/*  UPS.cpp
 *  CS401 - Intro to Comp Sci, summer 2001
 *  University of Pittsburgh
 *
 *  The functions below represent a C++ solution to the UPS rules regarding
 *  package classification.  This implementation provides a top level function
 *  called classify() that returns the classification number (details below).
 *  See http://www.ups.com/using/services/packaging/oversize-guide.html
 *  for more information.
 *
 *  Throughout the code, distances are measured in inches, and weights are
 *  measured in pounds.
 *
 *  Note:  I've used ints here, but doubles would be superior if you needed
 *    better precision.  The thought is that UPS is probably cool with an
 *    approximation as long as you're within an inch or a pound.
 *
 *  Note2:  The main() function is just ONE way that these functions could be
 *    used.  It could be that they are called by other software packages that
 *    need the classifications, or perhaps from an automated phone system that
 *    UPS uses for callers that need packages classified at home.
 */

#include <iostream>
#include <iomanip>
#include <string>
#include <conio>		// for getch()
using namespace std;

// Prototypes - see the function defintions for details
void displayGreeting();
void displayResults(int, int, int, int);

int classify(int, int, int, int);	// input is length, longwidth, shwidth, wt
int calcGirth(int, int);		// input is longwidth and shortwidth
bool oversize1(int, int, int);		// input is length, girth, and wt
bool oversize2(int, int, int);

int main() {

	// variables
	int length, shortWidth, longWidth, weight;
	int packageCount, regCount=0, os1Count=0, os2Count=0, invalidCount=0;

	// input
	displayGreeting();
	cout << "How many packages do you have today? ";
	cin >> packageCount;
	cout << endl;

	for (int i=0; i<packageCount; i++) {
		cout << "PACKAGE #" << i << endl;
		cout << "  Enter the length (in inches): ";
		cin >> length;
		cout << "  Enter the width of the longest side (in inches): ";
		cin >> shortWidth;
		cout << "  Enter the width of the shorter side (in inches): ";
		cin >> longWidth;
		cout << "  Enter the weight (in pounds): ";
		cin >> weight;
		cout << endl;

		int classification = classify(length, longWidth, shortWidth, weight);
		switch (classification) {
			case 0: {
         				cout << "That is a regular package.\n\n";
					regCount++;
				}
				break;
			case 1: {
					cout << "That is an oversize1 package.\n\n";
					os1Count++;
				}
				break;
			case 2: {
					cout << "That is an oversize2 package.\n\n";
					os2Count++;
				}
            			break;
			case -1: {
					cout << "That is an invalid package.\n\n";
					invalidCount++;
				}
				break;
			default: cout << "something went wrong.\n\n";
		} // end switch
	} // end for

	displayResults(regCount, os1Count, os2Count, invalidCount);

	cout << "That's it!  Hit the space bar to exit the program.";
	getch();
}

// PACKAGE CLASSIFICATION FUNCTIONS

// calcGirth:  function to calculate the girth of a package
//   input:  the long width and the short width of a box
//	  returns:  the distance around the box
int calcGirth(int lw, int sw) {
	return (2*(lw+sw));
}

// oversize1() and oversize2():  functions to determine if OS1 or OS2 apply
//    input:  the length (bottom to top), girth, and weight of a box
//    returns:
bool oversize1(int len, int g, int wt) {
	return ( (len + g > 84)
		&& (len + g <= 108)
		&& (wt < 30) );
}

bool oversize2(int len, int g, int wt) {
	return ( (len + g > 108) && (wt < 70) );
}

// classify(): top-level function
//   input:  length, long width, short width, weight
//   returns:  0 if regular, 1 if OS1, 2 if OS2, -1 if there was a problem
int classify(int len, int lwidth, int swidth, int wt) {

	// first weed out impossible packages
	if ((len <= 0) || (lwidth <= 0) || (swidth <= 0) || (wt <= 0))
		return -1;

	// calculate the girth
	int girth = calcGirth(lwidth, swidth);

	// see if the package is unshippable (too large in some way)
	if ((len > 108) || (wt >= 70) || (len + girth > 130))
		return -1;

	// now handle the two easy classifications (we have functions for them)
	if (oversize1(len, girth, wt))
		return 1;

	if (oversize2(len, girth, wt))
		return 2;

	// if we made it here, we've got a regular package
	return 0;
}


// OTHER (HELPER) FUNCTIONS

// greeting function
void displayGreeting() {
	cout << "This program will classify your UPS packages "
		<< "(assuming they are in boxes).\n\n"
		<< "Please measure the following things:\n"
		<< "  1. the length in inches (or height, from top to bottom).\n"
		<< "  2. the width of the longest side in inches\n"
		<< "  3. the width of the shortest side in inches\n"
		<< "  4. the weight of your package in pounds\n\n";

	cout << "hit the space bar when you're ready to start.\n\n";
	getch();
}

// displays the final results
void displayResults(int rct, int os1ct, int os2ct, int ict) {
	cout << "Package totals:\n";
	cout << "  regular packages\t" << setw(8) << rct << endl
		<< "  oversize1 packages\t" << setw(8) << os1ct << endl
		<< "  oversize2 packages\t" << setw(8) << os2ct << endl
		<< "  invalid packages\t" << setw(8) << ict << endl << endl;

}

// end UPS.cpp