#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

void turn_on(float grid[1000][1000], uint16_t x, uint16_t y) {
	grid[x][y] += 1;
}

void turn_off(float grid[1000][1000], uint16_t x, uint16_t y) {
	if (grid[x][y] > 0)
		grid[x][y] -= 1;
}

void toggle(float grid[1000][1000], uint16_t x, uint16_t y) {
	grid[x][y] += 2;
}

void process_instruction(char *line_buffer, 
			 char *delimiters,
			 float grid[1000][1000],
			 void (*operation)(float grid[1000][1000], uint16_t, uint16_t)) {
	uint16_t x1, x2, y1, y2;
	char *token;

	token = strtok(NULL, delimiters);
	x1 = atoi(token);
	token = strtok(NULL, delimiters);
	y1 = atoi(token);
	token = strtok(NULL, delimiters);	//ignore the word "through"
	token = strtok(NULL, delimiters);
	x2 = atoi(token);
	token = strtok(NULL, delimiters);
	y2 = atoi(token);

	for (uint16_t x = x1; x <= x2; x++)
		for (uint16_t y = y1; y <= y2; y++)
			operation(grid, x, y); 
}

int main() {
	FILE *file = fopen("input", "r");
	if (file == NULL) {
		perror("Error opening file.");
		return 1;
	} 
 
	float grid[1000][1000] = {0};

	char delimiters[] = " ,";
	char *token;
	char line_buffer[256];
	while (fgets(line_buffer, sizeof(line_buffer), file) != NULL) {
		token = strtok(line_buffer, delimiters);

		if (!strcmp(token, "toggle")) {
			process_instruction(line_buffer, delimiters, grid, toggle);
			continue;
		}

		if (!strcmp(token, "turn")) {
			token = strtok(NULL, delimiters);
			if (!strcmp(token, "on")) {
				process_instruction(line_buffer, delimiters, grid, turn_on);
				continue;
			}

			if (!strcmp(token, "off")) {
				process_instruction(line_buffer, delimiters, grid, turn_off);
				continue;
			}
		}
	}
	if (ferror(file)) {
		perror("main: Error reading from file.");
		return 1;
	}
	fclose(file); 

	uint32_t brightness = 0;
	for (uint16_t x = 0; x <= 999; x++)
		for (uint16_t y = 0; y <= 999; y++)
			brightness += grid[x][y];

	printf("brightness: %u\n", brightness);

	return 0;
}