/*
 *  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.
 *
 */

package org.apache.tools.zip;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;
import java.util.Collections;
import java.util.zip.CRC32;
import org.junit.Test;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;

public class UTF8ZipFilesTest {

    private static final String UTF_8 = "utf-8";
    private static final String CP437 = "cp437";
    private static final String US_ASCII = "US-ASCII";
    private static final String ASCII_TXT = "ascii.txt";
    private static final String EURO_FOR_DOLLAR_TXT = "\u20AC_for_Dollar.txt";
    private static final String OIL_BARREL_TXT = "\u00D6lf\u00E4sser.txt";

    @Test
    public void testUtf8FileRoundtripExplicitUnicodeExtra()
        throws IOException {
        testFileRoundtrip(UTF_8, true, true);
    }

    @Test
    public void testUtf8FileRoundtripNoEFSExplicitUnicodeExtra()
        throws IOException {
        testFileRoundtrip(UTF_8, false, true);
    }

    @Test
    public void testCP437FileRoundtripExplicitUnicodeExtra()
        throws IOException {
        testFileRoundtrip(CP437, false, true);
    }

    @Test
    public void testASCIIFileRoundtripExplicitUnicodeExtra()
        throws IOException {
        testFileRoundtrip(US_ASCII, false, true);
    }

    @Test
    public void testUtf8FileRoundtripImplicitUnicodeExtra()
        throws IOException {
        testFileRoundtrip(UTF_8, true, false);
    }

    @Test
    public void testUtf8FileRoundtripNoEFSImplicitUnicodeExtra()
        throws IOException {
        testFileRoundtrip(UTF_8, false, false);
    }

    @Test
    public void testCP437FileRoundtripImplicitUnicodeExtra()
        throws IOException {
        testFileRoundtrip(CP437, false, false);
    }

    @Test
    public void testASCIIFileRoundtripImplicitUnicodeExtra()
        throws IOException {
        testFileRoundtrip(US_ASCII, false, false);
    }

    @Test
    public void testZipFileReadsUnicodeFields() throws IOException {
        File file = File.createTempFile("unicode-test", ".zip");
        ZipFile zf = null;
        try {
            createTestFile(file, US_ASCII, false, true);
            zf = new ZipFile(file, US_ASCII, true);
            assertCanRead(zf, ASCII_TXT);
            assertCanRead(zf, EURO_FOR_DOLLAR_TXT);
            assertCanRead(zf, OIL_BARREL_TXT);
        } finally {
            ZipFile.closeQuietly(zf);
            if (file.exists()) {
                file.delete();
            }
        }
    }

    private static void testFileRoundtrip(String encoding, boolean withEFS,
                                          boolean withExplicitUnicodeExtra)
        throws IOException {

        File file = File.createTempFile(encoding + "-test", ".zip");
        try {
            createTestFile(file, encoding, withEFS, withExplicitUnicodeExtra);
            testFile(file, encoding);
        } finally {
            if (file.exists()) {
                file.delete();
            }
        }
    }

    private static void createTestFile(File file, String encoding,
                                       boolean withEFS,
                                       boolean withExplicitUnicodeExtra)
        throws IOException {

        ZipEncoding zipEncoding = ZipEncodingHelper.getZipEncoding(encoding);

        try (ZipOutputStream zos = new ZipOutputStream(file)) {
            zos.setEncoding(encoding);
            zos.setUseLanguageEncodingFlag(withEFS);
            zos.setCreateUnicodeExtraFields(withExplicitUnicodeExtra
                    ? ZipOutputStream.UnicodeExtraFieldPolicy.NEVER
                    : ZipOutputStream.UnicodeExtraFieldPolicy.ALWAYS);

            ZipEntry ze = new ZipEntry(OIL_BARREL_TXT);
            if (withExplicitUnicodeExtra
                    && !zipEncoding.canEncode(ze.getName())) {

                ByteBuffer en = zipEncoding.encode(ze.getName());

                ze.addExtraField(new UnicodePathExtraField(ze.getName(),
                        en.array(),
                        en.arrayOffset(),
                        en.limit()));
            }

            zos.putNextEntry(ze);
            zos.write("Hello, world!".getBytes(StandardCharsets.US_ASCII));
            zos.closeEntry();

            ze = new ZipEntry(EURO_FOR_DOLLAR_TXT);
            if (withExplicitUnicodeExtra
                    && !zipEncoding.canEncode(ze.getName())) {

                ByteBuffer en = zipEncoding.encode(ze.getName());

                ze.addExtraField(new UnicodePathExtraField(ze.getName(),
                        en.array(),
                        en.arrayOffset(),
                        en.limit()));
            }

            zos.putNextEntry(ze);
            zos.write("Give me your money!".getBytes(StandardCharsets.US_ASCII));
            zos.closeEntry();

            ze = new ZipEntry(ASCII_TXT);

            if (withExplicitUnicodeExtra
                    && !zipEncoding.canEncode(ze.getName())) {

                ByteBuffer en = zipEncoding.encode(ze.getName());

                ze.addExtraField(new UnicodePathExtraField(ze.getName(),
                        en.array(),
                        en.arrayOffset(),
                        en.limit()));
            }

            zos.putNextEntry(ze);
            zos.write("ascii".getBytes(StandardCharsets.US_ASCII));
            zos.closeEntry();
        }
    }

    private static void testFile(File file, String encoding)
        throws IOException {
        ZipFile zf = null;
        try {
            zf = new ZipFile(file, encoding, false);
            for (ZipEntry ze : Collections.list(zf.getEntries())) {
                if (ze.getName().endsWith("sser.txt")) {
                    assertUnicodeName(ze, OIL_BARREL_TXT, encoding);

                } else if (ze.getName().endsWith("_for_Dollar.txt")) {
                    assertUnicodeName(ze, EURO_FOR_DOLLAR_TXT, encoding);
                } else if (!ze.getName().equals(ASCII_TXT)) {
                    throw new AssertionError("Unrecognized ZIP entry with name ["
                                             + ze.getName() + "] found.");
                }
            }
        } finally {
            ZipFile.closeQuietly(zf);
        }
    }

    private static UnicodePathExtraField findUniCodePath(ZipEntry ze) {
        return (UnicodePathExtraField)
            ze.getExtraField(UnicodePathExtraField.UPATH_ID);
    }

    private static void assertUnicodeName(ZipEntry ze,
                                          String expectedName,
                                          String encoding)
        throws IOException {
        if (!expectedName.equals(ze.getName())) {
            UnicodePathExtraField ucpf = findUniCodePath(ze);
            assertNotNull(ucpf);

            ZipEncoding enc = ZipEncodingHelper.getZipEncoding(encoding);
            ByteBuffer ne = enc.encode(ze.getName());

            CRC32 crc = new CRC32();
            crc.update(ne.array(), ne.arrayOffset(), ne.limit());

            assertEquals(crc.getValue(), ucpf.getNameCRC32());
            assertEquals(expectedName, new String(ucpf.getUnicodeName(), StandardCharsets.UTF_8));
        }
    }

    private static void assertCanRead(ZipFile zf, String fileName) throws IOException {
        ZipEntry entry = zf.getEntry(fileName);
        assertNotNull("Entry " + fileName + " doesn't exist", entry);
        try (InputStream is = zf.getInputStream(entry)) {
            assertNotNull("InputStream is null", is);
            is.read();
        }
    }

}
