#ifndef TIME_H
#define TIME_H

#include <string>
#include <iostream>
#include <utility>

/**
 * An exception that is thrown by the Time class for invalid formats
 */
class __BadTimeException
{
	public:
		const std::string time; /** The string that failed to be parsed */
		
		/**
		 * __BadTimeException class constructor
		 * @param s The string that failed to be parsed
		 */
		__BadTimeException(const std::string& s);
};

/**
 * Time class that prints as hh:mm, can read in the same format and supports addition and subtraction of minutes. The time is represented as 24 hour time and any addition/subtraction is modulo 24:00.
 * @author Enoch Lau
 */
class Time
{
		int minutes; /** The time in minutes, from the begnning of the day */
		const static int MINUTES_IN_HOUR = 60; /** The number of minutes in an hour */
		const static int MINUTES_IN_DAY = 1440; /** The number of minutes in a day, 60 * 24 */
		
		/**
		 * Parse a time
		 * @param time The time in [hours]:[minutes] format, each of [hours] and [minutes] must be an integer (positive or negative)
		 * @throw Time::BadTimeException if the format could not be parsed
		 */
		void parse_time(const std::string& time);
		
	public:
		
		typedef __BadTimeException BadTimeException; /** An exception that is thrown by the Time class for invalid formats */
		
		/**
		 * Time class constructor
		 * @param m The time in minutes, from the begnning of the day
		 */
		Time(int m);
		
		/**
		 * Time class constructor
		 * @param h The number of whole hours to be included in the time
		 * @param m The number of whole minutes to be included in the time
		 */
		Time(int h, int m);
		
		/**
		 * Time class constructor
		 * @param time The time in [hours]:[minutes] format, each of [hours] and [minutes] must be an integer (positive or negative)
		 * @throw Time::BadTimeException if the format could not be parsed
		 */
		Time(const std::string& time);
		
		/**
		 * Gets the time in hh:mm format
		 * @return A pair, the first element being hours and the second element being minutes
		 */
		std::pair<int, int> get_time() const;
		
		/**
		 * Sets the time in hours and minutes
		 * @param h The number of whole hours to be included in the time
		 * @param m The number of whole minutes to be included in the time
		 */
		void set_time(int h, int m);
		
		/**
		 * Gets the number of minutes from the beginning of the day
		 * @return The number of minutes from the beginning of the day
		 */
		int get_total_minutes() const;
		
		/**
		 * Sets the minutes from the beginning of the day
		 * @param m The number of minutes from the beginning of the day
		 */
		void set_total_minutes(int m);
		
		/**
		 * Adds a Time to another Time
		 * @param t The right-hand operand
		 * @return A Time with the combined number of minutes of the two Time objects, modulo 24 hours
		 */
		Time operator+(const Time& t) const;
		
		/**
		 * Subtracts a Time from another Time
		 * @param t The right-hand operand
		 * @return A Time with the difference of the number of minutes of the two Time objects, modulo 24 hours
		 */
		Time operator-(const Time& t) const;
		
		/**
		 * Adds a Time to this Time
		 * @param t The right-hand operand
		 * @return The left-hand operand
		 */
		Time& operator+=(const Time& t);
		
		/**
		 * Subtracts a Time from this Time
		 * @param t The right-hand operand
		 * @return The left-hand operand
		 */
		Time& operator-=(const Time& t);
		
		/**
		 * Converts the Time to a string in hh:mm form
		 * @return The Time in hh:mm form
		 */
		std::string to_string() const;
		
		/**
		 * Compares two Time objects to see if they represent the same time
		 */
		bool operator==(const Time& other) const;
};

/**
 * Prints a Time to an output stream
 * @param out The output stream
 * @param t The Time to print
 */
std::ostream& operator<<(std::ostream& out, const Time& t);

/**
 * Sets a Time by reading in a string from an input stream and attempting to parse it
 * @param in The input stream
 * @param t The Time where the time will be stored
 * @throw Time::BadTimeException if the format could not be parsed
 */
std::istream& operator>>(std::istream& in, Time& t);

#endif