//-----------------------------------------------------------------------------
// File:     HelloMath2.cpp
// Class:    None
// Parent:   None
// Children: None
// Purpose:  Tests out various mathematical functions
//-----------------------------------------------------------------------------
// The following are standard C/C++ header files.
// If a filename is enclosed inside < >  it means the header file is in the Include directory.
// If a filename is enclosed inside " "  it means the header file is in the current directory.
#include <ctype.h>      // Character Types
#include <math.h>       // Mathematical Constants
#include <stdarg.h>     // Variable Argument Lists
#include <stdio.h>      // Standard Input/Output Functions
#include <stdlib.h>     // Utility Functions
#include <string.h>     // String Operations
#include <signal.h>     // Signals (Contol-C + Unix System Calls)
#include <setjmp.h>     // Nonlocal Goto (For Control-C)
#include <time.h>       // Time and Date information
#include <assert.h>     // Verify Program Assertion
#include <errno.h>      // Error Codes (Used in Unix system())
#include <float.h>      // Floating Point Constants
#include <limits.h>     // Implementation Constants
#include <stddef.h>     // Standard Definitions
#include <exception>    // Exception handling (e.g., try, catch throw)
#include <iostream>
#include <string>
#include <cstdio>
#include <cstdlib>
#include <fstream>
using namespace std;
//-----------------------------------------------------------------------------
#define PI 3.1415926535
//-----------------------------------------------------------------------------
// Prototypes for local functions (functions not called by code in other files)
//-----------------------------------------------------------------------------
bool   WriteDoubleToFileWithExponentInSpecifiedPrecision( double x, int precision, FILE *fptr );
bool  GetStringFromFile( char inputString[], unsigned long sizeOfString, FILE* fptr);
bool  GetStringFromKeyboard( char inputString[], unsigned long sizeOfString);
bool  WriteStringToScreen ( const char outputString[]);
bool  WriteStringToFile( const char outputString[], FILE *fptr);
const char* ConvertStringToLong( const char *s, long &returnValue, long defaultValue);
double ConvertFromRadiansToDegrees( long angleInDegrees);
double ConvertFromDegreesToRadians( long angleInRadians);
FILE* FileOpenWithMessageIfCannotOpen( const char *filename, const char *attribute);
//-----------------------------------------------------------------------------
int  main( int numberOfCommandLineArguments, char *arrayOfCommandLineArguments[] )
{   
     char inputString[256];
	 const char fileAttributeR[5]="rb";
     const char fileAttributeW[5]="w";
	 WriteStringToScreen("Please enter an integer between 180 and 720:\n");
	 GetStringFromKeyboard(inputString,256);
	 long angleInDegrees;
	 
	 if(ConvertStringToLong(inputString,angleInDegrees,360)==NULL)
	 {
		 WriteStringToScreen("A default value of 360 (for an angle in degrees) will be  used\n");
	 }
	 if(angleInDegrees <180 || angleInDegrees >720 ) 
	 {
		 angleInDegrees=360;
		 WriteStringToScreen("A default value of 360 (for an angle in degrees) will be  used\n");
	 }
     
	 char precision[256];
	 WriteStringToScreen("Please enter the desired precision as an integer\n");
	 GetStringFromKeyboard(precision,256);

	 long returnValueForPrecision;
	 if(ConvertStringToLong(precision,returnValueForPrecision,5)==NULL)
	 {
		 WriteStringToScreen("A default value of 5 for precision will be  used\n");
	 }
     if(returnValueForPrecision <1 || returnValueForPrecision >17 ) 
	 {
		 returnValueForPrecision=5;
		 WriteStringToScreen("A default value of 5 for precision will be  used\n");
	 }
	 FILE *pFile = FileOpenWithMessageIfCannotOpen("HelloMath2.txt",fileAttributeW);
     if (!pFile) return 1;
		        for (int i=1;i<=angleInDegrees;i++)
	            {
				WriteDoubleToFileWithExponentInSpecifiedPrecision(i,returnValueForPrecision,pFile);
				double angleInRadians=ConvertFromDegreesToRadians(i);
				WriteDoubleToFileWithExponentInSpecifiedPrecision(angleInRadians,returnValueForPrecision,pFile);
				WriteDoubleToFileWithExponentInSpecifiedPrecision(sin(angleInRadians),returnValueForPrecision,pFile);
	            WriteDoubleToFileWithExponentInSpecifiedPrecision( cos(angleInRadians),returnValueForPrecision,pFile); 
	            WriteDoubleToFileWithExponentInSpecifiedPrecision(tan(angleInRadians),returnValueForPrecision,pFile);
				WriteStringToFile("\n",pFile);
	            }
	 fclose (pFile);
	 WriteStringToScreen("\n\n Press Enter to terminate the program:");
	 int key = getchar();	 
     return 0;
}
//__________________________________________________________________________________
bool GetStringFromKeyboard( char inputString[], unsigned long sizeOfString)
{
	GetStringFromFile(inputString,256,stdin);
	 return 0;
}   
//_________________________________________________________________________________
bool GetStringFromFile(char inputString[], unsigned long sizeOfString, FILE* fptr)
{
	fgets(inputString,sizeOfString,fptr);
	return 0;
}

//_____________________________________________________________________________________
const char* ConvertStringToLong( const char *s, long &returnValue, long defaultValue)
{
	returnValue = defaultValue;
	if (s)
	{
	char *pointerToCharacterAfterNumber = NULL;
	long x =strtol(s,&pointerToCharacterAfterNumber,0);
	char characterAfterNumber = pointerToCharacterAfterNumber ? *pointerToCharacterAfterNumber : 'z';
		if ( characterAfterNumber == '\0' || isspace (characterAfterNumber) )
		{
			returnValue = x;
			return pointerToCharacterAfterNumber;
        }
    }
return NULL;
}

//___________________________________________________________________________________________
bool  WriteStringToScreen ( const char outputString[])
{
	WriteStringToFile(outputString, stdout);
	return 0;
}
//___________________________________________________________________________________
bool  WriteStringToFile( const char outputString[], FILE *fptr)
{
	fprintf(fptr,outputString);
	return 0;
}
//___________________________________________________________________________________________
double ConvertFromDegreesToRadians( long angleInDegrees)
{     
	 double angleInRadians=angleInDegrees*(PI/180);
	 return angleInRadians;
}

//____________________________________________________________________________________________________________
bool WriteDoubleToFileWithExponentInSpecifiedPrecision(double x, int precision, FILE *fptr)
{
	if (precision < 0 || precision >17) precision =5;
	int fieldWidth =precision +8;
	char format[20];
	sprintf(format," %%- %d.%dE", fieldWidth, precision);
    return fprintf( fptr, format, x) >0;
}
//---------------------------------------------------------------------
FILE* FileOpenWithMessageIfCannotOpen( const char *filename, const char *attribute)
{
	FILE *p2File;
	p2File=fopen(filename,attribute);//"r"
	if (p2File==NULL)
	{
		WriteStringToScreen("Sorry, could not open file that was requested, please check name and re-enter\n");
		return NULL;
	}
	return p2File;
}
//__________________________________________________________________________________________________________