/*
 * 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.any23.encoding;

import org.apache.tika.detect.TextStatistics;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.Charset;

import static java.nio.charset.StandardCharsets.ISO_8859_1;
import static java.nio.charset.StandardCharsets.UTF_8;
import static org.junit.Assert.assertEquals;

/**
 * Test case for {@link TikaEncodingDetector}.
 *
 * @author Michele Mostarda ( michele.mostarda@gmail.com )
 * @author Davide Palmisano ( dpalmisano@gmail.com )
 *
 * @version $Id$
 */
public class TikaEncodingDetectorTest {

    private TikaEncodingDetector detector;

    @Before
    public void setUp() {
        detector = new TikaEncodingDetector();
    }

    @After
    public void tearDown() {
        detector = null;
    }

    @Test
    public void testISO8859HTML() throws IOException {
        assertEncoding("ISO-8859-1", "/microformats/xfn/encoding-iso-8859-1.html");
    }

    @Test
    public void testISO8859XHTML() throws IOException {
        assertEncoding("ISO-8859-1", "/microformats/xfn/encoding-iso-8859-1.xhtml");
    }

    @Test
    public void testUTF8AfterTitle() throws IOException {
        assertEncoding("UTF-8", "/microformats/xfn/encoding-utf-8-after-title.html");
    }

    @Test
    public void testUTF8HTML() throws IOException {
        assertEncoding("UTF-8", "/microformats/xfn/encoding-utf-8.html");
    }

    @Test
    public void testUTF8XHTML() throws IOException {
        assertEncoding("UTF-8", "/microformats/xfn/encoding-utf-8.xhtml");
    }

    @Test
    public void testEncodingHTML() throws IOException {
        assertEncoding("UTF-8", "/html/encoding-test.html");
    }

    @Test
    public void testXMLEncodingPattern() throws IOException {
        String[] strings = { "<?xml encoding=\"UTF-8\"?>", " \n<?xMl encoding   = 'utf-8'?>",
                "\n <?Xml enCoding=Utf8?>" };
        for (String s : strings) {
            Charset detected = EncodingUtils.xmlCharset(new TextStatistics(), s);
            assertEquals(detected, UTF_8);
        }
    }

    private static ByteArrayInputStream bytes(String string, Charset encoding) {
        return new ByteArrayInputStream(string.getBytes(encoding));
    }

    @Test
    public void testUtf8Simple() throws IOException {
        assertEquals("UTF-8", detector.guessEncoding(bytes("Hellö Wörld!", UTF_8)));
    }

    @Test
    public void testIso88591Simple() throws IOException {
        assertEquals("ISO-8859-1", detector.guessEncoding(bytes("Hellö Wörld!", ISO_8859_1)));
    }

    @Test
    public void testTikaIssue771() throws IOException {
        assertEquals("UTF-8", detector.guessEncoding(bytes("Hello, World!", UTF_8)));
    }

    @Test
    public void testTikaIssue868() throws IOException {
        assertEquals("UTF-8", detector.guessEncoding(bytes("Indanyl", UTF_8)));
    }

    @Test
    public void testTikaIssue2771() throws IOException {
        assertEquals("UTF-8", detector.guessEncoding(bytes("Name: Amanda\nJazz Band", UTF_8)));
    }

    private void assertEncoding(final String expected, final String resource) throws IOException {
        try (InputStream fis = getClass().getResourceAsStream(resource)) {
            String encoding = detector.guessEncoding(fis);
            assertEquals("Unexpected encoding", expected, encoding);
        }
    }

}
