#include "main.h"

#include <alloca.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <getopt.h> // Получение опций командной строки
#include <locale.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))

const char *program_name = NULL;
static int exit_status;
static int d_opt = 0;

static int print(const void *buf, size_t count)
{
	int fd_std_out = fcntl(STDOUT_FILENO, F_DUPFD, 0);
	write(fd_std_out, buf, count);
	close(fd_std_out);
}

static void test_sleep()
{
	int err = 0;
	err = sleep(3);
	printf("Err: %d\n", err);
	assert(err == 0);
}

static void set_program_name(const char *argv0)
{
	program_name = argv0;
}

static void usage(int status)
{
	const char const msg_usage_fmt[] = "Usage: %s [OPTION]... [FILE]...\n";
	const char const msg_help[] = "\
Program nothin to do while, this is just dirty example.\n\
Arguments\n\
      --h        display this help and exit\n";

	char * restrict msg_buf;
	size_t size;

	// Allocate enough memory on function stack for usage message
	size = strlen(program_name) + sizeof(msg_usage_fmt) - 2;
	msg_buf = alloca(size);

	size = snprintf(msg_buf, size, msg_usage_fmt, program_name);
	write(STDOUT_FILENO, msg_buf, sizeof(msg_buf[0]) * size);

	// Print usage help message
	write(STDOUT_FILENO, msg_help, sizeof(msg_help));
}

static int decode_switches(int argc, char **argv)
{
	int c;

	while (1)
	{
		c = getopt(argc, argv, "h");
		if (c == -1)
			break;
		
		switch (c)
		{
		case 'h':
			usage(EXIT_SUCCESS);
			break;

		default:
			break;
		}
	}
	
	return optind;
}

static void close_stdout(void)
{
	close(STDOUT_FILENO);
}

int main(int argc, char *argv[])
{
	int fd_std_out;
	int i;

	const size_t msg_maxlen = 255;
	char msg[msg_maxlen + 1];

	set_program_name(argv[0]);
	setlocale(LC_ALL, "");
	atexit(close_stdout);

	exit_status = EXIT_SUCCESS;

	i = decode_switches (argc, argv);
	printf("Обработано аргументов: %d\n", i);

	const char const msg_fmt_argv_handled[] = "Обработано аргументов: %d\n";
	size_t size;
	size = snprintf(msg, msg_maxlen, msg_fmt_argv_handled, i);
	write(STDOUT_FILENO, msg, sizeof(msg[0]) * size);

	// Duplicate descriptor
	fd_std_out = fcntl(STDOUT_FILENO, F_DUPFD, 0);
	assert(fd_std_out != -1);

	const char const msg_example[] = "Функциональность приложения не реализована\n";
	write(STDERR_FILENO, msg_example, sizeof(msg_example)-1);

	/*{
		const char const * err_str = "WARN\n";
		write(STDOUT_FILENO, err_str, sizeof(err_str));
	}*/

	close(fd_std_out);

	return exit_status;
}