/*
 *  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.
 */

/**
 * @author Vladimir N. Molotkov
 */

package org.apache.harmony.security.tests.java.security.spec;

import java.math.BigInteger;
import java.security.spec.ECFieldF2m;
import java.util.Arrays;

import junit.framework.TestCase;

/**
 * Tests for <code>ECFieldF2m</code> class fields and methods.
 */
public class ECFieldF2mTest extends TestCase {

    /**
     * Support class for this test.
     * Encapsulates <code>ECFieldF2m</code> testing
     * domain parameters.
     */
    private static final class ECFieldF2mDomainParams {

        /**
         * <code>NPE</code> reference object of class NullPointerException.
         * NullPointerException must be thrown by <code>ECFieldF2m</code>
         * ctors in some circumstances
         */
        static final NullPointerException NPE = new NullPointerException();
        /**
         * <code>IArgE</code> reference object of class IllegalArgumentException.
         * IllegalArgumentException must be thrown by <code>ECFieldF2m</code>
         * ctors in some circumstances
         */
        static final IllegalArgumentException IArgE = new IllegalArgumentException();

        /**
         * The <code>m</code> parameter for <code>ECFieldF2m</code>
         * ctor for the current test.
         */
        final int m;
        /**
         * The <code>rp</code> parameter for <code>ECFieldF2m</code>
         * ctor for the current test.
         */
        final BigInteger rp;
        /**
         * The <code>ks</code> parameter for <code>ECFieldF2m</code>
         * ctor for the current test.
         */
        final int[] ks;


        /**
         * Exception expected with this parameters set or <code>null</code>
         * if no exception expected.
         */
        final Exception x;

        /**
         * Constructs ECFieldF2mDomainParams
         *
         * @param m
         * @param rp
         * @param ks
         * @param expectedException
         */
        ECFieldF2mDomainParams(final int m,
                final BigInteger rp,
                final int[] ks,
                final Exception expectedException) {
            this.m = m;
            this.rp = rp;
            this.ks = ks;
            this.x = expectedException;
        }
    }

    /**
     * Constructor for ECFieldF2mTest.
     *
     * @param name
     */
    public ECFieldF2mTest(String name) {
        super(name);
    }

    //
    // Tests
    //

    /**
     * Set of parameters used for <code>ECFieldF2m(int)</code>
     * constructor tests.
     */
    private final ECFieldF2mDomainParams[] intCtorTestParameters =
            new ECFieldF2mDomainParams[] {
                    // set 0: valid m
                    new ECFieldF2mDomainParams(1, null, null, null),
                    // set 1: valid m
                    new ECFieldF2mDomainParams(Integer.MAX_VALUE, null, null, null),
                    // set 2: invalid m
                    new ECFieldF2mDomainParams(0, null, null, ECFieldF2mDomainParams.IArgE),
                    // set 3: invalid m
                    new ECFieldF2mDomainParams(-1, null, null, ECFieldF2mDomainParams.IArgE)
            };

    /**
     * Tests for constructor <code>ECFieldF2m(int)</code><br>
     * <p/>
     * Assertion: constructs new <code>ECFieldF2m</code> object
     * using valid parameter m.
     * <p/>
     * Assertion: IllegalArgumentException if m is not positive.
     */
    public final void testECFieldF2mint() {
        for (int i = 0; i < intCtorTestParameters.length; i++) {
            ECFieldF2mDomainParams tp = intCtorTestParameters[i];
            try {
                // perform test
                new ECFieldF2m(tp.m);

                if (tp.x != null) {
                    // exception has been expected 
                    fail(getName() + ", set " + i +
                            " FAILED: expected exception has not been thrown");
                }
            } catch (Exception e) {
                if (tp.x == null || !e.getClass().isInstance(tp.x)) {
                    // exception: failure
                    // if it has not been expected
                    // or wrong one has been thrown
                    fail(getName() + ", set " + i +
                            " FAILED: unexpected " + e);
                }
            }
        }
    }

    /**
     * Set of parameters used for <code>ECFieldF2m(int, BigInteger)</code>
     * constructor tests.
     */
    private final ECFieldF2mDomainParams[] intIntArrayCtorTestParameters =
            new ECFieldF2mDomainParams[] {
                    // set 0: valid m and ks - trinomial basis params
                    new ECFieldF2mDomainParams(
                            1999,
                            null,
                            new int[] { 367 },
                            null),
                    // set 1: valid m and ks - pentanomial basis params
                    new ECFieldF2mDomainParams(
                            2000,
                            null,
                            new int[] { 981, 2, 1 },
                            null),
                    // set 2: valid m, invalid (null) ks
                    new ECFieldF2mDomainParams(
                            1963,
                            null,
                            null,
                            ECFieldF2mDomainParams.NPE),
                    // set 3: valid m, invalid ks - wrong length
                    new ECFieldF2mDomainParams(
                            1963,
                            null,
                            new int[] { 981, 2 },
                            ECFieldF2mDomainParams.IArgE),
                    // set 4: valid m, invalid ks - wrong length
                    new ECFieldF2mDomainParams(
                            1963,
                            null,
                            new int[] { 981, 124, 2, 1 },
                            ECFieldF2mDomainParams.IArgE),
                    // set 5: valid m, invalid ks - wrong value
                    new ECFieldF2mDomainParams(
                            1999,
                            null,
                            new int[] { 1999 },
                            ECFieldF2mDomainParams.IArgE),
                    // set 6: valid m, invalid ks - wrong value
                    new ECFieldF2mDomainParams(
                            1999,
                            null,
                            new int[] { 0 },
                            ECFieldF2mDomainParams.IArgE),
                    // set 7: valid m, invalid ks - wrong values
                    new ECFieldF2mDomainParams(
                            2000,
                            null,
                            new int[] { 2000, 2, 1 },
                            ECFieldF2mDomainParams.IArgE),
                    // set 8: valid m, invalid ks - wrong values
                    new ECFieldF2mDomainParams(
                            2000,
                            null,
                            new int[] { 981, 2, 0 },
                            ECFieldF2mDomainParams.IArgE),
                    // set 9: invalid m
                    new ECFieldF2mDomainParams(
                            -5,
                            null,
                            new int[] { 981, 2, 1 },
                            ECFieldF2mDomainParams.IArgE),
                    // set 10: valid m, invalid ks - wrong order
                    new ECFieldF2mDomainParams(
                            2000,
                            null,
                            new int[] { 981, 1, 2 },
                            ECFieldF2mDomainParams.IArgE),
                    // set 11: valid m, invalid ks - no content
                    new ECFieldF2mDomainParams(
                            2000,
                            null,
                            new int[3],
                            ECFieldF2mDomainParams.IArgE),
                    // set 12: valid m, invalid ks - length is 0
                    new ECFieldF2mDomainParams(
                            2000,
                            null,
                            new int[0],
                            ECFieldF2mDomainParams.IArgE),
            };

    /**
     * Tests for constructor <code>ECFieldF2m(int m, int[] ks)</code><br>
     * <p/>
     * Assertion: constructs new <code>ECFieldF2m</code> object
     * using valid parameters m and rp. ks represents trinomial basis.
     * <p/>
     * Assertion: constructs new <code>ECFieldF2m</code> object
     * using valid parameters m and ks. ks represents pentanomial basis.
     * <p/>
     * Assertion: IllegalArgumentException if m is not positive.
     * <p/>
     * Assertion: NullPointerException if ks is null.
     * <p/>
     * Assertion: IllegalArgumentException if ks is invalid.
     */
    public final void testECFieldF2mintintArray() {
        for (int i = 0; i < intIntArrayCtorTestParameters.length; i++) {
            ECFieldF2mDomainParams tp = intIntArrayCtorTestParameters[i];
            try {
                // perform test
                new ECFieldF2m(tp.m, tp.ks);

                if (tp.x != null) {
                    // exception has been expected 
                    fail(getName() + ", set " + i +
                            " FAILED: expected exception has not been thrown");
                }
            } catch (Exception e) {
                if (tp.x == null || !e.getClass().isInstance(tp.x)) {
                    // exception: failure
                    // if it has not been expected
                    // or wrong one has been thrown
                    fail(getName() + ", set " + i +
                            " FAILED: unexpected " + e);
                }
            }
        }
    }

    /**
     * Test #1 for <code>hashCode()</code> method.<br>
     * <p/>
     * Assertion: must return the same value if invoked
     * repeatedly on the same object.
     */
    public final void testHashCode01() {
        ECFieldF2m f = new ECFieldF2m(2000);
        int hc = f.hashCode();
        assertTrue(hc == f.hashCode() &&
                hc == f.hashCode() &&
                hc == f.hashCode() &&
                hc == f.hashCode() &&
                hc == f.hashCode() &&
                hc == f.hashCode() &&
                hc == f.hashCode() &&
                hc == f.hashCode());
    }

    /**
     * Test #2 for <code>hashCode()</code> method.<br>
     * <p/>
     * Assertion: must return the same value if invoked
     * repeatedly on the same object.
     */
    public final void testHashCode02() {
        ECFieldF2m f = new ECFieldF2m(2000, new int[] { 981, 2, 1 });
        int hc = f.hashCode();
        assertTrue(hc == f.hashCode() &&
                hc == f.hashCode() &&
                hc == f.hashCode() &&
                hc == f.hashCode() &&
                hc == f.hashCode() &&
                hc == f.hashCode() &&
                hc == f.hashCode() &&
                hc == f.hashCode());
    }

    /**
     * Test #3 for <code>hashCode()</code> method.<br>
     * <p/>
     * Assertion: must return the same value if invoked
     * on equal (according to the <code>equals(Object)</code> method) objects.
     */
    public final void testHashCode03() {
        assertTrue(new ECFieldF2m(111).hashCode() ==
                new ECFieldF2m(111).hashCode());
    }

    /**
     * Test #4 for <code>hashCode()</code> method.<br>
     * <p/>
     * Assertion: must return the same value if invoked
     * on equal (according to the <code>equals(Object)</code> method) objects.
     */
    public final void testHashCode04() {
        assertTrue(new ECFieldF2m(2000, new int[] { 981, 2, 1 }).hashCode() ==
                new ECFieldF2m(2000, new int[] { 981, 2, 1 }).hashCode());
    }

    /**
     * Test #5 for <code>hashCode()</code> method.<br>
     * <p/>
     * Assertion: must return the same value if invoked
     * on equal (according to the <code>equals(Object)</code> method) objects.
     */
    public final void testHashCode05() {
        assertTrue(new ECFieldF2m(2000, new int[] { 981, 2, 1 }).hashCode() ==
                new ECFieldF2m(2000, BigInteger.valueOf(0L).
                        setBit(0).setBit(1).setBit(2).
                        setBit(981).setBit(2000)).hashCode());
    }

    /**
     * Test #1 for <code>equals()</code> method.<br>
     * <p/>
     * Assertion: object equals to itself.
     */
    public final void testEqualsObject01() {
        ECFieldF2m obj = new ECFieldF2m(1999, new int[] { 367 });
        assertTrue(obj.equals(obj));
    }

    /**
     * Test #2 for <code>equals()</code> method.<br>
     * <p/>
     * Assertion: normal basis - objects equal if their m are equal.
     */
    public final void testEqualsObject02() {
        assertTrue(new ECFieldF2m(43).equals(new ECFieldF2m(43)));
    }

    /**
     * Test #3 for <code>equals()</code> method.<br>
     * <p/>
     * Assertion: trinomial basis - objects equal if their m, and rp
     * are mutually equal.
     */
    public final void testEqualsObject03() {
        assertTrue(new ECFieldF2m(1999, new int[] { 367 }).equals(
                new ECFieldF2m(1999, BigInteger.valueOf(0L).
                        setBit(0).setBit(367).setBit(1999))));
    }

    /**
     * Test #4 for <code>equals()</code> method.<br>
     * <p/>
     * Assertion: pentanomial basis - objects equal if their m, and rp
     * are mutually equal.
     */
    public final void testEqualsObject04() {
        ECFieldF2m f1 = new ECFieldF2m(2000, new int[] { 981, 2, 1 });
        ECFieldF2m f2 = new ECFieldF2m(2000, BigInteger.valueOf(0L).
                setBit(0).setBit(1).setBit(2).
                setBit(981).setBit(2000));
        assertTrue(f1.equals(f2) && f2.equals(f1));
    }

    /**
     * Test #5 for <code>equals()</code> method.<br>
     * <p/>
     * Assertion: objects equal if their m, and rp are mutually equal.
     */
    public final void testEqualsObject05() {
        ECFieldF2m f1 = new ECFieldF2m(2000);
        ECFieldF2m f2 = new ECFieldF2m(2000, BigInteger.valueOf(0L).
                setBit(0).setBit(1).setBit(2).
                setBit(981).setBit(2000));
        assertFalse(f1.equals(f2) || f2.equals(f1));
    }

    /**
     * Test #6 for <code>equals(Object obj)</code> method.<br>
     * <p/>
     * Assertion: returns false if obj is <code>null</code>
     */
    public final void testEqualsObject06() {
        assertFalse(new ECFieldF2m(2000).equals(null));
    }

    /**
     * Test #7 for <code>equals(Object obj)</code> method.<br>
     * <p/>
     * Assertion: returns false if obj is not instance of <code>ECFieldF2m</code>
     */
    public final void testEqualsObject07() {
        assertFalse(new ECFieldF2m(2000).equals(new Object()));
    }

    /**
     * Test for <code>getFieldSize()</code> method.<br>
     * <p/>
     * Assertion: returns m value for <code>ECFieldF2m</code>
     */
    public final void testGetFieldSize() {
        assertEquals(2000, new ECFieldF2m(2000).getFieldSize());
    }

    /**
     * Test for <code>getM()</code> method.<br>
     * <p/>
     * Assertion: returns m value for <code>ECFieldF2m</code>
     */
    public final void testGetM() {
        assertEquals(2000, new ECFieldF2m(2000).getM());
    }

    /**
     * Test #1 for <code>getMidTermsOfReductionPolynomial()</code> method.<br>
     * <p/>
     * Assertion: returns mid terms of reduction polynomial
     */
    public final void testGetMidTermsOfReductionPolynomial01() {
        int[] a = new int[] { 981, 2, 1 };
        int[] b = new ECFieldF2m(2000,
                BigInteger.valueOf(0L).setBit(0).setBit(1).
                        setBit(2).setBit(981).setBit(2000)).
                getMidTermsOfReductionPolynomial();
        assertTrue(Arrays.equals(a, b));
    }

    /**
     * Test #2 for <code>getMidTermsOfReductionPolynomial()</code> method.<br>
     * <p/>
     * Assertion: returns null for normal basis
     */
    public final void testGetMidTermsOfReductionPolynomial02() {
        assertNull(new ECFieldF2m(2000).getMidTermsOfReductionPolynomial());
    }

    /**
     * Test #3 for <code>getMidTermsOfReductionPolynomial()</code> method.<br>
     * <p/>
     * Assertion: returns mid terms of reduction polynomial
     */
    public final void testGetMidTermsOfReductionPolynomial03() {
        int[] a = new int[] { 367 };
        int[] b = new ECFieldF2m(1999, a).getMidTermsOfReductionPolynomial();
        assertTrue(Arrays.equals(a, b));
    }

    /**
     * Test #1 for <code>getReductionPolynomial()</code> method.<br>
     * <p/>
     * Assertion: returns reduction polynomial
     */
    public final void testGetReductionPolynomial01() {
        BigInteger rp = BigInteger.valueOf(0L).setBit(0).setBit(1).setBit(2).
                setBit(981).setBit(2000);
        assertTrue(new ECFieldF2m(2000, rp).getReductionPolynomial().equals(rp));
    }

    /**
     * Test #2 for <code>getReductionPolynomial()</code> method.<br>
     * <p/>
     * Assertion: returns null for normal basis
     */
    public final void testGetReductionPolynomial02() {
        assertNull(new ECFieldF2m(2000).getReductionPolynomial());
    }

    /**
     * Tests that object state is preserved against modifications
     * through array reference passed to the constructor.
     */
    public final void testIsStatePreserved01() {
        // reference array
        int[] a = new int[] { 367 };
        // reference array copy
        int[] aCopy = a.clone();
        // create obj using copy
        ECFieldF2m f = new ECFieldF2m(1999, aCopy);
        // modify copy
        aCopy[0] = 5;
        // compare reference with returned array
        assertTrue(Arrays.equals(a, f.getMidTermsOfReductionPolynomial()));
    }

    /**
     * Tests that object state is preserved against
     * modifications through array reference returned by
     * <code>getMidTermsOfReductionPolynomial()</code> method.
     */
    public final void testIsStatePreserved02() {
        // reference array
        int[] a = new int[] { 981, 2, 1 };
        // reference array copy
        int[] aCopy = a.clone();
        // create obj using copy
        ECFieldF2m f = new ECFieldF2m(2000, aCopy);
        // get array reference and modify returned array
        f.getMidTermsOfReductionPolynomial()[0] = 1532;
        // compare reference with returned for the second time array
        assertTrue(Arrays.equals(a, f.getMidTermsOfReductionPolynomial()));
    }

}