package helpers;

import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import static org.hamcrest.Matchers.is;
import static org.junit.Assert.assertThat;
import org.junit.Test;

public class TestScryptHelper {

	private static final Charset utf8 = StandardCharsets.UTF_8;

	@Test
	public void testStandardVector1() throws Exception {

		/*
			Check against the test vectors described at:
				https://tools.ietf.org/html/rfc7914#section-12
		 */
		byte[] standardVector = new byte[]{(byte) 0x70, (byte) 0x23, (byte) 0xbd,
			(byte) 0xcb, (byte) 0x3a, (byte) 0xfd, (byte) 0x73, (byte) 0x48,
			(byte) 0x46, (byte) 0x1c, (byte) 0x06, (byte) 0xcd, (byte) 0x81,
			(byte) 0xfd, (byte) 0x38, (byte) 0xeb, (byte) 0xfd, (byte) 0xa8,
			(byte) 0xfb, (byte) 0xba, (byte) 0x90, (byte) 0x4f, (byte) 0x8e,
			(byte) 0x3e, (byte) 0xa9, (byte) 0xb5, (byte) 0x43, (byte) 0xf6,
			(byte) 0x54, (byte) 0x5d, (byte) 0xa1, (byte) 0xf2, (byte) 0xd5,
			(byte) 0x43, (byte) 0x29, (byte) 0x55, (byte) 0x61, (byte) 0x3f,
			(byte) 0x0f, (byte) 0xcf, (byte) 0x62, (byte) 0xd4, (byte) 0x97,
			(byte) 0x05, (byte) 0x24, (byte) 0x2a, (byte) 0x9a, (byte) 0xf9,
			(byte) 0xe6, (byte) 0x1e, (byte) 0x85, (byte) 0xdc, (byte) 0x0d,
			(byte) 0x65, (byte) 0x1e, (byte) 0x40, (byte) 0xdf, (byte) 0xcf,
			(byte) 0x01, (byte) 0x7b, (byte) 0x45, (byte) 0x57, (byte) 0x58,
			(byte) 0x87};

		String password = "pleaseletmein";
		byte[] salt = "SodiumChloride".getBytes(utf8);

		byte[] hash = ScryptHelper.hash(password, salt, 16384, 8, 1, 64);

		assertThat(hash, is(standardVector));
	}

	@Test
	public void testStandardVector2() throws Exception {

		/*
			Check against the test vectors described at:
				https://tools.ietf.org/html/rfc7914#section-12
		 */
		byte[] standardVector = new byte[]{(byte) 0xfd, (byte) 0xba, (byte) 0xbe,
			(byte) 0x1c, (byte) 0x9d, (byte) 0x34, (byte) 0x72, (byte) 0x00,
			(byte) 0x78, (byte) 0x56, (byte) 0xe7, (byte) 0x19, (byte) 0x0d,
			(byte) 0x01, (byte) 0xe9, (byte) 0xfe, (byte) 0x7c, (byte) 0x6a,
			(byte) 0xd7, (byte) 0xcb, (byte) 0xc8, (byte) 0x23, (byte) 0x78,
			(byte) 0x30, (byte) 0xe7, (byte) 0x73, (byte) 0x76, (byte) 0x63,
			(byte) 0x4b, (byte) 0x37, (byte) 0x31, (byte) 0x62, (byte) 0x2e,
			(byte) 0xaf, (byte) 0x30, (byte) 0xd9, (byte) 0x2e, (byte) 0x22,
			(byte) 0xa3, (byte) 0x88, (byte) 0x6f, (byte) 0xf1, (byte) 0x09,
			(byte) 0x27, (byte) 0x9d, (byte) 0x98, (byte) 0x30, (byte) 0xda,
			(byte) 0xc7, (byte) 0x27, (byte) 0xaf, (byte) 0xb9, (byte) 0x4a,
			(byte) 0x83, (byte) 0xee, (byte) 0x6d, (byte) 0x83, (byte) 0x60,
			(byte) 0xcb, (byte) 0xdf, (byte) 0xa2, (byte) 0xcc, (byte) 0x06,
			(byte) 0x40};

		String password = "password";
		byte[] salt = "NaCl".getBytes(utf8);

		byte[] hash = ScryptHelper.hash(password, salt, 1024, 8, 16, 64);

		assertThat(hash, is(standardVector));
	}

	@Test
	public void testUTF8Password() throws Exception {
		String password = "\uD83D\uDCA9\uD83D\uDCA9\uD83D\uDCA9\uD83D\uDCA9\uD83D\uDCA9";
		String hash = ScryptHelper.hash(password).toString();
		boolean result = ScryptHelper.check(hash, password);
		assertThat(result, is(true));
	}

	@Test
	public void testSimplePassword() throws Exception {
		String password = "testing123";
		String hash = ScryptHelper.hash(password).toString();
		boolean result = ScryptHelper.check(hash, password);
		assertThat(result, is(true));
	}

	@Test
	public void testLongPassword() throws Exception {
		String password = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
		String hash = ScryptHelper.hash(password).toString();
		boolean result = ScryptHelper.check(hash, password);
		assertThat(result, is(true));
	}

	@Test
	public void testEmptyPassword() throws Exception {
		String password = "";
		String hash = ScryptHelper.hash(password).toString();
		boolean result = ScryptHelper.check(hash, password);
		assertThat(result, is(true));
	}

	@Test
	public void testBadPassword() throws Exception {
		String password = "testing123";
		String bad = "testing321";
		String hash = ScryptHelper.hash(password).toString();
		boolean result = ScryptHelper.check(hash, bad);
		assertThat(result, is(false));
	}

	@Test
	public void testCharBufferPassword() throws Exception {
		CharBuffer password = CharBuffer.wrap("testing123");
		String hash = ScryptHelper.hash(password).toString();
		boolean result = ScryptHelper.check(hash, password);
		assertThat(result, is(true));
	}

	@Test(expected = Exception.class)
	public void testMalformedBase64() {
		String badB64 = "$2097160$!!!$!!!$"; // Invalid Base64 characters
		ScryptHelper.check(badB64, "password");
	}

	@Test(expected = IllegalArgumentException.class)
	public void testMissingParts() {
		String missingParts = "$2097160$salt$"; // Missing the hash part
		ScryptHelper.check(missingParts, "password");
	}

	@Test
	public void testHashTiming() throws Exception {
		final int REPS = 100;
		long startTime = System.currentTimeMillis();
		for (int i = 0; i < REPS; i++) {
			ScryptHelper.hash("wibble" + i);
		}
		long endTime = System.currentTimeMillis();
		System.out.println("Mean time per hash(): " + (endTime - startTime) / (float) REPS + " ms");
	}

	@Test
	public void testCheckTiming() throws Exception {
		final int REPS = 100;
		CharBuffer hash = ScryptHelper.hash("wibble42");
		long startTime = System.currentTimeMillis();
		for (int i = 0; i < REPS; i++) {
			ScryptHelper.check(hash, "wibble" + i);
		}
		long endTime = System.currentTimeMillis();
		System.out.println("Mean time per check(): " + (endTime - startTime) / (float) REPS + " ms");
	}

}