#include <arpa/inet.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>

#include "config.h"

/* 4 extra bytes for the two escape characters (), the action character, and
 * the carriage return (\r) */
static const size_t BUF_SIZE = sizeof(PASSWORD) + 4;

static const char ACTION_ON[]    = "on";
static const char ACTION_OFF[]   = "off";
static const char ACTION_CYCLE[] = "cycle";
static const char ACTION_QUERY[] = "query";

enum action {
	ON      = 'n',
	OFF     = 'f',
	CYCLE   = 'c',
	QUERY   = 'q',
};

int
create_socket()
{
	int sockfd = socket(AF_INET, SOCK_STREAM, 0);
	if (sockfd < 0) {
		fprintf(stderr, "Failed to create socket\n");
		exit(EXIT_FAILURE);
	}

	struct sockaddr_in addr = {
		.sin_family = AF_INET,
		.sin_port = htons(PORT),
		.sin_addr = { .s_addr = inet_addr(ADDRESS) },
	};

	if (connect(sockfd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
		fprintf(stderr, "Failed to connect\n");
		exit(EXIT_FAILURE);
	}

	return sockfd;
}

void
send_command(int sockfd, enum action action)
{
	char buf[BUF_SIZE];
	sprintf(buf, "\x1b%s\x1b%c\r", PASSWORD, action);
	if (write(sockfd, buf, BUF_SIZE) != BUF_SIZE) {
		fprintf(stderr, "partial/failed write\n");
		exit(EXIT_FAILURE);
	}

	memset(buf, 0, BUF_SIZE);
	ssize_t nread = read(sockfd, buf, BUF_SIZE);
	if (nread == -1) {
		perror("read");
		exit(EXIT_FAILURE);
	}

	printf("%s\n", buf);
}

enum action
get_action(const char *action)
{
	if (!strcmp(action, ACTION_ON)) {
		return ON;
	}

	if (!strcmp(action, ACTION_OFF)) {
		return OFF;
	}

	if (!strcmp(action, ACTION_CYCLE)) {
		return CYCLE;
	}

	if (!strcmp(action, ACTION_QUERY)) {
		return QUERY;
	}

	return 0;
}

int
main(int argc, char *argv[])
{
	if (argc < 2) {
		fprintf(stderr, "Usage: %s <on|off|cycle|query>\n", argv[0]);
		exit(EXIT_FAILURE);
	}

	char action = get_action(argv[1]);
	if (!action) {
		fprintf(stderr, "Invalid action: %s\n", argv[1]);
		exit(EXIT_FAILURE);
	}

	int sockfd = create_socket();
	send_command(sockfd, action);

	return EXIT_SUCCESS;
}