/*

 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

import java.io.ByteArrayOutputStream;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.Reader;

import java.io.Writer;

import java.nio.channels.Channels;

import java.nio.channels.ReadableByteChannel;

import java.nio.channels.WritableByteChannel;

import java.nio.charset.Charset;

import java.nio.charset.MalformedInputException;

import java.nio.charset.StandardCharsets;

import java.nio.file.Paths;

import org.testng.Assert;

import org.testng.annotations.DataProvider;

import org.testng.annotations.Test;

/**

 * @test

 * @bug 8183743

 * @summary Test to verify the new overload method with Charset functions the same

 * as the existing method that takes a charset name.

 * @run testng EncodingTest

 */

public class EncodingTest {

    static final int ITERATIONS = 2;

    public static final String CS_UTF8 = StandardCharsets.UTF_8.name();

    public static final String CS_ISO8859 = StandardCharsets.ISO_8859_1.name();

    static String USER_DIR = System.getProperty("user.dir", ".");

    // malformed input: a high surrogate without the low surrogate

    static char[] illChars = {

        '\u00fa', '\ud800'

    };

    static byte[] data = getData();

    static byte[] getData() {

        try {

            String str1 = "A string that contains ";

            String str2 = " , an invalid character for UTF-8.";

            ByteArrayOutputStream baos = new ByteArrayOutputStream();

            baos.write(str1.getBytes());

            baos.write(0xFA);

            baos.write(str2.getBytes());

            return baos.toByteArray();

        } catch (IOException ex) {

            return null; //shouldn't happen

        }

    }

    String testFile = Paths.get(USER_DIR, "channelsEncodingTest.txt").toString();

    String testIllegalInput = Paths.get(USER_DIR, "channelsIllegalInputTest.txt").toString();

    String testIllegalOutput = Paths.get(USER_DIR, "channelsIllegalOutputTest.txt").toString();

    /*

     * DataProvider for read and write test.

     * Writes and reads with the same encoding

     */

    @DataProvider(name = "writeAndRead")

    public Object[][] getWRParameters() {

        return new Object[][]{

            {testFile, StandardCharsets.ISO_8859_1.name(), null,

                StandardCharsets.ISO_8859_1.name(), StandardCharsets.ISO_8859_1},

            {testFile, null, StandardCharsets.ISO_8859_1,

                StandardCharsets.ISO_8859_1.name(), StandardCharsets.ISO_8859_1},

            {testFile, StandardCharsets.UTF_8.name(), null,

                StandardCharsets.UTF_8.name(), StandardCharsets.UTF_8},

            {testFile, null, StandardCharsets.UTF_8,

                StandardCharsets.UTF_8.name(), StandardCharsets.UTF_8}

        };

    }

    /*

     * DataProvider for illegal input test

     * Writes the data in ISO8859 and reads with UTF8, expects MalformedInputException

     */

    @DataProvider(name = "illegalInput")

    public Object[][] getParameters() {

        return new Object[][]{

            {testIllegalInput, StandardCharsets.ISO_8859_1.name(), null, StandardCharsets.UTF_8.name(), null},

            {testIllegalInput, StandardCharsets.ISO_8859_1.name(), null, null, StandardCharsets.UTF_8},

            {testIllegalInput, null, StandardCharsets.ISO_8859_1, StandardCharsets.UTF_8.name(), null},

            {testIllegalInput, null, StandardCharsets.ISO_8859_1, null, StandardCharsets.UTF_8},

        };

    }

    /*

     * DataProvider for illegal output test

     * Attemps to write some malformed chars, expects MalformedInputException

     */

    @DataProvider(name = "illegalOutput")

    public Object[][] getWriteParameters() {

        return new Object[][]{

            {testIllegalOutput, StandardCharsets.UTF_8.name(), null},

            {testIllegalOutput, null, StandardCharsets.UTF_8}

        };

    }

    /**

     * Verifies that the Readers created with the following methods are

     * equivalent:

     * newReader(ReadableByteChannel ch, String csName)

     * newReader(ReadableByteChannel ch, Charset charset)

     *

     * The verification follows the following steps:

     * Writes a file with a writer created with the specified charset

     * Reads it with a reader created with newReader using the same charset;

     * Compares that the results are the same.

     *

     * @param file the file name

     * @param csnWriter the charset name for creating the writer

     * @param charsetWriter the charset for creating the writer

     * @param csnReader the charset name for creating the reader

     * @param charsetReader the charset for creating the reader

     * @throws Exception

     */

    @Test(dataProvider = "writeAndRead")

    public void testWriteAndRead(String file, String csnWriter, Charset charsetWriter,

            String csnReader, Charset charsetReader) throws Exception {

        writeToFile(data, file, csnWriter, charsetWriter);

        // read using charset name

        String result1 = readFileToString(file, csnReader, null);

        String result2 = readFileToString(file, null, charsetReader);

        Assert.assertEquals(result1, result2);

    }

    /**

     * Verifies that MalformedInputException is thrown when an input byte sequence

     * is illegal for given charset that is configured for the reader.

     *

     * @param file the file to be read

     * @param csnWriter the charset name for creating the writer

     * @param charsetWriter the charset for creating the writer

     * @param csnReader the charset name for creating the reader

     * @param charsetReader the charset for creating the reader

     * @throws Exception

     */

    @Test(dataProvider = "illegalInput", expectedExceptions = MalformedInputException.class)

    void testMalformedInput(String file, String csnWriter, Charset charsetWriter,

            String csnReader, Charset charsetReader) throws Exception {

        writeToFile(data, file, csnWriter, charsetWriter);

        readFileToString(file, csnReader, charsetReader);

    }

    /**

     * Attempts to write illegal characters using a writer created by calling

     * the newWriter method and expects a MalformedInputException.

     *

     * @param fileName the file name

     * @param csn the charset name

     * @param charset the charset

     * @throws Exception

     */

    @Test(dataProvider = "illegalOutput", expectedExceptions = MalformedInputException.class)

    public void testMalformedOutput(String fileName, String csn, Charset charset)

            throws Exception {

        try (FileOutputStream fos = new FileOutputStream(fileName);

                WritableByteChannel wbc = (WritableByteChannel) fos.getChannel();) {

            Writer writer;

            if (csn != null) {

                writer = Channels.newWriter(wbc, csn);

            } else {

                writer = Channels.newWriter(wbc, charset);

            }

            for (int i = 0; i < ITERATIONS; i++) {

                writer.write(illChars);

            }

            writer.flush();

            writer.close();

        }

    }

    /**

     * Writes the data to a file using a writer created by calling the newWriter

     * method.

     *

     * @param data the data to be written

     * @param fileName the file name

     * @param csn the charset name

     * @param charset the charset

     * @throws Exception

     */

    private void writeToFile(byte[] data, String fileName, String csn, Charset charset) throws Exception {

        try (FileOutputStream fos = new FileOutputStream(fileName);

                WritableByteChannel wbc = (WritableByteChannel) fos.getChannel()) {

            Writer writer;

            String temp;

            if (csn != null) {

                writer = Channels.newWriter(wbc, csn);

                temp = new String(data, csn);

            } else {

                writer = Channels.newWriter(wbc, charset);

                temp = new String(data, charset);

            }

            for (int i = 0; i < ITERATIONS; i++) {

                writer.write(temp);

            }

            writer.flush();

            writer.close();

        }

    }

    /**

     * Reads a file into a String.

     *

     * @param file the file to be read

     * @param csn the charset name

     * @param charset the charset

     * @throws Exception

     */

    String readFileToString(String file, String csn, Charset charset) throws Exception {

        String result;

        try (FileInputStream fis = new FileInputStream(file);

                ReadableByteChannel rbc = (ReadableByteChannel) fis.getChannel()) {

            Reader reader;

            if (csn != null) {

                reader = Channels.newReader(rbc, csn);

            } else {

                reader = Channels.newReader(rbc, charset);

            }

            int messageSize = data.length * ITERATIONS;

            char data1[] = new char[messageSize];

            int totalRead = 0;

            int charsRead = 0;

            while (totalRead < messageSize) {

                totalRead += charsRead;

                charsRead = reader.read(data1, totalRead, messageSize - totalRead);

            }

            result = new String(data1, 0, totalRead);

            reader.close();

        }

        return result;

    }

}