#define _POSIX_C_SOURCE 200112L

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>
#include <pwd.h>
#include <grp.h>

#include "zpm.h"

/*
 * a generic printf style format string parser
 * takes a character pointer, returns pointer to next non
 * parsed character,  next token, optionally
 * does a callback, fills in a format struct
 */

#if 0
char *fmt;
struct format f;

while (*fmt) {
	fmt = parse_format_str(fmt, &f);
	if (!f.found) break; /* done */
	if (!f.flags) {
		/* literal/noformat */
		putchar(f.found); /* or whatever */
		continue;
	}
	switch (f.found) {
		case 'a': /* handle %a */
			break;
		default: /* handle unknown formatting character */
			break;
	}
}
#endif

struct format_string {
	int found; /* the 'd' in '%d' */
	unsigned flags; /* 1 = found, 0 = none found */
};

char *format_string_parse(char *s, struct format_string *f) {
	f->found = 0;
	f->flags = 0;

	if (!*s) return s; /* done */

	/* literal non-format specifier */
	if (*s != '%') {
		f->found = *s++;
		return s;
	}
	s++;

	f->flags = 1;
	f->found = *s++;
	return s;
}

void stat_one(char *fmt, char *timefmt, char *filename, struct stat *buf) {
	struct tm *tm;
	char timestr[1024];
	struct format_string f;
	struct passwd *pw;
	struct group *gr;

	while (*fmt) {
		fmt = format_string_parse(fmt, &f);
		if (!f.found) break; /* done */
		if (!f.flags) {
			/* literal/noformat */
			putchar(f.found); /* or whatever */
			continue;
		}
		switch (f.found) {
			case 'y': /* handle mtime */
				tm = gmtime(&buf->st_mtime);
				strftime(timestr, 1023, timefmt, tm);
				timestr[1023] = 0;
				printf("%s", timestr);
				break;
			case 's':
				printf("%jd", (intmax_t)buf->st_size);
				break;
			case 'a': /* octal mode */
				printf("%o", (int)buf->st_mode & 07777);
				break;
			case 't':
				if (S_ISBLK(buf->st_mode)) {
					printf("block");
				} else if (S_ISCHR(buf->st_mode)) {
					printf("character");
				} else if (S_ISDIR(buf->st_mode)) {
					printf("directory");
				} else if (S_ISFIFO(buf->st_mode)) {
					printf("fifo");
				} else if (S_ISREG(buf->st_mode)) {
					printf("regular");
				} else if (S_ISLNK(buf->st_mode)) {
					printf("symlink");
				} else if (S_ISSOCK(buf->st_mode)) {
					printf("socket");
				} else {
					printf("unknown");
				}
				break;
			case 'u': /* handle uid */
				printf("%0d", buf->st_uid);
				break;
			case 'U': /* handle username */
				pw = getpwuid(buf->st_uid);
				if (!pw) exit(1);
				printf("%s", pw->pw_name);
				break;
			case 'g': /* handle gid */
				printf("%0d", buf->st_gid);
				break;
			case 'G': /* handle groupname */
				gr = getgrgid(buf->st_gid);
				if (!gr) exit(1);
				printf("%s", gr->gr_name);
				break;
			case 'n':
				printf("%s", filename);
				break;
			case '%':
				putchar('%');
				break;
			default: /* handle unknown formatting character */
				printf("%c", f.found);
				break;
		}
	}
	putchar('\n');
}

int main(int ac, char *av[]) {
	char *fmt = "%y"; /* default stat is mtime */
	char *timefmt = "%s"; /* default time fmt is unix ts */
	int errflg = 0;
	int c;
	int uselstat = 0;

	while ((c = getopt(ac, av, "lf:t:")) != -1) {
		switch(c) {
			case 'f':
				fmt = optarg;
				break;
			case 't':
				timefmt = optarg;
				break;
			case ':':       /* -f or -t without operand */
				fprintf(stderr,
				"Option -%c requires an operand\n", optopt);
				errflg++;
				break;
			case 'l':
				uselstat = 1;
				break;
			case '?':
				fprintf(stderr,
				"Unrecognized option: '-%c'\n", optopt);
				errflg++;
		}
	}
	if (errflg) {
		fprintf(stderr, "zpm-stat [-f <format>] [-t <timefmt>]\n");
		exit(2);
	}
	for ( ; optind < ac; optind++) {
		struct stat buf;
		if (uselstat) {
			lstat(av[optind], &buf);
		} else {
			stat(av[optind], &buf);
		}
		stat_one(fmt, timefmt, av[optind], &buf);
	}
	return 0;
}