#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>

int make_temp_dir(char *tmp) {
	if (!mkdtemp(tmp)) {
		if (errno == EINVAL)
			fprintf(stderr, "mktemp: template does not end in exactly 'XXXXX': %s\n", tmp);

		else
			fprintf(stderr, "mktemp: %s\n", strerror(errno));

		return 1;
	}

	return 0;
}

int get_suffix(const char *str) {
	size_t len = strlen(str);
	for (size_t i = len - 1; i > 0; i--)
		if (str[i] == 'X')
			return len - i - 1;

	return 0;
}

int make_temp_file(char *tmp) {
	if (!strstr(tmp, "XXXXXX")) {
		fprintf(stderr, "mktemp: too few X's in template: %s\n", tmp);
		return 1;
	}

	int fd = mkstemps(tmp, get_suffix(tmp));
	if (fd < 0) {
		fprintf(stderr, "mktemp: %s\n", strerror(errno));
		return 1;
	}

	close(fd);
	return 0;
}

int main(const int argc, char **argv) {
	unsigned int d_flag = 0;

	int i;
	for (i = 1; i < argc; i++) {
		if (argv[i][0] != '-')
			break;

		else if (!strcmp(argv[i], "-d"))
			d_flag = 1;

		else if (!strcmp(argv[i], "--help")) {
			printf("mktemp [-d dir] [file]\n");
			return 0;
		}
	}

	if (argc - i == 0) {
		fprintf(stderr, "mktemp: missing operand\n");
		return 1;
	}

	if (argc - 1 > i) {
		fprintf(stderr, "mktemp: extra operands\n");
		return 1;
	}

	char *path = getenv("TMPDIR");
	if (!path || path[0] == '\0')
		path = "/tmp";

	if (chdir(path)) {
		fprintf(stderr, "mktemp: %s\n", strerror(errno));
		return 1;
	}

	if (d_flag) {
		if (make_temp_dir(argv[i]))
			return 1;
	}

	else {
		if (make_temp_file(argv[i]))
			return 1;
	}

	printf("%s/%s\n", path, argv[i]);
	return 0;
}