/* Assignment 8:  Pay for Music System */
/* Author:  Jennifer G. Lucas  jglucas02@yahoo.com */
/* Date:  03/22/01 */
/* Writing Functions (and previous material) */


#include <stdio.h>

/* function (header) to get valid data from user */

/* set parameters */
double GetValid(double min, double max){
	
	/* declare variables */
	double number;
	
	/* get info from user */
	printf("Please Enter A Number Between %4.2f and %4.2f:", min, max);
	scanf("%lf", &number);

	/* make sure user enters a correct number */
	while ((number < min) || (number > max)){
		printf("Please Enter A Number Between %4.2f and %4.2f:", min, max);
		scanf("%lf", &number);
	}
	
	/* return the number */
	return number;

}

/* function (header) to calculate the cost for current month */

/* set parameters */
double MonthlyCost(double downloads, double minutes){

	/* declare variables */
	const double baseCost = 10;
	const double minCost = 0.01;
	double cost;

	/* calculate the monthly cost if downloads are greater than or equal to five */
	if (downloads >= 5){
		
		cost = 15 + 2*(downloads - 5) + baseCost + (minCost * minutes);
	}
	
	/* calculate monthly cost if downloads are less than five */
	else {
		
		cost = (downloads * 3) + baseCost + (minCost * minutes);
	}

	/* return the cost */
	return cost;

}

int main (){

	/* declaration of variables */
	int count;
	double averageCost;
	double total;
	int numberCust;
	double songs;
	double connectMins;
	double totalSongs;
	double totalMins;
	double totalCost;
	double songAvg;
	double minAvg;
	double costAvg;
	double lastAvg;



	/* display Welcome Greeting */
	printf("Welcome to the Pay For Music System.\n");

	/* get the number of people to be processed */
	printf("How many people will be logged in this batch?");
	scanf("%d", &numberCust);

	/* initialization of totals */
	totalSongs = 0;
	totalMins = 0;
	totalCost = 0;

	/* get valid downloads and valid minutes from each person */
	for (count = 1; count <= numberCust; count++){

		/* display persons in order */
		printf("\nPerson	%d", count);

		/* get valid number of downloads */
		printf("\nNumber of Downloads This Month ");
		songs = GetValid(0, 1000);
		/* calculate total number of songs */
		totalSongs = totalSongs + songs;

		/* get valid number of minutes */
		printf("\nNumber of Minutes Connected ");
		connectMins = GetValid(0, 40000);
		/* calculate total number of minutes */
		totalMins = totalMins + connectMins;

		/* display the monthly cost */
		total = MonthlyCost(songs, connectMins);
		printf("\nCost: %5.2f", total);
		/* calculate total cost */
		totalCost = totalCost + total;

		/* display average cost per song */
		averageCost = total/songs;
		printf("\nAve Cost Per Song:	%5.2f", averageCost);

		/* end of "for" loop */

	}
	
	/* calculate final averages for songs, minutes, monthly cost, and cost per song */
	songAvg = totalSongs/numberCust;
	minAvg = totalMins/numberCust;
	costAvg = totalCost/numberCust;
	lastAvg = costAvg/songAvg;

	/* display final results */

	printf("\n                    Final Report		\n");
	printf("                    ------------		\n");
	printf("      Customers	   Songs	 Minutes	Cost\n");
	printf("      =========	   =====	 =======	====\n");
	printf("Total   %d        %6.2f	  	%6.2f	      %6.2f\n", numberCust, totalSongs, totalMins, totalCost);
	printf("Average          %6.2f         %6.2f        %6.2f\n", songAvg, minAvg, costAvg);
	printf("\nAverage Cost Per Song:	%6.2f\n", lastAvg);
	printf("\nGoodbye\n");

	return 0;

/* end of program */

}