package cse1030;

/**
 * A simple phone number class that illustrates argument validation, constructor
 * chaining, equals, hashCode, and Comparable
 * 
 * @author CSE1030
 * 
 */
public final class PhoneNumber implements Comparable<PhoneNumber> {
  private final short areaCode;
  private final short exchangeCode;
  private final short stationCode;

  public PhoneNumber(int areaCode, int exchangeCode, int stationCode) {
    rangeCheck(areaCode, 999, "area code");
    rangeCheck(exchangeCode, 999, "exchange code");
    rangeCheck(stationCode, 9999, "station code");

    this.areaCode = (short) areaCode;
    this.exchangeCode = (short) exchangeCode;
    this.stationCode = (short) stationCode;
  }

  public PhoneNumber(PhoneNumber n) {
    this(n.getAreaCode(), n.getExchangeCode(), n.getStationCode());
  }

  private static void rangeCheck(int num, int max, String name) {
    if (num < 0 || num > max) {
      throw new IllegalArgumentException(name + " : " + num);
    }
  }

  public short getAreaCode() {
    return this.areaCode;
  }

  public short getExchangeCode() {
    return this.exchangeCode;
  }

  public short getStationCode() {
    return this.stationCode;
  }

  @Override
  public String toString() {
    return String.format("(%1$03d) %2$03d-%3$04d", this.areaCode,
        this.exchangeCode, this.stationCode);
  }

  @Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + areaCode;
    result = prime * result + exchangeCode;
    result = prime * result + stationCode;
    return result;
  }

  @Override
  public boolean equals(Object obj) {
    if (this == obj)
      return true;
    if (obj == null)
      return false;
    if (getClass() != obj.getClass())
      return false;
    PhoneNumber other = (PhoneNumber) obj;
    if (areaCode != other.areaCode)
      return false;
    if (exchangeCode != other.exchangeCode)
      return false;
    if (stationCode != other.stationCode)
      return false;
    return true;
  }

  @Override
  public int compareTo(PhoneNumber other) {
    int result = this.getAreaCode() - other.getAreaCode();
    if (result == 0) {
      // area codes are the same; compare exchange codes
      result = this.getExchangeCode() - other.getExchangeCode();
      if (result == 0) {
        // area and exchange codes are the same; compare station codes
        result = this.getStationCode() - other.getStationCode();
      }
    }
    return 0;
  }

  public static void main(String[] args) {
    PhoneNumber cse = new PhoneNumber(416, 736, 5053);
    System.out.println(cse == cse); // true

    PhoneNumber cseToo = cse;
    System.out.println(cseToo == cse); // true

    PhoneNumber cseAlso = new PhoneNumber(416, 736, 5053);
    System.out.println(cseAlso == cse);
  }

}