/*
    * Copyright (C) 2012, Robin Rosenberg 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.util.io;
  
  import static java.nio.charset.StandardCharsets.UTF_8;
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  
  import org.eclipse.jgit.diff.RawText;
  import org.junit.Assert;
  import org.junit.Test;
  
  public class AutoCRLFInputStreamTest {
  
  	@Test
  	public void test() throws IOException {
  		assertNoCrLf("", "");
  		assertNoCrLf("\r", "\r");
  		assertNoCrLf("\r\n", "\n");
  		assertNoCrLf("\r\n", "\r\n");
  		assertNoCrLf("\r\r", "\r\r");
  		assertNoCrLf("\n\r", "\n\r"); // Lone CR
  		assertNoCrLf("\r\n\r\r", "\r\n\r\r");
  		assertNoCrLf("\r\n\r\n", "\r\n\r\n");
  		assertNoCrLf("\n\r\n\r", "\n\r\n\r"); // Lone CR
  		assertNoCrLf("\0\n", "\0\n");
  	}
  
  	@Test
  	public void testBoundary() throws IOException {
  		int boundary = RawText.getBufferSize();
  		for (int i = boundary - 10; i < boundary + 10; i++) {
  			String s1 = Strings.repeat("a", i);
  			assertNoCrLf(s1, s1);
  			String s2 = Strings.repeat("\0", i);
  			assertNoCrLf(s2, s2);
  		}
  	}
  
  	private void assertNoCrLf(String string, String string2) throws IOException {
  		assertNoCrLfHelper(string, string2);
  		// \u00e5 = LATIN SMALL LETTER A WITH RING ABOVE
  		// the byte value is negative
  		assertNoCrLfHelper("\u00e5" + string, "\u00e5" + string2);
  		assertNoCrLfHelper("\u00e5" + string + "\u00e5", "\u00e5" + string2
  				+ "\u00e5");
  		assertNoCrLfHelper(string + "\u00e5", string2 + "\u00e5");
  	}
  
  	private void assertNoCrLfHelper(String expect, String input)
  			throws IOException {
  		byte[] inbytes = input.getBytes(UTF_8);
  		byte[] expectBytes = expect.getBytes(UTF_8);
  		for (int i = 0; i < 5; ++i) {
  			byte[] buf = new byte[i];
  			try (ByteArrayInputStream bis = new ByteArrayInputStream(inbytes);
  					InputStream in = new AutoCRLFInputStream(bis, true);
  					ByteArrayOutputStream out = new ByteArrayOutputStream()) {
  				if (i > 0) {
  					int n;
  					while ((n = in.read(buf)) >= 0) {
  						out.write(buf, 0, n);
  					}
  				} else {
  					int c;
  					while ((c = in.read()) != -1)
  						out.write(c);
  				}
  				out.flush();
  				byte[] actualBytes = out.toByteArray();
  				Assert.assertEquals("bufsize=" + i, encode(expectBytes),
  						encode(actualBytes));
  			}
  		}
  	}
  
  	String encode(byte[] in) {
  		StringBuilder str = new StringBuilder();
  		for (byte b : in) {
  			if (b < 32)
  				str.append(0xFF & b);
  			else {
  				str.append("'");
  				str.append((char) b);
  				str.append("'");
  			}
  			str.append(' ');
  		}
 		return str.toString();
 	}
 
 }