package cse1030;

/**
 * A class that represents an integer value that is always between some
 * minimum and maximum value. A range has three properties: minimum,
 * maximum, and value. Range objects always ensure that the following class invariant
 * is true:
 * 
 * <p>
 * <code>minimum <= value <= maximum</code>
 * 
 * <p>
 * The mutator methods of the class are responsible for ensuring that the
 * above class invariant is always true. For example, if the minimum value of the
 * range is changed so that it is greater than the current value, then the
 * current value is also adjusted to maintain the class invariant. If the
 * minimum value is changed so that it is greater than the maximum value,
 * then both the maximum value and current value are also changed to maintain
 * the class invariant. 
 *  
 * @author CSE1030Z
 *
 */
public class Range {
  private int min;
  private int max;
  private int value;

  /**
   * Create a range with minimum value 0, maximum value 100, and initial value
   * 50.
   */
  public Range() {
    this(0, 100, 50);
  }

  /**
   * Create a range with the specified minimum and maximum values. The initial
   * value is set to half way between the minimum and maximum values (rounded
   * down to the nearest integer if <code>max - min</code> is odd).
   * 
   * @param min
   *          the minimum value of the range
   * @param max
   *          the maximum value of the range
   * @throws IllegalArgumentException
   *           if <code>min > max</code>
   */
  public Range(int min, int max) {
    this(min, max, (max + min) / 2);
  }

  /**
   * Create a range with the specified minimum, maximum, and initial values.
   * 
   * @param min
   *          the minimum value of the range
   * @param max
   *          the maximum value of the range
   * @param init
   *          the initial value of the range
   * @throws IllegalArgumentException
   *           if the constraint <code>min <= init <= max</code> is not
   *           satisfied
   */
  public Range(int min, int max, int init) {
    if (min > max || min > init || max < init) {
      throw new IllegalArgumentException("invalid range properties");
    }
    this.min = min;
    this.value = init;
    this.max = max;
  }

  /**
   * Returns the minimum value of the range
   * 
   * @return the minimum value of the range
   */
  public int getMinimum() {
    return this.min;
  }

  /**
   * Sets the minimum value of the range to <code>newMinimum</code>. The other
   * properties of the range may be changed to ensure that:
   * 
   * <p>
   * <code>minimum <= value <= maximum</code>
   * 
   * @param newMinimum
   *          the new minimum of the range
   */
  public void setMinimum(int newMinimum) {
    this.min = newMinimum;
    if (newMinimum > this.getMaximum()) {
      this.setMaximum(newMinimum);
    }
    if (newMinimum > this.getValue()) {
      this.setValue(newMinimum);
    }
  }

  /**
   * Returns the maximum value of the range
   * 
   * @return the maximum value of the range
   */
  public int getMaximum() {
    return this.max;
  }

  /**
   * Sets the maximum value of the range to <code>newMaximum</code>. The other
   * properties of the range may be changed to ensure that:
   * 
   * <p>
   * <code>minimum <= value <= maximum</code>
   * 
   * @param newMaximum
   *          the new maximum of the range
   */
  public void setMaximum(int newMaximum) {
    this.max = newMaximum;
    if (newMaximum < this.getMinimum()) {
      this.setMinimum(newMaximum);
    }
    if (newMaximum < this.getValue()) {
      this.setValue(newMaximum);
    }
  }

  /**
   * Return the current value of the range.
   * 
   * @return the value of the range
   */
  public int getValue() {
    return this.value;
  }

  /**
   * Set the current value of the range to <code>newValue</code> if
   * <code>newValue</code> satisfies the constraints of the range. Those
   * constraints are:
   * 
   * <p>
   * <code>minimum <= value <= maximum</code>
   * 
   * <p>
   * Otherwise, if <code>newValue < minimum</code> then the value is set to the
   * minimum value of the range, and if <code>newValue > maximum</code> then the
   * value is set to the maximum value of the range.
   * 
   * @param value
   *          the new value of the range
   */
  public void setValue(int newValue) {
    if (this.getMinimum() <= newValue && newValue <= this.getMaximum()) {
      this.value = newValue;
    } else if (newValue < this.getMinimum()) {
      this.value = this.getMinimum();
    } else {
      this.value = this.getMaximum();
    }
  }

}