/* The contents of this file are subject to the license and copyright terms
 * detailed in the license directory at the root of the source tree (also
 * available online at http://fedora-commons.org/license/).
 */
package fedora.server.journal.helpers;

import java.util.HashSet;
import java.util.Set;

import junit.framework.TestCase;

public class TestPasswordCipher
        extends TestCase {

    private static final String CIPHER_TYPE_1 = "1";

    private static final String KEY_1 = "Now is the time for all";

    private static final String KEY_2 = "X";

    private static final String KEY_3 = "@lk<>2lkj-\u1234***";

    private static final String[] KEYS = new String[] {KEY_1, KEY_2, KEY_3};

    private static final String TEXT_1 = "Silly boys!";

    private static final String TEXT_2 = "234!@#$@#$@%$^&*";

    private static final String TEXT_3 = "FRED\u6655";

    private static final String[] TEXTS = new String[] {TEXT_1, TEXT_2, TEXT_3};

    public TestPasswordCipher(String name) {
        super(name);
    }

    public void testUniqueArgumentsOnEncipher() {
        try {
            PasswordCipher.encipher(null, TEXT_1);
            fail("Expected a NullPointerException");
        } catch (NullPointerException e) {
            // expected the exception
        }

        String cipher1 = PasswordCipher.encipher(KEY_1, null);
        assertNull(cipher1);

        String cipher2 = PasswordCipher.encipher("", TEXT_1);
        assertEquals(TEXT_1, cipher2);

    }

    /**
     * If the cipher text is null, the result will be null. If no key is
     * provided, or no cipher type is provided, the clear text will be the same
     * as the cipher text.
     */
    public void testUniqueArgumentsOnDecipher() {
        String clear1 = PasswordCipher.decipher(KEY_1, null, CIPHER_TYPE_1);
        assertNull(clear1);

        String clear2 = PasswordCipher.decipher(null, TEXT_1, CIPHER_TYPE_1);
        assertEquals(TEXT_1, clear2);

        String clear3 = PasswordCipher.decipher("", TEXT_2, CIPHER_TYPE_1);
        assertEquals(TEXT_2, clear3);

        String clear4 = PasswordCipher.decipher(KEY_2, TEXT_1, null);
        assertEquals(TEXT_1, clear4);

        String clear5 = PasswordCipher.decipher(KEY_2, TEXT_2, "");
        assertEquals(TEXT_2, clear5);
    }

    /**
     * The cipherText should not be the same as the clear text (unless the key
     * is empty).
     */
    public void testCipherDoesSomething() {
        for (String element : KEYS) {
            for (String element2 : TEXTS) {
                String cipher = PasswordCipher.encipher(element, element2);
                assertFalse(element2.equals(cipher));
            }
        }
    }

    /**
     * If I don't supply the type of cipher, deciphering has no effect.
     */
    public void testNullCipherDoesNothing() {
        for (String element : KEYS) {
            for (String element2 : TEXTS) {
                String deciphered =
                        PasswordCipher.decipher(element, element2, null);
                assertEquals(element2, deciphered);
            }
        }
    }

    /**
     * If I encipher and then decipher with the same key, I should get my
     * original text back.
     */
    public void testCipherIsReversible() {
        for (String element : KEYS) {
            for (String element2 : TEXTS) {
                String cipher = PasswordCipher.encipher(element, element2);
                String clear =
                        PasswordCipher.decipher(element, cipher, CIPHER_TYPE_1);
                assertEquals(element2, clear);
            }
        }
    }

    /**
     * If I pick a bunch of keys and texts at random, the ciphers should not
     * come out the same.
     */
    public void testCipherIsWellDistributed() {
        Set<String> ciphers = new HashSet<String>();

        for (String element : KEYS) {
            for (String element2 : TEXTS) {
                String cipher = PasswordCipher.encipher(element, element2);
                assertTrue("Set of ciphers already contains '" + cipher + "'",
                           ciphers.add(cipher));
            }
        }
    }

}