/*
   asst04x.cpp
   7/6/2005
   CIS 150
   David G. Klick
   
   Demonstration of what would happen to the assignment #4
   solution if you didn't have user-defined functions available.
*/

#include <iostream>
#include <iomanip>
using std::cin;
using std::cout;
using std::fixed;
using std::showpoint;
using std::setprecision;

int main(void) {
   const double PI = 3.1415926536;
   char choice;
   double area;
   bool valid;
   char *ptr;
   double length, width;
   double base, height;
   double side, radius;
   double num;
      
   char *menu = "Area Calculator Menu:\n\n"
      "   (R)ectangle\n\n"
      "   (C)ircle\n\n"
      "   (H)exagon\n\n"
      "   (T)riangle\n\n"
      "   E(x)it\n\n";
   
   do {
      // display menu
      cout << menu;
	  
      // get user choice
      do {
         cout << "Enter choice: ";
         cin >> choice;
         ptr = strchr("RrCcTtHhXx", (int)choice);
         if (ptr == NULL) {
            cout << "Error: Invalid choice\n";
         }
      } while (ptr == NULL);

      choice = toupper(choice);
      valid = true;
	  
      // process choice
      switch (choice) {
      case 'R':
         do {
            cout << "Enter length (0-300): ";
            cin >> num;
            if (num<0.0) {
               cout << "Error: Input below minimum\n";
            } else if (num>300.0) {
               cout << "Error: Input above maximum\n";
            }
         } while (num<0.0 || num>300.0);
         length = num;
         do {
            cout << "Enter width (0-300): ";
            cin >> num;
            if (num<0.0) {
               cout << "Error: Input below minimum\n";
            } else if (num>300.0) {
               cout << "Error: Input above maximum\n";
            }
         } while (num<0.0 || num>300.0);
         width = num;
         area = length * width;
         break;
	   case 'C': 
         do {
            cout << "Enter radius (0-250): ";
            cin >> num;
            if (num<0.0) {
               cout << "Error: Input below minimum\n";
            } else if (num>250.0) {
               cout << "Error: Input above maximum\n";
            }
         } while (num<0.0 || num>250.0);
         radius = num;
         area = PI * radius * radius;
         break;
      case 'H':
         do {
            cout << "Enter side (0-200): ";
            cin >> num;
            if (num<0.0) {
               cout << "Error: Input below minimum\n";
            } else if (num>200.0) {
               cout << "Error: Input above maximum\n";
            }
         } while (num<0.0 || num>200.0);
         side = num;
         area = side * side * 2.598075;
         break;
      case 'T':
         do {
            cout << "Enter height (0-200): ";
            cin >> num;
            if (num<0.0) {
               cout << "Error: Input below minimum\n";
            } else if (num>200.0) {
               cout << "Error: Input above maximum\n";
            }
         } while (num<0.0 || num>200.0);
         height = num;
         do {
            cout << "Enter base (0-200): ";
            cin >> num;
            if (num<0.0) {
               cout << "Error: Input below minimum\n";
            } else if (num>200.0) {
               cout << "Error: Input above maximum\n";
            }
         } while (num<0.0 || num>200.0);
         base = num;
         area = 0.5 * height * base;
         break;
      default:
         valid = false;
      }

      // display area if appropriate
      if (valid) {
         cout << "The area is " << fixed << showpoint
              << setprecision(2) << area << "\n\n";
      }

   // continue while user did not choose to exit
   } while (choice != 'X');

   return 0;
}