// Name: cs157a5wrong.c
// Purpose: Developing test cases to catch program errors
// 
// errors purposely added 
//                            
// Author: Dr. Michael A. Redmond
// Date Written: 
// NOTES: 
//

#include <stdio.h>

// Define constants 
const double in_town_high_rate  = 500;
const double in_town_low_rate  = 200;
const double out_town_high_rate  = 1000;
const double out_town_low_rate  = 400;
const int low_cred_cutoff  = 12;
const int max_poss_cred    = 21;
const double disc_adj   = 0.80;


int main()
{
 // Declarations 
 int  credits;
 double cost, high_rate, low_rate;   
 char resid, disc, check_char;
 // int invalid_std;
 // bool invalid_std; // _bool;





      // read input  
      printf("Please enter student's residency (I - intown or O -out of town): ");
      scanf("%c",&resid);    
      scanf("%c",&check_char);    
	  // check residency status         
      while ( (resid != 'I') && (resid != 'O') )
         {
         printf("invalid residence: %c \n",resid);      
		 printf("Please enter student's residency (I - intown or O -out of town): ");      
		 scanf("%c",&resid);     
		 scanf("%c",&check_char); 
         }
  
      printf("Please enter student's discount status (D - discounted or N - not discounted): ");
      scanf("%c",&disc);    
      scanf("%c",&check_char); 
	  // check discount  status         
      if ( (disc != 'D') && (disc != 'N') )
         {
         printf("invalid discount: %c \n",disc);
		 printf("Please enter student's discount status (D - discounted or N - not discounted): ");      
		 scanf("%c",&disc);   
		 scanf("%c",&check_char); 
         }

      printf("Please enter student's number of credits (1-21): ");
      scanf("%d",&credits);
	  // check number of credits        
      while ( (credits <= 1) || (credits > max_poss_cred) )
         {
         printf("invalid credits: %2d \n",credits);
		 printf("Please enter student's number of credits (1-21): ");
		 scanf("%d",&credits);
         }


      // debugging - echo check 
      printf("echo: | %c  |          | %c  |         |  %2d  | \n",resid,disc,credits);

      

		  ////////////////////////////////////////////////////////////////////////////
		  // HERE - based on residency and discount status - determine rates - these are
		  //    then used later in tuition calculation
		  ////////////////////////////////////////////////////////////////////////////
		   // divide based on residence in-town or out-of-town
		  if (resid == 'I') { 
			  // in-town - now determine if discounted or not
			  if (disc == 'N') {
				  // not discounted					
				  printf("In town regular \n");                
				  high_rate = in_town_high_rate;               
				  low_rate = in_town_low_rate;
              }
			  else {
				  // discounted               
				  printf("In town discounted \n");               
				  high_rate = in_town_high_rate * disc_adj;                
				  low_rate = in_town_high_rate * disc_adj;
              }        
		  } // end resid in town
		  // otherwise should be out of town - but make sure
		  else if (resid == 'O') { 
			  // out of town - now determine if discounted or not
			  if (disc == 'N') {
				  // not discounted                
				  printf("Out of town regular \n");                
				  high_rate = out_town_high_rate;                
				  low_rate = out_town_low_rate;             
			  }
			  else {
				  // discounted                  
				  printf("Out of town discounted \n");                
				  high_rate = out_town_high_rate * disc_adj;                
				  low_rate = out_town_low_rate * disc_adj;
              }
		  } // end residence out of town

		  ////////////////////////////////////////////////////////////////////////////
		  // NOW - based on #credits and tuition rates determined above - calculate tuition
		  ////////////////////////////////////////////////////////////////////////////
		  // see if all credits are charged at the higher rates
           if ( credits < low_cred_cutoff ) {
                cost = credits * high_rate;
              }

		   // see if credits are charged at mixed rates
           if ( credits > low_cred_cutoff) {
			   // first credits (12) are charged at higher rate, then rest at lower rate
                cost = (low_cred_cutoff * high_rate) +
                       ((credits - low_cred_cutoff) * low_rate);
              }

           
           // write out header to table here 
           printf("Residency  Discount  Credits    Tuition   \n");
           printf("---------  --------  -------    -------   \n");

		   // write out student info
           printf("    %c         %c       %2d        %7.2f     \n",resid,disc,credits,cost);


 return 0;
}   // end main