#include <vector>
#include <iostream>
#pragma warning(disable:4996)
#define _CRT_SECURE_NO_DEPRECATE
using namespace std;

typedef unsigned char uchar;

struct RGB {
    uchar R;
    uchar G;
    uchar B;
};
struct Image {
	char format[2];
	size_t width;
	size_t height;
	size_t grade;
	size_t size;
	vector<RGB> imageP6;
    vector<uchar> imageP5;
};

enum Command {
	REVERS = 0,
	HORIZONTAL_MIRROR = 1,
	VERTICAL_MIRROR = 2,
	LEFT_ROTATE = 3,
	RIGHT_ROTATE = 4
};

void ReadImage(char* file, Image& image) {
	FILE* f = fopen(file, "rb");
	if (f == nullptr)
		throw exception("ERROR. File not opend");
	fscanf(f, "%c%c\n%lu %lu\n%lu\n", &image.format[0], &image.format[1], &image.width, &image.height, &image.grade);
	if (!strcmp(image.format, "P5") || !strcmp(image.format, "P6"))
		throw exception("ERROR. Unknow format");
	if (image.width < 0 || image.height < 0 || image.grade != 255)
		throw exception("ERROR. Bad header");
	image.size = image.width * image.height;
	uchar* buffer = new uchar[image.size * 3];
	fread(buffer, sizeof(uchar), image.size * 3, f);
	fclose(f);
	image.imageP6.resize(image.size);
	for (size_t i = 0; i < image.size; i++) {
		image.imageP6[i].R = buffer[i * 3 + 0];
		image.imageP6[i].G = buffer[i * 3 + 1];
		image.imageP6[i].B = buffer[i * 3 + 2];
	}
	delete[] buffer;
}
void WriteImage(char* file, Image& image) {
	FILE* f = fopen(file, "wb");
	if (strcmp(image.format, "P6")) {
		if (strcmp(file, ".pgm")) {
			throw exception("ERROR. Formats not converge");
		}
	}
	else {
		if (strcmp(file, ".pnm")) {
			throw exception("ERROR. Formats not converge");
		}
	}
	if (f == nullptr)
		throw exception("ERROR. File not opend");
	fprintf(f, "%c%c\n%lu %lu\n%d\n", image.format[0], image.format[1], image.width, image.height, image.grade);
	uchar* buffer = new uchar[image.size * 3];
	for (size_t i = 0; i < image.size; i++) {
		buffer[i * 3 + 0] = image.imageP6[i].R;
		buffer[i * 3 + 1] = image.imageP6[i].G;
		buffer[i * 3 + 2] = image.imageP6[i].B;
	}
	fwrite(buffer, sizeof(uchar), image.size * 3, f);
	delete[] buffer;
	fclose(f);
}

void ReversImage(Image& image) {
	for (size_t y = 0; y < image.height; y++) {
		for (size_t x = 0; x < image.width; x++) {
			image.imageP6[y * image.width + x].R = -image.imageP6[y * image.width + x].R;
			image.imageP6[y * image.width + x].G = -image.imageP6[y * image.width + x].G;
			image.imageP6[y * image.width + x].B = -image.imageP6[y * image.width + x].B;
		}
	}
}
void HorisontalMirrorImage(Image& image) {
	for (size_t y = 0;  y < image.height / 2; y++) {
		for (size_t x = 0; x < image.width; x++) {
			swap(image.imageP6[y * image.width + x].R, image.imageP6[image.size - image.width - y * image.width + x].R);
			swap(image.imageP6[y * image.width + x].G, image.imageP6[image.size - image.width - y * image.width + x].G);
			swap(image.imageP6[y * image.width + x].B, image.imageP6[image.size - image.width - y * image.width + x].B);
		}
	}
}
void VerticalMirrorImage(Image& image) {
	for (size_t y = 0; y < image.height; y++) {
		for (size_t x = 0; x < image.width / 2; x++) {
			swap(image.imageP6[y * image.width + x].R, image.imageP6[y * image.width + image.width - 1 - x].R);
			swap(image.imageP6[y * image.width + x].G, image.imageP6[y * image.width + image.width - 1 - x].G);
			swap(image.imageP6[y * image.width + x].B, image.imageP6[y * image.width + image.width - 1 - x].B);
		}
	}
}
void LeftRotateImage(Image& image) {

}
void RightRotateImage(Image& image) {

}

int main(int argc, char** argv) {
	try {
		if (argc > 4)
			throw exception("ERROR. Many argumets");
		if (argc < 4)
			throw exception("ERROR. Few argumets");
		Image image;
		ReadImage(argv[1], image);
		switch (atoi(argv[3]))
		{
		case REVERS:
			ReversImage(image);
			break;
		case HORIZONTAL_MIRROR:
			HorisontalMirrorImage(image);
			break;
		case VERTICAL_MIRROR:
			VerticalMirrorImage(image);
			break;
		case LEFT_ROTATE:
			LeftRotateImage(image);
			break;
		case RIGHT_ROTATE:
			RightRotateImage(image);
			break;
		default:
			throw exception("ERROR. Command not found");
			break;
		}
		WriteImage(argv[2], image);
		cout << "Success!" << endl;
	}
	catch (const exception& error) {
		cerr << error.what() << endl;
		return -1;
	}
	return 0;
}