package api;

import junit.framework.*;

import java.util.*;

public class ArithmeticaCompatibilityTest extends TestCase {

    public ArithmeticaCompatibilityTest(String name) {

        super(name);

    }

    private static final class CountingSubclass extends Arithmetica {

        int countSumTwo;

        int countSumAll;

        int countSumRange;

        @Override

        public int sumAll(int... numbers) {

            countSumAll++;

            return super.sumAll(numbers);

        }

        @Override

        public int sumRange(int from, int to) {

            countSumRange++;

            return super.sumRange(from, to);

        }

        @Override

        public int sumTwo(int one, int second) {

            countSumTwo++;

            return super.sumTwo(one, second);

        }

    } // end of CountingSubclass

    private static final class CountingOldSubclass extends OldArithmetica1 {

        int countSumTwo;

        int countSumAll;

        int countSumRange;

        @Override

        public int sumAll(int... numbers) {

            countSumAll++;

            return super.sumAll(numbers);

        }

        @Override

        public int sumRange(int from, int to) {

            countSumRange++;

            return super.sumRange(from, to);

        }

        @Override

        public int sumTwo(int one, int second) {

            countSumTwo++;

            return super.sumTwo(one, second);

        }

    } // end of CountingSubclass

    public void testRandomCheck () throws Exception {

        long seed = System.currentTimeMillis();

        try {

            CountingSubclass now = new CountingSubclass();

            CountingOldSubclass old = new CountingOldSubclass();

            compare(now, old, seed);

            assertEquals("Verify amount of sumRange is the same", now.countSumRange, old.countSumRange);

            assertEquals("Verify amount of sumAll is the same", now.countSumAll, old.countSumAll);

            assertEquals("Verify amount of sumTwo is the same", now.countSumTwo, old.countSumTwo);

        } catch (AssertionFailedError ex) {

            IllegalStateException n = new IllegalStateException ("Seed: " + seed + "\n" + ex.getMessage ());

            n.initCause(ex);

            throw n;

        } catch (Exception ex) {

            IllegalStateException n = new IllegalStateException ("Seed: " + seed + "\n" + ex.getMessage ());

            n.initCause(ex);

            throw n;

        }

    }

    public void testSimulateOKRunOn1208120436947() throws Exception {

        CountingSubclass now = new CountingSubclass();

        CountingOldSubclass old = new CountingOldSubclass();

        compare(now, old, 1208120436947L);

        assertEquals("Verify amount of sumRange is the same", now.countSumRange, old.countSumRange);

        assertEquals("Verify amount of sumAll is the same", now.countSumAll, old.countSumAll);

        assertEquals("Verify amount of sumTwo is the same", now.countSumTwo, old.countSumTwo);

    }

    public void testSimulateFailureOn1208120628821() throws Exception {

        CountingSubclass now = new CountingSubclass();

        CountingOldSubclass old = new CountingOldSubclass();

        compare(now, old, 1208120628821L);

        assertEquals("Verify amount of sumRange is the same", now.countSumRange, old.countSumRange);

        assertEquals("Verify amount of sumAll is the same", now.countSumAll, old.countSumAll);

        assertEquals("Verify amount of sumTwo is the same", now.countSumTwo, old.countSumTwo);

    }

    private void compare (CountingSubclass now, CountingOldSubclass old, long seed) throws Exception {

        java.util.Random r = new java.util.Random (seed);

        for (int loop = 0; loop < r.nextInt(5); loop++) {

            int operation = r.nextInt(3);

            switch (operation) {

                case 0: { // sumTwo

                    int a1 = r.nextInt(100);

                    int a2 = r.nextInt(100);

                    int resNow = now.sumTwo(a1, a2);

                    int resOld = old.sumTwo(a1, a2);

                    assertEquals("Results of sumTwo are equal", resNow, resOld);

                    break;

                }

                case 1: { // sumArray

                    int[] arr = new int[r.nextInt(100)];

                    for (int i = 0; i < arr.length; i++) {

                        arr[i] = r.nextInt(100);

                    }

                    int resNow = now.sumAll(arr);

                    int resOld = old.sumAll(arr);

                    assertEquals("Results of sumArray are equal", resNow, resOld);

                    break;

                }

                case 2: { // sumRange

                    int a1 = r.nextInt(100);

                    int a2 = r.nextInt(100);

                    int resNow = now.sumRange(a1, a1 + a2);

                    int resOld = old.sumRange(a1, a1 + a2);

                    assertEquals("Results of sumRange are equal", resNow, resOld);

                    break;

                }

            }

        }

    }

    /** This is a copy of the implementation of Arithmetica from version 1.0 */

    static class OldArithmetica1 {

        public int sumTwo(int one, int second) {

            return one + second;

        }

        public int sumAll(int... numbers) {

            if (numbers.length == 0) {

                return 0;

            }

            int sum = numbers[0];

            for (int i = 1; i < numbers.length; i++) {

                sum = sumTwo(sum, numbers[i]);

            }

            return sum;

        }

        public int sumRange(int from, int to) {

            int len = to - from;

            int[] array = new int[len + 1];

            for (int i = 0; i <= len; i++) {

                array[i] = from + i;

            }

            return sumAll(array);

        }

    } // end of OldArithmetica1

}