/* See LICENSE file for copyright and license details. */
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#include "../fs.h"
#include "../util.h"

int recurse_status = 0;

void
recurse(int dirfd, const char *name, void *data, struct recursor *r)
{
	struct dirent *d;
	struct history *new, *h;
	struct stat st, dst;
	DIR *dp;
	int flags = 0, fd;
	size_t pathlen = r->pathlen;

	if (dirfd == AT_FDCWD)
		pathlen = estrlcpy(r->path, name, sizeof(r->path));

	if (r->follow == 'P' || (r->follow == 'H' && r->depth))
		flags |= AT_SYMLINK_NOFOLLOW;

	if (fstatat(dirfd, name, &st, flags) < 0) {
		if (!(r->flags & SILENT)) {
			weprintf("stat %s:", r->path);
			recurse_status = 1;
		}
		return;
	}
	if (!S_ISDIR(st.st_mode)) {
		r->fn(dirfd, name, &st, data, r);
		return;
	}

	new = emalloc(sizeof(struct history));
	new->prev  = r->hist;
	r->hist    = new;
	new->dev   = st.st_dev;
	new->ino   = st.st_ino;

	for (h = new->prev; h; h = h->prev)
		if (h->ino == st.st_ino && h->dev == st.st_dev)
			return;

	if (!r->depth && (r->flags & DIRFIRST))
		r->fn(dirfd, name, &st, data, r);

	if (!r->maxdepth || r->depth + 1 < r->maxdepth) {
		fd = openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_DIRECTORY);
		if (fd < 0) {
			weprintf("open %s:", r->path);
			recurse_status = 1;
		}
		if (!(dp = fdopendir(fd))) {
			if (!(r->flags & SILENT)) {
				weprintf("fdopendir:");
				recurse_status = 1;
			}
			return;
		}
		if (r->path[pathlen - 1] != '/')
			pathlen += estrlcpy(r->path + pathlen, "/", sizeof(r->path) - pathlen);
		if (r->follow == 'H')
			flags |= AT_SYMLINK_NOFOLLOW;
		while ((d = readdir(dp))) {
			if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
				continue;
			r->pathlen = pathlen + estrlcpy(r->path + pathlen, d->d_name, sizeof(r->path) - pathlen);
			if (fstatat(fd, d->d_name, &dst, flags) < 0) {
				if (!(r->flags & SILENT)) {
					weprintf("stat %s:", r->path);
					recurse_status = 1;
				}
			} else if ((r->flags & SAMEDEV) && dst.st_dev != st.st_dev) {
				continue;
			} else {
				r->depth++;
				r->fn(fd, d->d_name, &dst, data, r);
				r->depth--;
			}
		}
		r->path[pathlen - 1] = '\0';
		r->pathlen = pathlen - 1;
		closedir(dp);
	}

	if (!r->depth) {
		if (!(r->flags & DIRFIRST))
			r->fn(dirfd, name, &st, data, r);

		while (r->hist) {
			h = r->hist;
			r->hist = r->hist->prev;
			free(h);
		}
	}
}