/*

 * Copyright (c) 2018, 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.File;

import java.io.FileInputStream;

import java.io.FileReader;

import java.io.FileWriter;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.Reader;

import java.nio.charset.Charset;

import java.nio.charset.StandardCharsets;

import org.testng.Assert;

import org.testng.annotations.DataProvider;

import org.testng.annotations.Test;

/**

 * @test

 * @bug 8183554

 * @summary Test to verify the new Constructors that take a Charset.

 * @run testng ConstructorTest

 */

public class ConstructorTest {

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

    public static enum ConstructorType {

        STRING,

        FILE

    }

    static final String TEST_STRING = "abc \u0100 \u0101 \u0555 \u07FD \u07FF";

    static final int BUFFER_SIZE = 8192;

    @DataProvider(name = "parameters")

    public Object[][] getParameters() throws IOException {

        File file1 = new File(USER_DIR, "FileReaderTest1.txt");

        File file2 = new File(USER_DIR, "FileReaderTest2.txt");

        return new Object[][]{

            {ConstructorType.STRING, file1, file2, StandardCharsets.UTF_8},

            {ConstructorType.FILE, file1, file2, StandardCharsets.UTF_8},

            {ConstructorType.STRING, file1, file2, StandardCharsets.ISO_8859_1},

            {ConstructorType.FILE, file1, file2, StandardCharsets.ISO_8859_1},

        };

    }

    /**

     * Verifies that the new constructors that take a Charset function the same

     * as an InputStreamReader on a FileInputStream as was recommended before

     * this change.

     *

     * @param type the type of the constructor

     * @param file1 file1 to be read with a FileReader

     * @param file2 file2 to be read with an InputStreamReader

     * @param charset the charset

     * @throws IOException

     */

    @Test(dataProvider = "parameters")

    void test(ConstructorType type, File file1, File file2, Charset charset)

            throws Exception {

        prepareFile(file1, TEST_STRING, charset);

        prepareFile(file2, TEST_STRING, charset);

        try (FileReader fr = getFileReader(type, file1, charset);

                FileInputStream is = new FileInputStream(file2);

                InputStreamReader isr = new InputStreamReader(is, charset);) {

            String result1 = readAll(fr, BUFFER_SIZE);

            String result2 = readAll(isr, BUFFER_SIZE);

            Assert.assertEquals(result1, result2);

        }

    }

    public String readAll(Reader reader, int bufferSize) throws IOException {

        StringBuilder sb = new StringBuilder();

        char[] buf = new char[bufferSize];

        int numRead;

        while ((numRead = reader.read(buf)) != -1) {

            if (numRead == buf.length) {

                sb.append(buf);

            } else {

                sb.append(String.valueOf(buf, 0, numRead));

            }

        }

        return sb.toString();

    }

    /*

     * Creates a FileReader over the given input file.

     */

    FileReader getFileReader(ConstructorType type, File file, Charset charset)

            throws IOException {

        switch (type) {

            case STRING:

                return new FileReader(file.getPath(), charset);

            case FILE:

                return new FileReader(file, charset);

        }

        return null;

    }

    void prepareFile(File file, String content, Charset charset) throws IOException {

        try (FileWriter writer = new FileWriter(file, charset);) {

            writer.write(content);

        }

    }

}