// This program prints a simple form letter reminding a customer
// of an overdue account balance.
#include <iostream>
#include <cctype>
#include <cstring>
using namespace std;

// Function Prototypes
void printLetter(char *, char *, char *, char *, char *);
void getInfo(char *, char *, char *, char *, char *);
void getSal(char *);
void printline(const char *, int&);

// Strings that make up the form letter
const char part1[] = "Dear ";
const char part2[] = "Our records show that your account has a"
                     " balance of $";
const char part3[] = " and a past due amount of $";
const char part4[] = "Your last payment was on ";
const char part5[] = "Since we haven't heard from you in some"
                     " time, would you please take a moment to send"
                     " us a check for the past due amount? We value"
                     " your business and look forward to serving you"
                     " in the future.\n\n";
const char part6[] = "Sincerely,\n";
const char part7[] = "The Management\n\n";
const char part8[] = "P.S. If you've already sent your payment, ignore"
                     " this reminder.";

int main()
{
   char salutation[4];    // To hold the salutation
   char lastName[16];     // Customer's last name
   char lastPayment[11];  // Date of last payment
   char balance[9];       // Account balance
   char pastDue[9];       // Amount past due
   char again;            // To hold Y or N

   do
   {
      // Call getInfo to get input from the user
      getInfo(salutation, lastName, balance, pastDue,
              lastPayment);
      cout << "\n\n";
      // Now print the form letter
      printLetter(salutation, lastName, balance, pastDue,
                  lastPayment);
      cout << "\n\nDo another letter? (Y/N) ";
      cin >> again;
   } while (toupper(again) == 'Y');
   return 0;
}

//*****************************************************************
// Definition of function getInfo.                                *
// This function allows the user to enter the following items:    *
// salutation, last name, account balance, past due amount, and   *
// date of last payment. The function arguments are pointers to   *
// strings where the input will be stored.                        *
//*****************************************************************

void getInfo(char *sal, char *lname, char *bal, char *due,
           char *lastPay)
{
   getSal(sal);
   cout << "Last Name: ";
   cin >> lname;
   lname[0] = toupper(lname[0]);
   cout << "Account balance: ";
   cin >> bal;
   cout << "Past due Amount: ";
   cin >> due;
   cout << "Date of last payment (MM/DD/YYYY): ";
   cin >> lastPay;
}

//****************************************************************
// Definition of function getSal.                                *
// This function gives the user a menu from which to pick a      *
// suitable title for the letter's addressee. The choices are    *
// Mr. and Ms. The choice will be copied to the address pointed  *
// to by sal.                                                    *
//****************************************************************

void getSal(char *sal)
{
   int choice;

   do
   {
      cout << "salutation:\n";
      cout << "\t1) Mr.\n";
      cout << "\t2) Ms.\n";
      cout << "Select one: ";
      cin >> choice;
   } while (choice != 1 && choice != 2);

   if (choice == 1)
      strcpy(sal, "Mr.");
   else
      strcpy(sal, "Ms.");
}

//*************************************************************
// Definition of function printLetter.                        *
// This function prints the form letter. The parameters are   *
// pointers to the fields that contain user input.            *
//*************************************************************

void printLetter(char *sal, char *lname, char *bal, char *due,
                 char *lastPay)
{
   int position;

   // Print the salutation part of the letter
   position = 0; // Start a new line.
   printline(part1, position);
   cout << sal << " " << lname << ":" << endl << endl;

   // Print the body of the letter
   position = 0; // Start a new line.
   printline(part2, position);
   cout << bal;  // Print account balance.

   // Add length of balance to position.
   position += strlen(bal);
   printline(part3, position);
   cout << due << ". ";     // Print past due amount
   position += strlen(due)+ 2;

   // Add length of due and the period and space at the
   // end of the sentence to position.
   printline(part4, position);
   cout << lastPay << ". "; // Print date of last payment.

   // Now Add length of lastPay and the period and space at the
   // end of the sentence to position.
   position += strlen(lastPay) + 2;
   printline(part5, position);

   // Print the closing.
   position = 0; // Start a new line.
   printline(part6, position);
   position = 0; // Start a new line.
   printline(part7, position);

   // Pring the PS reminder.
   position = 0; // Start a new line.
   printline(part8, position);
}

//*******************************************************************
// Definition of function printline.                                *
// This function has two parameters: line and startCount.           *
// The string pointed to by line is printed. startCount is the      *
// starting position of the line in an 80 character field. There    *
// are 10-character left and right margins within the 80            *
// character field. The function performs word-wrap by looking      *
// for space character within the line at or after the 60th         *
// character. A new line is started when a space is found, or the   *
// end of the field is reached.                                     *
//*******************************************************************

void printline(const char *line, int &startCount)
{
   int charCount = 0;

   if (startCount >= 70) // If the line is already at
   {                     // or past the right margin...
      cout << "\n";      // Sart a new line.
      startCount = 0;    // Reset startCount.
   }

   // The following while loop cycles through the string
   // printing it one character at a time. It watches for
   // spaces after the 60th position so word-wrap may be
   // performed.
   while (line[charCount] != '\0')
   {
      if (startCount >= 60 && line[charCount] == ' ')
      {
         cout << "          \n";  // Print right margin.
         charCount++;             // Skip over the space.
         startCount = 0;
      }
      if (startCount == 0)
      {
         cout << "          ";  // Print left margin.
         startCount = 10;
      }
      cout.put(line[charCount]); // Print the character.
      charCount++;               // Update subscript.
      startCount++;              // Update position counter.
   }
}