/*-
 * Copyright (c) 2009-2010 Juan Romero Pardines.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <libgen.h>

#include <xbps_api.h>

int HIDDEN
xbps_remove_obsoletes(prop_dictionary_t oldd, prop_dictionary_t newd)
{
	prop_object_iterator_t iter, iter2 = NULL;
	prop_object_t obj, obj2 = NULL;
	prop_string_t oldstr = NULL, newstr = NULL;
	struct stat st;
	const char *array_str = "files";
	const char *oldhash = NULL;
	char *dname = NULL, *file = NULL;
	int rv = 0;
	bool found, dolinks = false;

again:
	iter = xbps_get_array_iter_from_dict(oldd, array_str);
	if (iter == NULL)
		return errno;
	iter2 = xbps_get_array_iter_from_dict(newd, array_str);
	if (iter2 == NULL) {
		prop_object_iterator_release(iter);
		return errno;
	}
	/*
	 * Check for obsolete files, i.e files/links available in
	 * the old package list not found in new package list.
	 */
	while ((obj = prop_object_iterator_next(iter))) {
		rv = 0;
		found = false;
		oldstr = prop_dictionary_get(obj, "file");
		if (oldstr == NULL) {
			rv = errno;
			goto out;
		}
		file = xbps_xasprintf(".%s",
		    prop_string_cstring_nocopy(oldstr));
		if (file == NULL) {
			rv = errno;
			goto out;
		}
		if (strcmp(array_str, "files") == 0) {
			prop_dictionary_get_cstring_nocopy(obj,
			    "sha256", &oldhash);
			rv = xbps_check_file_hash(file, oldhash);
			if (rv == ENOENT || rv == ERANGE) {
				/*
				 * Skip unexistent and files that do not
				 * match the hash.
				 */
				free(file);
				rv = 0;
				continue;
			}
		} else {
			/*
			 * Only remove dangling symlinks.
			 */
			if (stat(file, &st) == -1) {
				if (errno != ENOENT) {
					free(file);
					rv = errno;
					goto out;
				}
			} else {
				free(file);
				continue;
			}
		}

		while ((obj2 = prop_object_iterator_next(iter2))) {
			newstr = prop_dictionary_get(obj2, "file");
			if (newstr == NULL) {
				rv = errno;
				goto out;
			}
			if (prop_string_equals(oldstr, newstr)) {
				found = true;
				break;
			}
		}
		prop_object_iterator_reset(iter2);
		if (found) {
			free(file);
			continue;
		}

		/*
		 * Obsolete file found, remove it.
		 */
		if (remove(file) == -1) {
			fprintf(stderr,
			    "WARNING: couldn't remove obsolete %s: %s\n",
			    dolinks ? "link" : "file",
			    prop_string_cstring_nocopy(oldstr));
			free(file);
			continue;
		}
		printf("Removed obsolete %s: %s\n",
		    dolinks ? "link" : "file",
		    prop_string_cstring_nocopy(oldstr));
		/*
		 * Try to remove the directory where the obsole file or link
		 * was currently living on.
		 */
		dname = dirname(file);
		if (rmdir(dname) == -1) {
			if (errno != 0 && errno != EEXIST && errno != ENOTEMPTY)
				fprintf(stderr,
				    "WARNING: couldn't remove obsolete "
				    "directory %s: %s\n", dname,
				    strerror(errno));
		}
		free(file);
	}
	if (!dolinks) {
		/*
		 * Now look for obsolete links.
		 */
		dolinks = true;
		array_str = "links";
		prop_object_iterator_release(iter2);
		prop_object_iterator_release(iter);
		iter2 = NULL;
		goto again;
	}

out:
	prop_object_iterator_release(iter2);
	prop_object_iterator_release(iter);

	return rv;
}