package elte.java2_utikalauz5.math;

import java.math.*;

/**
BigDecimal használata.

@link.forrásfájl {@docRoot}/../data/math/src BigDec.java
@link.letöltés {@docRoot}/../data/math BigDec.jar
@since Java 2 Útikalauz programozóknak
*/
class BigDec{

    private static MathContext mc = new MathContext(2, RoundingMode.HALF_UP);

 static void round(String num, int scale, int roundingMode) {
    try {
	    System.out.println(new BigDecimal(num).setScale(scale, roundingMode));
	} catch (Exception e) {
	    System.out.println(e);
	}
 }

 public static void main(String[] args) {
	System.out.println(new BigDecimal(1.23));        // 1.229999999999999982236431605997495353221893310546875
	try {
        System.out.println(new BigDecimal(Double.MAX_VALUE * Double.MAX_VALUE));
	} catch (Exception e) {
	    System.out.println(e);                  // NumberFormatException
	}
	System.out.println(new BigDecimal("-123.456"));//-123.456
	System.out.println(new BigDecimal("123."));  // 123
	System.out.println(new BigDecimal(".123"));  // 0.123
	System.out.println(new BigDecimal(".0"));    // 0.0
	System.out.println(new BigDecimal("0."));    // 0
	try {
	    System.out.println(new BigDecimal(" 123.456"));
	} catch (Exception e) {
	    System.out.println(e);                  // NumberFormatException
	}
	try {
	    System.out.println(new BigDecimal("123.456 "));
	} catch (Exception e) {
	    System.out.println(e);                  // NumberFormatException
	}
	System.out.println(new BigDecimal("+123.456")); // 123.456
	try {
	    System.out.println(new BigDecimal("."));
	} catch (Exception e) {
	    System.out.println(e);                  // NumberFormatException
	}
	System.out.println(new BigDecimal(new BigInteger("123"), 2));                       // 1.23

  BigDecimal a = new BigDecimal("-123.45");
  BigDecimal b = new BigDecimal("123.45");
  System.out.println(a.negate().equals(b));   // true
  a = new BigDecimal("1.23");
  b = new BigDecimal("1.230");
	System.out.println(a.equals(b));           // false
	System.out.println(a.compareTo(b));        // 0 az, mint stringek egyenlőek

        a = new BigDecimal("1.25");
        b = new BigDecimal("0.25");

        /** lebeg\u0151pontos számítás - J2SE 5.0 */
        BigDecimal c = a.multiply(b, mc);
        System.out.println("Lebeg\u0151pontos számolás: "+c);

        /** pontos érték, majd skálázás - J2SE 2.0 */
        c = a.multiply(b);
        System.out.println("Pontos érték: "+c);
        c = c.setScale(2, BigDecimal.ROUND_HALF_UP);
        System.out.println("Skálázó faktor beállítása után: "+c);

          a = new BigDecimal("2");
          b = new BigDecimal("3");
        MathContext mc1 = new MathContext(7, RoundingMode.HALF_EVEN);
        System.out.println( a.divide(b, mc1) ); /** Az eredmény: 0.6666667*/
        MathContext mc2 = new MathContext(7, RoundingMode.DOWN);
        System.out.println( a.divide(b, mc2) );/** Az eredmény: 0.6666666*/

         a = new BigDecimal("10.00");
        System.out.println(a.divide(new BigDecimal("5"), BigDecimal.ROUND_UNNECESSARY));   // Az eredmény : 2.00
	try {
        System.out.println(a.divide(new BigDecimal("3"), BigDecimal.ROUND_UNNECESSARY));
	} catch (Exception e) {
	    System.out.println(e);                  // ArithmeticException
	}
        System.out.println(a.divide(new BigDecimal("3"), BigDecimal.ROUND_DOWN)); // Az eredmény : 3.33
        System.out.println(a.divide(new BigDecimal("3"), 10, BigDecimal.ROUND_DOWN)); // Az eredmény : 3.3333333333
        System.out.println(a.divide(new BigDecimal("3"), 10, BigDecimal.ROUND_CEILING));// Az eredmény : 3.3333333334

	  a = new BigDecimal("1.23");
	 System.out.println(a.setScale(3));               // 1.230
	 // Skálázó faktor csökkentése
	 round(".5", 0, BigDecimal.ROUND_CEILING);        // 1
	 round(".5", 0, BigDecimal.ROUND_DOWN);           // 0
	 round(".5", 0, BigDecimal.ROUND_FLOOR);          // 0
	 round(".5", 0, BigDecimal.ROUND_HALF_DOWN);      // 0
	 round(".5", 0, BigDecimal.ROUND_HALF_EVEN);      // 0
	 round(".5", 0, BigDecimal.ROUND_HALF_UP);        // 1
	 round(".4", 0, BigDecimal.ROUND_HALF_UP);        // 0
	 round(".4", 0, BigDecimal.ROUND_UP);             // 1
	 round(".5", 0, BigDecimal.ROUND_UNNECESSARY);  // ArithmeticException
	 round("1.0", 0, BigDecimal.ROUND_UNNECESSARY);   // 1
	 round("-.5", 0, BigDecimal.ROUND_CEILING);       // 0
	 round("-.5", 0, BigDecimal.ROUND_DOWN);          // 0
	 round("-.5", 0, BigDecimal.ROUND_FLOOR);         // -1
	 round("-.5", 0, BigDecimal.ROUND_HALF_DOWN);     // 0
	 round("-.5", 0, BigDecimal.ROUND_HALF_EVEN);     // 0
	 round("-.5", 0, BigDecimal.ROUND_HALF_UP);       // -1
	 round("-.4", 0, BigDecimal.ROUND_HALF_UP);       // 0
	 round("-.4", 0, BigDecimal.ROUND_UP);            // -1
	 round("-.5", 0, BigDecimal.ROUND_UNNECESSARY); // ArithmeticException
	 round("-1.0", 0, BigDecimal.ROUND_UNNECESSARY);  // -1

	a = new BigDecimal("1.00");
	System.out.println(a.scale());     // 2
	a = a.movePointLeft(1);
	System.out.println(a);             // 0.100
	System.out.println(a.scale());     // 3
	a = a.movePointLeft(-2);
	System.out.println(a);             // 10.0
	System.out.println(a.scale());     // 1
	a = new BigDecimal("1.0");
	System.out.println(a.scale());     // skála értéke 1
	a = a.movePointRight(2);
	System.out.println(a);             // 100
	System.out.println(a.scale());     // skála érétk 0
	a = a.movePointRight(-3);
	System.out.println(a);             // .100
	System.out.println(a.scale());     // skála értéke 3

 }
}