package cse1030;

import static org.junit.Assert.*;

import org.junit.Test;
import java.util.Collections;
import java.util.List;
import java.util.ArrayList;

public class YahtzeeTest {
	
  private static final int TRIALS = 10;

  @Test
  public void testIsThreeOfAKind() {
    List<Die> dice = null;
    List<Die> copy = null;
    for (int i = 0; i < TRIALS; i++) {
      dice = maxNOfAKind(2);
      copy = new ArrayList<Die>(dice);
      assertFalse(toString(dice), Yahtzee.isThreeOfAKind(dice));
      assertEquals("list of dice has changed!", dice, copy);
    }
    for (int i = 0; i < TRIALS; i++) {
      dice = minNOfAKind(3);
      assertTrue(toString(dice), Yahtzee.isThreeOfAKind(dice));
    }
  }

  @Test
  public void testIsFourOfAKind() {
    List<Die> dice = null;
    List<Die> copy = null;
    for (int i = 0; i < TRIALS; i++) {
      dice = maxNOfAKind(3);
      copy = new ArrayList<Die>(dice);
      assertFalse(toString(dice), Yahtzee.isFourOfAKind(dice));
      assertEquals("list of dice has changed!", dice, copy);
    }
    for (int i = 0; i < TRIALS; i++) {
      dice = minNOfAKind(4);
      assertTrue(toString(dice), Yahtzee.isFourOfAKind(dice));
    }
  }

  @Test
  public void testIsFiveOfAKind() {
    List<Die> dice = null;
    List<Die> copy = null;
    for (int i = 0; i < TRIALS; i++) {
      dice = maxNOfAKind(4);
      copy = new ArrayList<Die>(dice);
      assertFalse(toString(dice), Yahtzee.isFiveOfAKind(dice));
      assertEquals("list of dice has changed!", dice, copy);
    }
    for (int i = 0; i < TRIALS; i++) {
      dice = minNOfAKind(5);
      assertTrue(toString(dice), Yahtzee.isFiveOfAKind(dice));
    }
  }

  @Test
  public void testIsFullHouse() {
    List<Die> dice = null;
    List<Die> copy = null;
    for (int i = 0; i < TRIALS; i++) {
      dice = maxNOfAKind(2);
      copy = new ArrayList<Die>(dice);
      assertFalse(toString(dice), Yahtzee.isFullHouse(dice));
      assertEquals("list of dice has changed!", dice, copy);
    }
    for (int i = 0; i < TRIALS; i++) {
      dice = fullHouse();
      assertTrue(toString(dice), Yahtzee.isFullHouse(dice));
    }
  }

  @Test
  public void testIsSmallStraight() {
    List<Die> dice = null;
    List<Die> copy = null;
    for (int i = 0; i < TRIALS; i++) {
      dice = notStraight();
      copy = new ArrayList<Die>(dice);
      assertFalse(toString(dice), Yahtzee.isSmallStraight(dice));
      assertEquals("list of dice has changed!", dice, copy);
    }
    for (int i = 0; i < TRIALS; i++) {
      dice = straight(4);
      assertTrue(toString(dice), Yahtzee.isSmallStraight(dice));
    }
  }

  @Test
  public void testIsLargeStraight() {
    List<Die> dice = null;
    List<Die> copy = null;
    for (int i = 0; i < TRIALS; i++) {
      dice = notStraight();
      copy = new ArrayList<Die>(dice);
      assertFalse(toString(dice), Yahtzee.isSmallStraight(dice));
      assertEquals("list of dice has changed!", dice, copy);
    }
    for (int i = 0; i < TRIALS; i++) {
      dice = straight(5);
      assertTrue(toString(dice), Yahtzee.isSmallStraight(dice));
    }
  }

  private static List<Die> minNOfAKind(int n) {
    Die repeat = new Die();
    List<Die> dice = new ArrayList<Die>(5);
    for (int i = 0; i < n; i++) {
      dice.add(new Die(repeat));
    }
    for (int i = n; i < 5; i++) {
      Die d = new Die();
      dice.add(d);
    }
    Collections.shuffle(dice);
    return dice;
  }

  private static List<Die> maxNOfAKind(int n) {
    final int N = n * 6;
    List<Die> dice = new ArrayList<Die>(N);
    for (int i = 0; i < n; i++) {
      for (int j = 1; j <= 6; j++) {
        Die d = new Die();
        d.setValue(j);
        dice.add(d);
      }
    }
    Collections.shuffle(dice);
    return dice.subList(0, 5);
  }
  
  private static List<Die> fullHouse() {
    Die x = new Die();
    Die y = new Die();
    List<Die> dice = new ArrayList<Die>(5);
    dice.add(new Die(x));
    dice.add(new Die(x));
    dice.add(new Die(y));
    dice.add(new Die(y));
    dice.add(new Die(y));
    Collections.shuffle(dice);
    return dice;
  }
  
  private static List<Die> straight(int length) {
    final int MIN = 6 - length + 1;
    Die start = new Die(MIN);
    List<Die> dice = new ArrayList<Die>(5);
    dice.add(start);
    for (int i = 1; i < length; i++) {
      dice.add(new Die(6, start.getValue() + i));
    }
    for (int i = length; i < 5; i++) {
      dice.add(new Die());
    }
    Collections.shuffle(dice);
    return dice;
  }
  
  private static List<Die> notStraight() {
    List<Die> dice = new ArrayList<Die>(5);
    int count = 0;
    while (count < 5) {
      Die d = new Die();
      if (d.getValue() != 3) {
        dice.add(d);
        count++;
      }
    }
    return dice;
  }

  private static String toString(List<Die> dice) {
    StringBuilder b = new StringBuilder();
    b.append('[');
    for (Die d : dice) {
      b.append(d.getValue());
      b.append(", ");
    }
    b.append(']');
    return b.toString();
  }
}