3));
        Assert.assertEquals(3, inbuf.read(dst, 10));
        Assert.assertEquals(ByteBuffer.wrap(pattern), ByteBuffer.wrap(outstream.toByteArray()));
    }

    @Test
    public void testWriteByteBuffer() throws Exception {
        byte[] pattern = "0123456789ABCDEF0123456789ABCDEF".getBytes("US-ASCII");

        HttpParams params = new BasicHttpParams();
        SessionOutputBuffer outbuf = new SessionOutputBufferImpl(4096, 1024, params);
        ReadableByteChannel src = newChannel(pattern);
        outbuf.write(src);

        ByteArrayOutputStream outstream = new ByteArrayOutputStream();
        WritableByteChannel channel = newChannel(outstream);
        while (outbuf.flush(channel) > 0) {
        }
        Assert.assertEquals(ByteBuffer.wrap(pattern), ByteBuffer.wrap(outstream.toByteArray()));
    }

    @Test
    public void testWriteFromChannel() throws Exception {
        byte[] pattern = "0123456789ABCDEF0123456789ABCDEF".getBytes("US-ASCII");

        HttpParams params = new BasicHttpParams();
        SessionOutputBuffer outbuf = new SessionOutputBufferImpl(4096, 1024, params);
        outbuf.write(ByteBuffer.wrap(pattern, 0, 16));
        outbuf.write(ByteBuffer.wrap(pattern, 16, 10));
        outbuf.write(ByteBuffer.wrap(pattern, 26, 6));

        ByteArrayOutputStream outstream = new ByteArrayOutputStream();
        WritableByteChannel channel = newChannel(outstream);
        while (outbuf.flush(channel) > 0) {
        }
        Assert.assertEquals(ByteBuffer.wrap(pattern), ByteBuffer.wrap(outstream.toByteArray()));
    }

    static final int SWISS_GERMAN_HELLO [] = {
        0x47, 0x72, 0xFC, 0x65, 0x7A, 0x69, 0x5F, 0x7A, 0xE4, 0x6D, 0xE4
    };

    static final int RUSSIAN_HELLO [] = {
        0x412, 0x441, 0x435, 0x43C, 0x5F, 0x43F, 0x440, 0x438,
        0x432, 0x435, 0x442
    };

    private static String constructString(int [] unicodeChars) {
        StringBuilder buffer = new StringBuilder();
        if (unicodeChars != null) {
            for (int i = 0; i < unicodeChars.length; i++) {
                buffer.append((char)unicodeChars[i]);
            }
        }
        return buffer.toString();
    }

    @Test
    public void testMultibyteCodedReadWriteLine() throws Exception {
        String s1 = constructString(SWISS_GERMAN_HELLO);
        String s2 = constructString(RUSSIAN_HELLO);
        String s3 = "Like hello and stuff";

        HttpParams params = new BasicHttpParams();
        HttpProtocolParams.setHttpElementCharset(params, "UTF-8");

        SessionOutputBuffer outbuf = new SessionOutputBufferImpl(1024, 16, params);

        for (int i = 0; i < 10; i++) {
            outbuf.writeLine(s1);
            outbuf.writeLine(s2);
            outbuf.writeLine(s3);
        }

        ByteArrayOutputStream outstream = new ByteArrayOutputStream();
        WritableByteChannel outChannel = newChannel(outstream);
        outbuf.flush(outChannel);

        byte[] tmp = outstream.toByteArray();

        ReadableByteChannel channel = newChannel(tmp);
        SessionInputBuffer inbuf = new SessionInputBufferImpl(16, 16, params);

        while (inbuf.fill(channel) > 0) {
        }

        for (int i = 0; i < 10; i++) {
            Assert.assertEquals(s1, inbuf.readLine(true));
            Assert.assertEquals(s2, inbuf.readLine(true));
            Assert.assertEquals(s3, inbuf.readLine(true));
        }
    }

    @Test
    public void testMalformedCharacters() throws Exception {
        HttpParams params = new BasicHttpParams();
        String s1 = constructString(SWISS_GERMAN_HELLO);
        SessionOutputBuffer outbuf = new SessionOutputBufferImpl(1024, 16, params);
        try {
            outbuf.writeLine(s1);
            Assert.fail("Expected CharacterCodingException");
        } catch (CharacterCodingException expected) {
        }

        byte[] tmp = s1.getBytes("ISO-8859-1");
        ReadableByteChannel channel = newChannel(tmp);
        SessionInputBuffer inbuf = new SessionInputBufferImpl(16, 16, params);
        while (inbuf.fill(channel) > 0) {
        }

        try {
            String s = inbuf.readLine(true);
            Assert.fail("Expected CharacterCodingException, got '" + s + "'");
        } catch (CharacterCodingException expected) {
        }
    }

    @Test
    public void testInputMatchesBufferLength() throws Exception {
        HttpParams params = new BasicHttpParams();
        String s1 = "abcde";
        SessionOutputBuffer outbuf = new SessionOutputBufferImpl(1024, 5, params);
        outbuf.writeLine(s1);
    }

    @Test
    public void testMalformedInputAction() throws Exception {
        HttpParams params = new BasicHttpParams();
        String s1 = constructString(SWISS_GERMAN_HELLO);

        byte[] tmp = s1.getBytes("ISO-8859-1");
        ReadableByteChannel channel = newChannel(tmp);
        SessionInputBuffer inbuf = new SessionInputBufferImpl(16, 16, params);
        while (inbuf.fill(channel) > 0) {
        }

        // Action with report
        HttpProtocolParams.setMalformedInputAction(params, CodingErrorAction.REPORT);
        try {
            String s = inbuf.readLine(true);
            Assert.fail("Expected CharacterCodingException, got '" + s + "'");
        } catch (CharacterCodingException expected) {
        }

        // Action with ignore
        HttpProtocolParams.setMalformedInputAction(params, CodingErrorAction.IGNORE);
        inbuf = new SessionInputBufferImpl(16, 16, params);
        String s2 = null;
        try {
            s2 = inbuf.readLine(true);
        } catch (CharacterCodingException e) {
            Assert.fail("Unexpected CharacterCodingException " +
                    (s2 == null ? "" : ", got '" + s2 + "'"));
        }

        // Action with replace
        HttpProtocolParams.setMalformedInputAction(params, CodingErrorAction.REPLACE);
        inbuf = new SessionInputBufferImpl(16, 16, params);
        String s3 = null;
        try {
            s3 = inbuf.readLine(true);
        } catch (CharacterCodingException e) {
            Assert.fail("Unexpected CharacterCodingException " +
                    (s3 == null ? "" : ", got '" + s3 + "'"));
        }
    }

    @Test
    public void testUnmappableInputAction() throws Exception {
        HttpParams params = new BasicHttpParams();
        String s1 = constructString(SWISS_GERMAN_HELLO);

        // Action with report
        HttpProtocolParams.setUnmappableInputAction(params, CodingErrorAction.REPORT);
        SessionOutputBuffer outbuf = new SessionOutputBufferImpl(1024, 16, params);
        try {
            outbuf.writeLine(s1);
            Assert.fail("Expected CharacterCodingException");
        } catch (CharacterCodingException expected) {
        }

        // Action with ignore
        HttpProtocolParams.setUnmappableInputAction(params, CodingErrorAction.IGNORE);
        outbuf = new SessionOutputBufferImpl(1024, 16, params);
        try {
            outbuf.writeLine(s1);
        } catch (CharacterCodingException e) {
            Assert.fail("Unexpected CharacterCodingException");
        }

        // Action with replace
        HttpProtocolParams.setUnmappableInputAction(params, CodingErrorAction.REPLACE);
        outbuf = new SessionOutputBufferImpl(1024, 16, params);
        try {
            outbuf.writeLine(s1);
        } catch (CharacterCodingException e) {
            Assert.fail("Unexpected CharacterCodingException");
        }
    }

}