/*
 * Copyright (C) 2009, Google Inc.
 * Copyright (C) 2009, Johannes E. Schindelin <johannes.schindelin@gmx.de> and others
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0 which is available at
 * https://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

package org.eclipse.jgit.diff;

import static java.nio.charset.StandardCharsets.UTF_8;
import static org.junit.Assert.assertArrayEquals;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Arrays;

import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.util.RawParseUtils;
import org.junit.Test;

public class RawTextTest {
	@Test
	public void testEmpty() {
		final RawText r = new RawText(new byte[0]);
		assertEquals(0, r.size());
	}

	@Test
	public void testNul() {
		String input = "foo-a\nf\0o-b\n";
		byte[] data = Constants.encodeASCII(input);
		final RawText a = new RawText(data);
		assertArrayEquals(a.content, data);
		assertEquals(2, a.size());
		assertEquals("foo-a\n", a.getString(0, 1, false));
		assertEquals("f\0o-b\n", a.getString(1, 2, false));
		assertEquals("foo-a", a.getString(0, 1, true));
		assertEquals("f\0o-b", a.getString(1, 2, true));
	}

	@Test
	public void testCrLfTextYes() {
		assertTrue(RawText
				.isCrLfText(Constants.encodeASCII("line 1\r\nline 2\r\n")));
	}

	@Test
	public void testCrLfTextNo() {
		assertFalse(
				RawText.isCrLfText(Constants.encodeASCII("line 1\nline 2\n")));
	}

	@Test
	public void testCrLfTextBinary() {
		assertFalse(RawText
				.isCrLfText(Constants.encodeASCII("line 1\r\nline\0 2\r\n")));
	}

	@Test
	public void testCrLfTextMixed() {
		assertTrue(RawText
				.isCrLfText(Constants.encodeASCII("line 1\nline 2\r\n")));
	}

	@Test
	public void testCrLfTextCutShort() {
		assertFalse(
				RawText.isCrLfText(Constants.encodeASCII("line 1\nline 2\r")));
	}

	@Test
	public void testEquals() {
		final RawText a = new RawText(Constants.encodeASCII("foo-a\nfoo-b\n"));
		final RawText b = new RawText(Constants.encodeASCII("foo-b\nfoo-c\n"));
		RawTextComparator cmp = RawTextComparator.DEFAULT;

		assertEquals(2, a.size());
		assertEquals(2, b.size());

		// foo-a != foo-b
		assertFalse(cmp.equals(a, 0, b, 0));
		assertFalse(cmp.equals(b, 0, a, 0));

		// foo-b == foo-b
		assertTrue(cmp.equals(a, 1, b, 0));
		assertTrue(cmp.equals(b, 0, a, 1));
	}

	@Test
	public void testWriteLine1() throws IOException {
		final RawText a = new RawText(Constants.encodeASCII("foo-a\nfoo-b\n"));
		final ByteArrayOutputStream o = new ByteArrayOutputStream();
		a.writeLine(o, 0);
		final byte[] r = o.toByteArray();
		assertEquals("foo-a", RawParseUtils.decode(r));
	}

	@Test
	public void testWriteLine2() throws IOException {
		final RawText a = new RawText(Constants.encodeASCII("foo-a\nfoo-b"));
		final ByteArrayOutputStream o = new ByteArrayOutputStream();
		a.writeLine(o, 1);
		final byte[] r = o.toByteArray();
		assertEquals("foo-b", RawParseUtils.decode(r));
	}

	@Test
	public void testWriteLine3() throws IOException {
		final RawText a = new RawText(Constants.encodeASCII("a\n\nb\n"));
		final ByteArrayOutputStream o = new ByteArrayOutputStream();
		a.writeLine(o, 1);
		final byte[] r = o.toByteArray();
		assertEquals("", RawParseUtils.decode(r));
	}

	@Test
	public void testComparatorReduceCommonStartEnd() {
		final RawTextComparator c = RawTextComparator.DEFAULT;
		Edit e;

		e = c.reduceCommonStartEnd(t(""), t(""), new Edit(0, 0, 0, 0));
		assertEquals(new Edit(0, 0, 0, 0), e);

		e = c.reduceCommonStartEnd(t("a"), t("b"), new Edit(0, 1, 0, 1));
		assertEquals(new Edit(0, 1, 0, 1), e);

		e = c.reduceCommonStartEnd(t("a"), t("a"), new Edit(0, 1, 0, 1));
		assertEquals(new Edit(1, 1, 1, 1), e);

		e = c.reduceCommonStartEnd(t("axB"), t("axC"), new Edit(0, 3, 0, 3));
		assertEquals(new Edit(2, 3, 2, 3), e);

		e = c.reduceCommonStartEnd(t("Bxy"), t("Cxy"), new Edit(0, 3, 0, 3));
		assertEquals(new Edit(0, 1, 0, 1), e);

		e = c.reduceCommonStartEnd(t("bc"), t("Abc"), new Edit(0, 2, 0, 3));
		assertEquals(new Edit(0, 0, 0, 1), e);

		e = new Edit(0, 5, 0, 5);
		e = c.reduceCommonStartEnd(t("abQxy"), t("abRxy"), e);
		assertEquals(new Edit(2, 3, 2, 3), e);

		RawText a = new RawText("p\na b\nQ\nc d\n".getBytes(UTF_8));
		RawText b = new RawText("p\na  b \nR\n c  d \n".getBytes(UTF_8));
		e = new Edit(0, 4, 0, 4);
		e = RawTextComparator.WS_IGNORE_ALL.reduceCommonStartEnd(a, b, e);
		assertEquals(new Edit(2, 3, 2, 3), e);
	}

	@Test
	public void testComparatorReduceCommonStartEnd_EmptyLine() {
		RawText a;
		RawText b;
		Edit e;

		a = new RawText("R\n y\n".getBytes(UTF_8));
		b = new RawText("S\n\n y\n".getBytes(UTF_8));
		e = new Edit(0, 2, 0, 3);
		e = RawTextComparator.DEFAULT.reduceCommonStartEnd(a, b, e);
		assertEquals(new Edit(0, 1, 0, 2), e);

		a = new RawText("S\n\n y\n".getBytes(UTF_8));
		b = new RawText("R\n y\n".getBytes(UTF_8));
		e = new Edit(0, 3, 0, 2);
		e = RawTextComparator.DEFAULT.reduceCommonStartEnd(a, b, e);
		assertEquals(new Edit(0, 2, 0, 1), e);
	}

	@Test
	public void testComparatorReduceCommonStartButLastLineNoEol() {
		RawText a;
		RawText b;
		Edit e;
		a = new RawText("start".getBytes(UTF_8));
		b = new RawText("start of line".getBytes(UTF_8));
		e = new Edit(0, 1, 0, 1);
		e = RawTextComparator.DEFAULT.reduceCommonStartEnd(a, b, e);
		assertEquals(new Edit(0, 1, 0, 1), e);
	}

	@Test
	public void testComparatorReduceCommonStartButLastLineNoEol_2() {
		RawText a;
		RawText b;
		Edit e;
		a = new RawText("start".getBytes(UTF_8));
		b = new RawText("start of\nlastline".getBytes(UTF_8));
		e = new Edit(0, 1, 0, 2);
		e = RawTextComparator.DEFAULT.reduceCommonStartEnd(a, b, e);
		assertEquals(new Edit(0, 1, 0, 2), e);
	}

	@Test
	public void testLineDelimiter() throws Exception {
		RawText rt = new RawText(Constants.encodeASCII("foo\n"));
		assertEquals("\n", rt.getLineDelimiter());
		assertFalse(rt.isMissingNewlineAtEnd());
		rt = new RawText(Constants.encodeASCII("foo\r\n"));
		assertEquals("\r\n", rt.getLineDelimiter());
		assertFalse(rt.isMissingNewlineAtEnd());

		rt = new RawText(Constants.encodeASCII("foo\nbar"));
		assertEquals("\n", rt.getLineDelimiter());
		assertTrue(rt.isMissingNewlineAtEnd());
		rt = new RawText(Constants.encodeASCII("foo\r\nbar"));
		assertEquals("\r\n", rt.getLineDelimiter());
		assertTrue(rt.isMissingNewlineAtEnd());

		rt = new RawText(Constants.encodeASCII("foo\nbar\r\n"));
		assertEquals("\n", rt.getLineDelimiter());
		assertFalse(rt.isMissingNewlineAtEnd());
		rt = new RawText(Constants.encodeASCII("foo\r\nbar\n"));
		assertEquals("\r\n", rt.getLineDelimiter());
		assertFalse(rt.isMissingNewlineAtEnd());

		rt = new RawText(Constants.encodeASCII("foo"));
		assertNull(rt.getLineDelimiter());
		assertTrue(rt.isMissingNewlineAtEnd());

		rt = new RawText(Constants.encodeASCII(""));
		assertNull(rt.getLineDelimiter());
		assertTrue(rt.isMissingNewlineAtEnd());

		rt = new RawText(Constants.encodeASCII("\n"));
		assertEquals("\n", rt.getLineDelimiter());
		assertFalse(rt.isMissingNewlineAtEnd());

		rt = new RawText(Constants.encodeASCII("\r\n"));
		assertEquals("\r\n", rt.getLineDelimiter());
		assertFalse(rt.isMissingNewlineAtEnd());
	}

	@Test
	public void testLineDelimiter2() throws Exception {
		RawText rt = new RawText(Constants.encodeASCII("\nfoo"));
		assertEquals("\n", rt.getLineDelimiter());
		assertTrue(rt.isMissingNewlineAtEnd());
	}

	@Test
	public void testCrAtLimit() throws Exception {
		int limit = RawText.getBufferSize();
		byte[] data = new byte[RawText.getBufferSize() + 2];
		data[0] = 'A';
		for (int i = 1; i < limit - 1; i++) {
			if (i % 7 == 0) {
				data[i] = '\n';
			} else {
				data[i] = (byte) ('A' + i % 7);
			}
		}
		data[limit - 1] = '\r';
		data[limit] = '\n';
		data[limit + 1] = 'A';
		assertTrue(RawText.isBinary(data, limit, true));
		assertFalse(RawText.isBinary(data, limit, false));
		assertFalse(RawText.isBinary(data, data.length, true));
		byte[] buf = Arrays.copyOf(data, limit);
		try (ByteArrayInputStream in = new ByteArrayInputStream(buf)) {
			assertTrue(RawText.isBinary(in));
		}
		byte[] buf2 = Arrays.copyOf(data, limit + 1);
		try (ByteArrayInputStream in = new ByteArrayInputStream(buf2)) {
			assertFalse(RawText.isBinary(in));
		}
		byte[] buf3 = Arrays.copyOf(data, limit + 2);
		try (ByteArrayInputStream in = new ByteArrayInputStream(buf3)) {
			assertFalse(RawText.isBinary(in));
		}
	}

	private static RawText t(String text) {
		StringBuilder r = new StringBuilder();
		for (int i = 0; i < text.length(); i++) {
			r.append(text.charAt(i));
			r.append('\n');
		}
		return new RawText(r.toString().getBytes(UTF_8));
	}
}