//
// Program name:  timesheets
//
// Author:  I.N. Late
//
// Purpose:  Compute hours worked from timesheets
//
// Input:
//	name of input file containing timesheet data -- each line
//		contains an employee SSN (string), and starting and
//		stopping times, in military time
//	name of output file
//	(names obtained from user)
// Output:
//	output file containing, for each line in the input file,
//	the employee's SSN, plus hours, minutes, and seconds worked
//
#include <iostream.h>
#include <fstream.h>		// has ifstream, ofstream
#include <iomanip.h>		// has setw()

const int MaxFileNameLength = 1000;	// maximum length of filename

// ******** function prototypes ********

// I think there's something missing here!  
//	-- G.H. Now

//
// function to read in a time
//
// precondition:
//	inStr has been successfully opened
// postcondition:
//	if it is possible to read from inStr a time, in the format 
//		HH:MM:SS, return value is true, and hh, mm, ss contain
//		HH, MM, and SS respectively
//	otherwise return value is false
//
bool readTime(ifstream& inStr, int& hh, int& mm, int& ss);

//
// function to read in an integer and check its value
//
// precondition:
//	inStr has been successfully opened
// postcondition:
//	if it is possible to read from inStr an integer, and the
//		integer is >= min and <= max, return value is true,
//		and result contains the integer
//	otherwise return value is false
//
bool readIntInRange(ifstream& inStr, int& result, const int min, const int max);

// ******** main program ********

int main()
{
	ifstream inStream;
	ofstream outStream;

	const int MAXNAMELENGTH = 100;
	char employeeSSN[MAXNAMELENGTH];

	int beginH, beginM, beginS;
	int endH, endM, endS;
	int resultH, resultM, resultS;

	int beginTime, endTime, secondsOfWork;

	// I think there's something missing here!  
	//	-- G.H. Now

	while (readName(inStream, employeeSSN, MAXNAMELENGTH)
		&& readTime(inStream, beginH, beginM, beginS)
		&& readTime(inStream, endH, endM, endS))
	{
		beginTime = timeToSeconds(beginH, beginM, beginS);
		endTime = timeToSeconds(endH, endM, endS);
		secondsOfWork = endTime - beginTime;
		secondsToTime(secondsOfWork, resultH, resultM, resultS);
		printResults(outStream, employeeSSN, 
			resultH, resultM, resultS);
	}

	// I think there's something missing here!  
	//	-- G.H. Now

	return 0;
}

// ******** function definitions ********

bool readTime(ifstream& inStr, int& hh, int& mm, int& ss)
{
	char tempC;

	if (!readIntInRange(inStr, hh, 0, 23))
		return false;
	else if (!(inStr >> tempC) || tempC != ':')
		return false;
	else if (!readIntInRange(inStr, mm, 0, 59))
		return false;
	else if (!(inStr >> tempC) || tempC != ':')
		return false;
	else if (!readIntInRange(inStr, ss, 0, 59))
		return false;
	else
		return true;
}

bool readIntInRange(ifstream& inStr, int& result, const int min, const int max)
{
	// ">> dec" is needed because some systems otherwise think
	// that an integer starting with 0 is octal
	return ((inStr >> dec >> result) && result >= min && result <= max);
}

// I think there's something missing here!  
//	-- G.H. Now