import org.junit.*;
import org.junit.runner.RunWith;
import static org.junit.Assert.*;
import static org.junit.Assume.*;

import org.junit.experimental.theories.DataPoint;
import org.junit.experimental.theories.DataPoints;
import org.junit.experimental.theories.Theories;
import org.junit.experimental.theories.Theory;

import java.util.*;

@RunWith(Theories.class)
public class TriangleTheoryTest {

   private static boolean DEBUG_ENABLED = true;
   private static int testCount = 0;

   @DataPoints
   public static int[] ints = {-2, -1, 0, 1, 2, 3, 4, 5, 10000};

   @Theory
   public void testNegativeSides(int x, int y, int z){
      assumeTrue( !allPositive(x, y, z));
      Triangle triangle = new Triangle(x, y, z);
      assertEquals(triangle.isValid(), false); 
      debug("Negative triangle sides under test " + triangle);
   }

   @Theory
   public void testFailsTriangleInequality(int x, int y, int z){
      assumeTrue( allPositive(x, y, z));
      assumeTrue( !triangleInequality(x, y, z));
      Triangle triangle = new Triangle(x, y, z);
      assertEquals(triangle.isValid(), false); 
      debug("Invalid triangle inequality under test " + triangle);
   }

   @Theory
   public void testIsosceles(int x, int y, int z){
      assumeTrue(validTriangle(x, y, z));
      assumeTrue(x == y && y != z ||
                 y == z && z != x ||
                 z == x && x != y);
      Triangle triangle = new Triangle(x, y, z);
      assertEquals(triangle.isIsosceles(), true); 
      debug("Isosceles triangle under test " + triangle);
   }

   @Theory
   public void testScalene(int x, int y, int z){
      assumeTrue(validTriangle(x, y, z));
      assumeTrue(x != y && y != z && x != z);
      Triangle triangle = new Triangle(x, y, z);
      assertEquals(triangle.isScalene(), true); 
      debug("Scalane triangle under test " + triangle);
   }

   @Theory
   public void testEquilaterals(int x, int y, int z){
      assumeTrue(allPositive(x, y, z));
      assumeTrue(x == y && y == z);
      Triangle triangle = new Triangle(x, y, z);
      assertEquals(triangle.isEquilateral(), true); 
      debug("Equilateral triangle under test " + triangle);
   }

   private boolean allPositive(int x, int y, int z) {
      return x > 0 && y > 0 && z > 0;
   }

   private boolean triangleInequality(int x, int y, int z) {
      return x+y >z && y+z > x && z+x > y;
   }

   private boolean validTriangle(int x, int y, int z) {
      return x+y >z && y+z > x && z+x > y;
   }

   private static void debug(String s) {
      if (DEBUG_ENABLED) {
         System.out.println("Test " + ++testCount + ": " + s);
      }
   }
}