// header files
#include "StandardConstants.h"
#include "Console_IO_Utility.h"
#include "File_Input_Utility.h"
#include "File_Output_Utility.h"

// function prototypes

/*
Name: calculateNetRevenue
Process: opens input file calculates net revenue based on expenses and
         gross revenue; uses total years to iterate over expenses file;
         makes sure expenses are negative number before adding/subtracting
Function input/parameters: file name (const char *), grossRevenue and totalYears
Function output/parameters: none
Function output/returned: net revenue (grossRevenue - expenses)
Function input/keyboard: none
Device output/file: none
Dependencies: File Output Utility tools
*/
double calculateNetRevenue( const char *expensesDataFile,
                            double grossRevenue,
                            int totalYears);


// main program
int main()
    {
     // initialize variables, functions
        char expensesDataFile[ STD_STR_LEN ];
        double grossRevenue, netRevenue;
        int totalYears;

    // show title
        // function: printf
    printf( "\nSimple Accountant Script\n" );
    printf( "==========================\n\n" );

    // get input
    grossRevenue = promptForDouble("Enter gross revenue: ");
    totalYears = promptForInteger("Enter number of years: ");
    //printf("Enter file name containing expenses information: ");
    //scanf("%c\n", expensesDataFile);
    promptForString("Enter file name containing expenses information: ",
                                                              expensesDataFile);


    // processing
    netRevenue =
                calculateNetRevenue(expensesDataFile, grossRevenue, totalYears);

    // display results
    printf("\nThe total revenue in %d years is: $%.2f.\n\n",
                                                        totalYears, netRevenue);

    // end program
    printf("End Program\n");
    return 0;

}


// supporting functions
double calculateNetRevenue( const char *expensesDataFile,
                            double grossRevenue,
                            int totalYears)
   {
    // initialize variables
    int iterateNumber;
    int forCounter;
    double saveTotalNumberExpenses;
    double capturedOutput;
    iterateNumber = 0;
    saveTotalNumberExpenses = 0;
    capturedOutput = 0;

    // get input
        // input passed in from function parameters

    // do calculations
        // functions: openInputFile, readDoubleFromFile, checkForInputFileOpen,
        // checkForEndOfInputFile, closeInputFile
    // open the file
    openInputFile(expensesDataFile);

    // use a loop to iterate over the file given number of years.
    for(forCounter = iterateNumber; forCounter < totalYears; forCounter++)
    {
    // capture output number
      capturedOutput = readDoubleFromFile();

    // check if captured output number is negative
      if(capturedOutput < 0)
      {
        // total the number of expenses
        saveTotalNumberExpenses = saveTotalNumberExpenses - capturedOutput;
      }
      else
      {
        // if the data is positive, subtract it twice.
        capturedOutput = capturedOutput - capturedOutput - capturedOutput;
        saveTotalNumberExpenses = saveTotalNumberExpenses - capturedOutput;
      }

    }
    // close input file
    closeInputFile(expensesDataFile);



    // display results
        // no displayed output, returns only.

    // return results
        // returns grossRevenue - saveTotalNumberExpenses
    return grossRevenue - saveTotalNumberExpenses;

    // end function

   }