// Zeinalipour-Yazti Demetrios
// csyiazti
// cs10xx -
// Lab Sec#24,29,30
// lab8

#include <iostream>
#include <iomanip>
#include <fstream>
#include <string>
#include <cmath>
using namespace std;

/* This program implements a function that takes an integer and an ostream
 * and prints out the value and the digits to the specified ostream.
 * It also reads integers from a user-specified file and uses the above
 * function to print out the digits to a specific location.
 * The user should be able to choose to print to the screen (cout) or a file.
 * If they choose to print to a file, they are able to specify the name of the
 * file to print to.
 */

// the length of the largest number (e.g 1020 => 4)
const int MAX_NUMBER = 4;

void getInStream(ifstream &);
void getOutStream(ofstream &);
int getOutputMethod();
void printC(int number, ostream &allout);


void main ()
{
	// the input filestream & the number read at each line of the file
	ifstream infilestream;
	int number;  // the number read from a line
	string outfile; // the name of the output file.

	int outmethod;
	ofstream outstream;

	cout << "Number Splitting v2 by Demetris Zeinalipour - Lab 8\n\n";

	outmethod = getOutputMethod();

	// this function does all the work related to opening the in file.
	getInStream(infilestream);

	if (outmethod == 1)
	{	// open the file
		getOutStream(outstream);
	}

	// repeat this loop until you reach the end of the input file which
	while (!infilestream.eof())
	{
	    // read integer from the file
	    infilestream >> number;

		// print out the number read from the input file
		if (outmethod == 1)
		{	// File
			printC(number, outstream);
		}
		else if (outmethod == 2)
		{	// Screen
			printC(number, cout);
		}

	}

	// close any opened files
	infilestream.close();
	outstream.close();
}


/* this function takes by reference an ifstream. It tries
 * to connect to the given file. If this operation
 * becomes sucessful it quits.
 */
void getInStream(ifstream& infilestream)
{
        string filename;

        // repeat the loop until the user enters the correct filename
        while (true)
        {
          /* get the filename */
          cout << "Please enter the name of the INPUT file: " ;
          cin >> filename;

          cout << "\nOpening \'" << filename << "\'...";

          /* open file in read mode */
          infilestream.open(filename.c_str());

          // if the file was opened succesful then break this loop
          // else display error message and let him try again
          if (infilestream)
          {
			cout << "done\n";
			break;
          }
          else
          {
			cout << "failed\n";
			cout << "File could not be opened\n" << endl;
          }

		} // while
}

/* this function is sililar to getInStream, with the difference
 * that it tries to connect to the given output file.
 * If this operation becomes sucessful it quits.
 */
void getOutStream(ofstream& outfilestream)
{

	string filename;
	do
	{
		cout << "Please enter the name of the OUTPUT file: ";
		cin >> filename;

		cout << "\nOpening outfile  \'" << filename << "\'...";

		/* open outfile */
		outfilestream.open(filename.c_str());

		if (!outfilestream)
		{
			cout << "failed!\n";
			cout << "File could not be opened!\n" << endl;
		}
		else
		{	cout << "done!\n";
			break;
		}

	} while (true);

}


/* This method allows you to choose between the 2 available
 * output methods. It thens returns
 * @ return : 1  => use that file for output.
 *			: 2  => use screen for output.
 */
int getOutputMethod()
{
	int method;

	// select output method
	do
	{
		cout << "Please select Output Method (1=File, 2=Screen) :";
		cin >> method;

		// error checking
		if (method!=1 && method!=2)
		{	cout << "Error - Only 1-2 are accepted Values!\n\n"; }
		else
		{	break; }

	} while (true);

	return method;
}

/* Visit http://www.cplusplus.com/ref/iostream/ostream/index.html for
 * more information on the Stream Hierarchy
 */
void printC(int number, ostream &allout)
{
	int power;   // variable to be used to define digit
	int digit;   // the digit of a number. Each number will have 4 digits

	allout << setiosflags(ios::left);
	allout << setw(7) << number;

	// split and print each digit of this number
	for (int i=MAX_NUMBER-1; i>=0; i--)
	{
		power = (int)pow(10,i);

		digit  = number /  power;
		number %= power;

		allout << setw(7) << digit;
	}

	allout <<  endl;
}