#ifndef MONEY_H				// avoid repeated expansion
#define MONEY_H

#include <iostream>

/** Represents a monetary amount in dollars and cents */
class Money {

 public:

  /** Construct a new money instance.
   *  Automatically normalizes so that cents is between -99 and 99 and so that
   *  signs of the dollar and cents values do not disagree.
   *  @param  dollars     value in dollars
   *  @param  cents       value in cents (sign is assumed to match that of dollars)
   */
  explicit Money(int dollars=0, int cents=0);


  /** Return the amount of dollars.
   *
   *  If overall value is negative, the returned amount will be appropriately negated.
   *
   *  @return  number of dollars (signed)
   */
  int getDollars() const;

  /** Return the amount of cents.
   *
   *  If overall value is negative, the returned amount will be appropriately negated.
   *
   *  @return  number of cents (signed)
   */
  int getCents() const;

  /** Checks if current value is negative.
   *  @return  true if negative, false otherwise
   */
  bool isNegative() const;

  /** Binary addition of monetary values.
   *  @param    other   monetary value as second operand
   *  @return   sum of monetary values
   */
  Money operator+(const Money& other) const;

  /** Mutating form of addition for monetary values.
   *  @param    other   monetary value as second operand
   */
  void operator+=(const Money& other);

  /** Binary subtraction of monetary values.
   *  @param    other   monetary value as second operand
   *  @return   difference of monetary values
   */
  Money operator-(const Money& other) const;

  /** Mutating form of subtraction for monetary values.
   *  @param    other   monetary value as second operand
   */
  void operator-=(const Money& other);

  /** Unary negation of monetary value.
   *  @return   negation of original value
   */
  Money operator-() const;

  /** Compares two monetary amounts
   *  @param    other   monetary value as second operand
   *  @return   true if first is stricty less than second
   */
  bool operator<(const Money& other) const;

  /** Compares two monetary amounts
   *  @param    other   monetary value as second operand
   *  @return   true if first is less than or equal to the second
   */
  bool operator<=(const Money& other) const;

  /** Compares two monetary amounts
   *  @param    other   monetary value as second operand
   *  @return   true if first is stricty greater than second
   */
  bool operator>(const Money& other) const;

  /** Compares two monetary amounts
   *  @param    other   monetary value as second operand
   *  @return   true if first is greater than or equal to the second
   */
  bool operator>=(const Money& other) const;

  /** Compares two monetary amounts
   *  @param    other   monetary value as second operand
   *  @return   true if two are equivalent
   */
  bool operator==(const Money& other) const;

  /** Compares two monetary amounts
   *  @param    other   monetary value as second operand
   *  @return   true if two are non-equivalent
   */
  bool operator!=(const Money& other) const;

  /** Multiply monetary amount by a constant.
   *  Rounds to nearest cent.
   *  @param   factor   multiplicative factor
   *  @return new monetary value
   */
  Money operator*(double factor) const;

 private:
  int dollars;
  int cents;
  void normalize();
};

/**
 * Output the value in from such as $5.35 for positive value or
 * -$5.35 for a negative value.
 * @param   os     the output stream
 * @param   value  monetary value to display
 */
std::ostream& operator<<(std::ostream& os, const Money& value);

/** Multiply monetary amount by a constant.
 *  @param   factor   multiplicative factor
 *  @param   m        monetary value
 *  @return  new monetary value
 *  Rounds to nearest cent.
 */
Money operator*(double factor, const Money& m);


#endif