#include <stdio.h>
 
#include "VeryLongInt.h"
 
int InitializeFromFile(char* fileName, VeryLongInt* &x, VeryLongInt* &y);
//void ShowScreen();
 
int main(int argc, char* argv[]){
	char* inputFile;
	char* outputFile;
	if (argc < 2){
		printf("Usage: LongIntDataType.exe [InputFile] [OutputFile]\n");
		printf("Using default configuration: LongIntDataType.exe input.txt output.txt\n\n");
		inputFile = "input.txt";
		outputFile = "output.txt"; // "output/output.txt"
	} else {
		inputFile = argv[1];
		if (argc == 2)
			outputFile = "output.txt";
		else
			outputFile = argv[2];
	}
 
	VeryLongInt *x, *y, *z;
	int succ = InitializeFromFile(inputFile, x, y);
	if (!succ) return 0;
 
	z = VeryLongInt::Add(x, y);
	z->SaveToFile(outputFile, 0);
	delete z;
 
	z = VeryLongInt::Subtract(x, y);
	z->SaveToFile(outputFile, 1);
	delete z;
 
	z = VeryLongInt::Multiply(x, y);
	z->SaveToFile(outputFile, 1);
	delete z;
 
	z = VeryLongInt::Div(x, y);
	if (z != NULL){
		z->SaveToFile(outputFile, 1);
		delete z;
	} // else FW: write NULL to file for checking students' result
 
	z = VeryLongInt::Mod(x, y);
	if (z != NULL) {
		z->SaveToFile(outputFile, 1);
		delete z;
	} // else FW: write NULL to file for checking students' result
 
	// Calculate x^10
	z = VeryLongInt::Power(x, 10);
	z->SaveToFile(outputFile, 1);
	delete z;
 
	delete x;
	delete y;
 
//	ShowScreen();
 
	return 1;
}
 
// Note: I have not optimized this function yet. Anyways, it works
// It's easier to use fgets function but it's not efficient for memory.
int InitializeFromFile(char* fileName, VeryLongInt* &x, VeryLongInt* &y){
	FILE *fptr;
	char* buffer;
	char c;
	fopen_s(&fptr, fileName, "r");
	if (fptr == NULL){
		printf("Can't open file [%s]", fileName);
		return 0;
	}
	// Read the first number
	int count = 0;
	int ok = 1;
	while (!feof(fptr) && ok){
		c = fgetc(fptr);
		if (c != '\n')
			count++;
		else ok = 0;
	}
	fseek(fptr,0, 0);
	buffer = new char[count+1];// +1 for NULL character
	buffer[count] = '\0';
	count = 0;
	ok = 1;
	while (!feof(fptr) && ok){
		c = fgetc(fptr);
		if (c != '\n'){
			buffer[count] = c;
			count++;
		} else ok = 0;
	}
	x = VeryLongInt::Parse(buffer);
	delete buffer;
 
	// Read the second number
	int secondCount = 0;
	ok = 1;
	while (!feof(fptr) && ok){
		c = fgetc(fptr);
		if (c != '\n'){
			secondCount++;
		} else ok = 0;
	}
	buffer = new char[secondCount+1];// +1 for NULL character
	buffer[secondCount] = '\0';
 
	fseek(fptr, count+2, 0);
	secondCount = 0;
	ok = 1;
	while (!feof(fptr) && ok){
		c = fgetc(fptr);
		if (c != '\n'){
			buffer[secondCount] = c;
			secondCount++;
		} else ok = 0;
	}
	y = VeryLongInt::Parse(buffer);
	delete buffer;
	fclose(fptr);
	return 1;
}
 
 
void ShowScreen(){
	VeryLongInt *x = new VeryLongInt(998);
	VeryLongInt *y = new VeryLongInt(9);
	VeryLongInt *z;
 
	printf("Simulation of operators between 2 very long integers\n");
	printf("Sum:\t\t");
	z = VeryLongInt::Add(x, y);
	x->Print(); printf(" + "); y->Print();
	printf(" = "); z->Print(); printf("\n");
	delete z;
 
	printf("Subtract:\t");
	z = VeryLongInt::Subtract(x, y);
	x->Print(); printf(" - "); y->Print();
	printf(" = "); z->Print(); printf("\n");
	delete z;
 
	printf("Multiply:\t");
	x->Print(); printf(" * "); y->Print();
	z = VeryLongInt::Multiply(x, y);
	printf(" = "); z->Print(); printf("\n");
	delete z;
 
	printf("DIV:\t\t");
	x->Print(); printf(" / "); y->Print();
	z = VeryLongInt::Div(x, y);
	printf(" = "); z->Print(); printf("\n");
	delete z;
 
	printf("MOD:\t\t");
	z = VeryLongInt::Mod(x, y);
	x->Print(); printf(" %% "); y->Print();
	printf(" = "); z->Print(); printf("\n");
	delete z;
 
	delete x;
	delete y;
 
	x = VeryLongInt::Parse("-23234");
	y = VeryLongInt::Parse("256");
 
	if (VeryLongInt::Compare(x, y) == -1){
		printf("First number is less than second number.\n");
	} else 
		printf("First number isnot less than second number.\n");
 
	z = VeryLongInt::Add(x, y);
	printf("Sum:\t\t");
	x->Print(); printf(" + "); y->Print(); printf(" = "); z->Print();
	printf("\n");
	delete z;
	printf("Subtract:\t");
	z = VeryLongInt::Subtract(x, y);
	x->Print(); printf(" - "); y->Print(); printf(" = "); z->Print();
	printf("\n");
	delete z;
 
	x->Print(); printf("^10 = ");
	z = VeryLongInt::Power(x, 10);
	char *temp = z->ToString();
	printf("%s\n", temp);
	delete temp;
 
	delete z;
 
	delete x;
	delete y;
}

class VeryLongInt{
public:
	VeryLongInt();
	VeryLongInt(int val); // convert an integer into VeryLongInt object
	~VeryLongInt(); 
 
	VeryLongInt* Clone(); // return another copy of current object (replicate the current object)
	int GetSign(); // return sign of current number
	void ToggleSign(); // toggle sign of current number
	char* ToString(); // convert current object into string
	void Print(); // output current number to console by using printf() function
	int SaveToFile(char* fileName, int appendFlag);// output to file. appendFlag: +1: append, 0: overwrite
 
	static VeryLongInt* Add(VeryLongInt *x, VeryLongInt *y); // x + y
	static VeryLongInt* Subtract(VeryLongInt *x, VeryLongInt *y); // x - y
	static VeryLongInt* Multiply(VeryLongInt *x, VeryLongInt *y); // x * y
	static VeryLongInt* Div(VeryLongInt *x, VeryLongInt *y); // x div y
	static VeryLongInt* Mod(VeryLongInt *x, VeryLongInt *y); // x % y
	static VeryLongInt* Power(VeryLongInt *x, int n); // x^n
	static int EqualTo(VeryLongInt *x, VeryLongInt *y); // x == y?
	static int Compare(VeryLongInt *x, VeryLongInt *y); // return +1 if x > y; 0 if x = y; -1 if x < y
	static VeryLongInt* Parse(char *str); // convert a string into a very long integer
	// Add your neccessary methods here ...
};