//Amelia Fass
//Got help from programming lab
#include <fstream>
#include <iostream>
#include <string>
#include <sstream>
#include <vector>
#include <iomanip>
using namespace std;
class PgmPicture
{
private:
	short picture[1024][1024];
	//represents number of rows and columns in pgm image
	int numRows, numCols;
	//constructor intitializes numrows and numcols to 0
public:
	PgmPicture();
	//reads pgm file into object, returns false if fails to open inputfile
	bool readPgmFile(string inputfile);
	//writes pgm image to output file, should return 0(succeeds),-1(pgm image unitnitialized)
	//or -2(function failed to open outputfile)
	int writePgmFile(string outputFile);
	void makeNegative ();
	void hflip();
	void vflip();
};

int main(int argc, char **argv)
{
	if(argc != 3) {
		perror("fail");
		return -1;
	}
	PgmPicture mypic;
	mypic.readPgmFile(argv[1]);
	//mypic.makeNegative();
	//mypic.hflip();
	mypic.vflip();
	mypic.writePgmFile(argv[2]);

	return 0;
}
PgmPicture::PgmPicture()
{
	numRows = 0;
	numCols = 0;
}

bool PgmPicture::readPgmFile(string inputfile)
{
	ifstream fin;
	int i,j,pixel;
	string string;
	fin.open(inputfile.c_str());
	if (fin.fail()) {
		return false;
	} else {
		fin  >>string >> numCols >> numRows>>pixel;
		for (i=0; i < numRows; i++) {
			for (j=0; j < numCols; j++) {
				fin >> pixel;
				picture[i][j] = pixel;

			}
		}
		fin.close();
		return true;

	}
}
int PgmPicture::writePgmFile(string outputFile)
{
	int i,j;
	ofstream fout;
	fout.open(outputFile.c_str());
	if(fout.fail()) {
		perror("fail");
		return -2;
	}
	fout << "P2 " << numCols << " " << numRows << endl << "255" <<endl;
	for (i = 0; i < numRows; i++) {
		for (j=0; j < numCols; j++) {
			fout << picture[i][j] << " ";
		}
		fout << endl;
	}
	fout.close();
	if (numRows == 0) {
		perror("Error: Tried to output an uninitialized pgm object");
		return -1;
	} else

		return 0;

}
void PgmPicture:: makeNegative ()
{
	int i,j;
	for (i = 0; i < numRows; i++) {
		for (j=0; j < numCols; j++) {
			picture[i][j] = 255 - picture[i][j];
		}
	}
	return;
}
void PgmPicture::hflip(){
	int i,j;
	short tmp;
	for ( i = 0; i < numRows; i++){
		for(j = 0;j < (numCols/2);j++){
			tmp=picture[i][j];
			picture[i][j]=picture[i][numCols-j-1];
			picture[i][numCols-j-1]=tmp;

}
	}
	return;
}
void PgmPicture::vflip(){
	int i,j;
	short tmp;
	for ( i = 0; i < (numRows/2); i++){
		for(j = 0;j < numCols;j++){
			tmp=picture[i][j];
			picture[i][j]=picture[numRows-i][j];
			picture[numRows-i][j]=tmp;
		}
}

}