/*

 * Copyright (C) 2008  Kristian Høgsberg <krh@redhat.com>

 * Copyright (C) 2008  Red Hat, Inc

 * Copyright (C) 2009  J. Ali Harlow <ali@juiblex.co.uk>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License along

 * with this program; if not, write to the Free Software Foundation, Inc.,

 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#define _GNU_SOURCE

#include "config.h"

#include <stdlib.h>

#include <stddef.h>

#include <stdint.h>

#include <stdio.h>

#include <stdarg.h>

#include <string.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <unistd.h>

#include <fcntl.h>

#include <errno.h>

#include <ctype.h>

#include <fnmatch.h>

#include <limits.h>

#include <assert.h>

#include "razor-internal.h"

#include "razor.h"

#ifndef O_BINARY

#define O_BINARY	0

#endif

void *

zalloc(size_t size)

{

	void *p;

	p = malloc(size);

	memset(p, 0, size);

	return p;

}

struct razor_set_section_index {

	const char *name;

	uint32_t offset;

};

struct razor_set_section_index razor_sections[] = {

	{ RAZOR_STRING_POOL,	offsetof(struct razor_set, string_pool) },

	{ RAZOR_PACKAGES,	offsetof(struct razor_set, packages) },

	{ RAZOR_PROPERTIES,	offsetof(struct razor_set, properties) },

	{ RAZOR_PACKAGE_POOL,	offsetof(struct razor_set, package_pool) },

	{ RAZOR_PROPERTY_POOL,	offsetof(struct razor_set, property_pool) },

	{ RAZOR_PREFIX_POOL,	offsetof(struct razor_set, prefix_pool) },

};

struct razor_set_section_index razor_files_sections[] = {

	{ RAZOR_FILES,			offsetof(struct razor_set, files) },

	{ RAZOR_FILE_POOL,		offsetof(struct razor_set, file_pool) },

	{ RAZOR_FILE_STRING_POOL,	offsetof(struct razor_set, file_string_pool) },

};

struct razor_set_section_index razor_details_sections[] = {

	{ RAZOR_DETAILS_STRING_POOL,	offsetof(struct razor_set, details_string_pool) },

};

RAZOR_EXPORT struct razor_set *

razor_set_create_without_root(void)

{

	struct razor_set *set;

	char *empty;

	set = zalloc(sizeof *set);

	empty = array_add(&set->string_pool, 1);

	*empty = '\0';

	return set;

}

RAZOR_EXPORT struct razor_set *

razor_set_create(void)

{

	struct razor_set *set;

	struct razor_entry *e;

	set = razor_set_create_without_root();

	e = array_add(&set->files, sizeof *e);

	e->name = 0;

	e->flags = RAZOR_ENTRY_LAST;

	e->start = 0;

	list_set_empty(&e->packages);

	return set;

}

static int

razor_set_bind_sections(struct razor_set *set,

			struct razor_set_header **header,

			size_t *header_size,

			struct razor_set_section_index section_index[],

			int section_index_size,

			const char *filename)

{

	struct razor_set_section *s, *sections;

	struct array *array;

	const char *pool;

	int i;

	*header = razor_file_get_contents(filename, header_size);

	if (!*header)

		return -1;

	sections = (void *) *header + sizeof **header;

	pool = (void *) sections + (*header)->num_sections * sizeof *sections;

	for (i = 0; i < (*header)->num_sections; i++) {

		int j;

		s = sections + i;

		for (j = 0; j < section_index_size; j++)

			if (!strcmp(section_index[j].name,

				    &pool[s->name]))

				break;

		if (j == section_index_size)

			continue;

		array = (void *) set + section_index[j].offset;

		array->data = (void *) *header + s->offset;

		array->size = s->size;

		array->alloc = s->size;

	}

	return 0;

}

RAZOR_EXPORT struct razor_set *

razor_set_open(const char *filename)

{

	struct razor_set *set;

	set = zalloc(sizeof *set);

	if (razor_set_bind_sections(set, &set->header, &set->header_size,

				    razor_sections, ARRAY_SIZE(razor_sections),

				    filename)){

		free(set);

		return NULL;

	}

	return set;

}

RAZOR_EXPORT int

razor_set_open_details(struct razor_set *set, const char *filename)

{

	return razor_set_bind_sections(set, &set->details_header,

				       &set->details_header_size,

				       razor_details_sections,

				       ARRAY_SIZE(razor_details_sections),

				       filename);

}

RAZOR_EXPORT int

razor_set_open_files(struct razor_set *set, const char *filename)

{

	return razor_set_bind_sections(set, &set->files_header,

				       &set->files_header_size,

				       razor_files_sections,

				       ARRAY_SIZE(razor_files_sections),

				       filename);

}

RAZOR_EXPORT void

razor_set_destroy(struct razor_set *set)

{

	struct array *a;

	int i;

	assert (set != NULL);

	if (set->header) {

		razor_file_free_contents(set->header, set->header_size);

	} else {

		for (i = 0; i < ARRAY_SIZE(razor_sections); i++) {

			a = (void *) set + razor_sections[i].offset;

			free(a->data);

		}

	}

	if (set->details_header) {

		razor_file_free_contents(set->details_header,

			set->details_header_size);

	} else {

		for (i = 0; i < ARRAY_SIZE(razor_details_sections); i++) {

			a = (void *) set + razor_details_sections[i].offset;

			free(a->data);

		}

	}

	if (set->files_header) {

		razor_file_free_contents(set->files_header,

			set->files_header_size);

	} else {

		for (i = 0; i < ARRAY_SIZE(razor_files_sections); i++) {

			a = (void *) set + razor_files_sections[i].offset;

			free(a->data);

		}

	}

	free(set);

}

static int

razor_set_write_sections_to_fd(struct razor_set *set, int fd,

			       struct razor_set_section_index *sections,

			       size_t array_size)

{

	struct razor_set_header header;

	struct razor_set_section *out_sections =

		malloc(array_size * sizeof *out_sections);

	struct hashtable table;

	struct array *a, pool;

	uint32_t offset;

	int i;

	header.magic = RAZOR_MAGIC;

	header.version = RAZOR_VERSION;

	header.num_sections = array_size;

	offset = sizeof header + array_size * sizeof *out_sections;

	array_init(&pool);

	hashtable_init(&table, &pool);

	for (i = 0; i < array_size; i++)

		out_sections[i].name =

			hashtable_tokenize(&table, sections[i].name);

	offset += pool.size;

	for (i = 0; i < array_size; i++) {

		a = (void *) set + sections[i].offset;

		out_sections[i].offset = offset;

		out_sections[i].size = a->size;

		offset += a->size;

	}

	razor_write(fd, &header, sizeof header);

	razor_write(fd, out_sections, array_size * sizeof *out_sections);

	razor_write(fd, pool.data, pool.size);

	for (i = 0; i < array_size; i++) {

		a = (void *) set + sections[i].offset;

		razor_write(fd, a->data, a->size);

	}

	free(out_sections);

	return 0;

}

RAZOR_EXPORT int

razor_set_write_to_fd(struct razor_set *set, int fd,

		      enum razor_repo_file_type type)

{

	switch (type) {

	case RAZOR_REPO_FILE_MAIN:

		return razor_set_write_sections_to_fd(set, fd,

						      razor_sections,

						      ARRAY_SIZE(razor_sections));

	case RAZOR_REPO_FILE_DETAILS:

		return razor_set_write_sections_to_fd(set, fd,

						      razor_details_sections,

						      ARRAY_SIZE(razor_details_sections));

	case RAZOR_REPO_FILE_FILES:

		return razor_set_write_sections_to_fd(set, fd,

						      razor_files_sections,

						      ARRAY_SIZE(razor_files_sections));

	default:

		return -1;

	}

}

RAZOR_EXPORT int

razor_set_write(struct razor_set *set, const char *filename,

		enum razor_repo_file_type type)

{

	int fd, status;

	fd = open(filename, O_CREAT | O_WRONLY | O_TRUNC | O_BINARY, 0666);

	if (fd < 0)

		return -1;

	status = razor_set_write_to_fd(set, fd, type);

	if (status) {

	    close(fd);

	    return status;

	}

	return close(fd);

}

RAZOR_EXPORT void

razor_build_evr(char *evr_buf, int size, const char *epoch,

		const char *version, const char *release)

{

	int len;

	if (!version || !*version) {

		*evr_buf = '\0';

		return;

	}

	if (epoch && *epoch && strcmp(epoch, "0") != 0) {

		len = snprintf(evr_buf, size, "%s:", epoch);

		evr_buf += len;

		size -= len;

	}

	len = snprintf(evr_buf, size, "%s", version);

	evr_buf += len;

	size -= len;

	if (release && *release)

		snprintf(evr_buf, size, "-%s", release);

}

RAZOR_EXPORT int

razor_versioncmp(const char *s1, const char *s2)

{

	const char *p1, *p2;

	long n1, n2;

	int res;

	assert (s1 != NULL);

	assert (s2 != NULL);

	n1 = strtol(s1, (char **) &p1, 10);

	n2 = strtol(s2, (char **) &p2, 10);

	/* Epoch; if one but not the other has an epoch set, default

	 * the epoch-less version to 0. */

	res = (*p1 == ':') - (*p2 == ':');

	if (res < 0) {

		n1 = 0;

		p1 = s1;

		p2++;

	} else if (res > 0) {

		p1++;

		n2 = 0;

		p2 = s2;

	}

	if (n1 != n2)

		return n1 - n2;

	while (*p1 && *p2) {

		if (*p1 != *p2)

			return *p1 - *p2;

		p1++;

		p2++;

		if (isdigit(*p1) && isdigit(*p2))

			return razor_versioncmp(p1, p2);

	}

	return *p1 - *p2;

}

static const char *

razor_package_get_details_string(struct razor_set *set,

				 struct razor_package *package,

				 enum razor_detail_type type)

{

	const char *pool;

	switch (type) {

	case RAZOR_DETAIL_NAME:

		pool = set->string_pool.data;

		return &pool[package->name];

	case RAZOR_DETAIL_VERSION:

		pool = set->string_pool.data;

		return &pool[package->version];

	case RAZOR_DETAIL_ARCH:

		pool = set->string_pool.data;

		return &pool[package->arch];

	case RAZOR_DETAIL_SUMMARY:

		pool = set->details_string_pool.data;

		return &pool[package->summary];

	case RAZOR_DETAIL_DESCRIPTION:

		pool = set->details_string_pool.data;

		return &pool[package->description];

	case RAZOR_DETAIL_URL:

		pool = set->details_string_pool.data;

		return &pool[package->url];

	case RAZOR_DETAIL_LICENSE:

		pool = set->details_string_pool.data;

		return &pool[package->license];

	case RAZOR_DETAIL_PREUNPROG:

		pool = set->string_pool.data;

		return &pool[package->preun.program];

	case RAZOR_DETAIL_PREUN:

		pool = set->string_pool.data;

		return &pool[package->preun.body];

	case RAZOR_DETAIL_POSTUNPROG:

		pool = set->string_pool.data;

		return &pool[package->postun.program];

	case RAZOR_DETAIL_POSTUN:

		pool = set->string_pool.data;

		return &pool[package->postun.body];

	default:

		fprintf(stderr, "type %u not found\n", type);

		return NULL;

	}

}

static const char *const *

razor_package_get_details_array(struct razor_set *set,

				struct razor_package *package,

				enum razor_detail_type type)

{

	switch (type) {

	case RAZOR_DETAIL_PREFIXES:

		/* We don't track prefixes in packages. Install prefixes

		 * are tracked, but we don't provide an API to get them.

		 */

		return NULL;

	default:

		fprintf(stderr, "type %u not found\n", type);

		return NULL;

	}

}

/**

 * razor_package_get_details_varg:

 * @set: a %razor_set

 * @package: a %razor_package

 * @args: a va_list of arguments to set

 **/

void

razor_package_get_details_varg(struct razor_set *set,

			       struct razor_package *package,

			       va_list args)

{

	int i;

	enum razor_detail_type type;

	const char **string;

	const char *const **array;

	for (i = 0;; i += 2) {

		type = va_arg(args, enum razor_detail_type);

		if (type == RAZOR_DETAIL_LAST)

			break;

		if (type == RAZOR_DETAIL_PREFIXES) {

			array = va_arg(args, const char *const **);

			*array = razor_package_get_details_array(set, package,

								 type);

		} else {

			string = va_arg(args, const char **);

			*string = razor_package_get_details_string(set, package,

								   type);

		}

	}

}

/**

 * razor_package_get_details:

 * @set: a %razor_set

 * @package: a %razor_package

 *

 * Gets details about a package using a varg interface

 * The vararg must be terminated with %RAZOR_DETAIL_LAST.

 *

 * Example: razor_package_get_details (set, package,

 *				       RAZOR_DETAIL_URL, &url,

 *				       RAZOR_DETAIL_LAST);

 **/

RAZOR_EXPORT void

razor_package_get_details(struct razor_set *set, struct razor_package *package, ...)

{

	va_list args;

	assert (set != NULL);

	assert (package != NULL);

	va_start(args, NULL);

	razor_package_get_details_varg (set, package, args);

	va_end (args);

}

/**

 * razor_package_remove:

 * @set: a %razor_set

 * @package: a %razor_package

 * @root: the root into which the package is currently installed

 *

 * Removes an installed package.

 **/

RAZOR_EXPORT int

razor_package_remove(struct razor_set *set, struct razor_package *package,

		     const char *root)

{

	struct razor_file_iterator *fi;

	struct razor_package_iterator *pi;

	struct razor_package *p;

	char buffer[PATH_MAX];

	const char *name, *program, *script;

	int retval = 0, i, count;

	struct environment env;

	struct list *link;

	const char *prefix;

	razor_package_get_details(set, package,

				  RAZOR_DETAIL_PREUNPROG, &program,

				  RAZOR_DETAIL_PREUN, &script,

				  RAZOR_DETAIL_LAST);

	if (razor_run_script(root, RAZOR_PROPERTY_PREUN, program, script))

		return -1;

	fi = razor_file_iterator_create(set, package);

	while (!retval && razor_file_iterator_next(fi, &name)) {

		pi = razor_package_iterator_create_for_file(set, name);

		count = 0;

		while (razor_package_iterator_next(pi, &p, RAZOR_DETAIL_LAST))

			count++;

		razor_package_iterator_destroy(pi);

		if (count <= 1) {

			snprintf(buffer, sizeof buffer, "%s%s", root, name);

			retval = remove(buffer);

		}

	}

	razor_file_iterator_destroy(fi);

	if (retval)

		return retval;

	razor_package_get_details(set, package,

				  RAZOR_DETAIL_POSTUNPROG, &program,

				  RAZOR_DETAIL_POSTUN, &script,

				  RAZOR_DETAIL_LAST);

	environment_init(&env);

	link = list_first(&package->install_prefixes, &set->prefix_pool);

	for (i = 0; link; i++) {

		prefix = (const char *)set->string_pool.data + link->data;

		sprintf(buffer, "RPM_INSTALL_PREFIX%d", i);

		environment_add_variable(&env, buffer, prefix);

		link = list_next(link);

	}

	environment_set(&env);

	retval = razor_run_script(root, RAZOR_PROPERTY_POSTUN, program, script);

	environment_unset(&env);

	environment_release(&env);

	return retval;

}

RAZOR_EXPORT const char *

razor_property_relation_to_string(struct razor_property *p)

{

	assert (p != NULL);

	switch (p->flags & RAZOR_PROPERTY_RELATION_MASK) {

	case RAZOR_PROPERTY_LESS:

		return "<";

	case RAZOR_PROPERTY_LESS | RAZOR_PROPERTY_EQUAL:

		return "<=";

	case RAZOR_PROPERTY_EQUAL:

		return "=";

	case RAZOR_PROPERTY_GREATER | RAZOR_PROPERTY_EQUAL:

		return ">=";

	case RAZOR_PROPERTY_GREATER:

		return ">";

	default:

		return "?";

	}

}

RAZOR_EXPORT const char *

razor_property_type_to_string(struct razor_property *p)

{

	assert (p != NULL);

	switch (p->flags & RAZOR_PROPERTY_TYPE_MASK) {

	case RAZOR_PROPERTY_REQUIRES:

		return "requires";

	case RAZOR_PROPERTY_PROVIDES:

		return "provides";

	case RAZOR_PROPERTY_CONFLICTS:

		return "conflicts";

	case RAZOR_PROPERTY_OBSOLETES:

		return "obsoletes";

	default:

		return NULL;

	}

}

RAZOR_EXPORT struct razor_entry *

razor_set_find_entry(struct razor_set *set,

		     struct razor_entry *dir, const char *pattern)

{

	struct razor_entry *e, *subdir;

	const char *n, *pool = set->file_string_pool.data;

	int len;

	assert (set != NULL);

	assert (dir != NULL);

	assert (pattern != NULL);

	e = dir;

	do {

		n = pool + e->name;

		if (strcmp(pattern, n) == 0)

			return e;

		len = strlen(n);

		if (e->start != 0 && strncmp(pattern, n, len) == 0 &&

		    pattern[len] == '/') {

			subdir = (struct razor_entry *) set->files.data +

				 e->start;

			return razor_set_find_entry(set, subdir,

						    pattern + len + 1);

		}

	} while (!((e++)->flags & RAZOR_ENTRY_LAST));

	return NULL;

}

static void

list_dir(struct razor_set *set, struct razor_entry *dir,

	 char *prefix, const char *pattern)

{

	struct razor_entry *e, *subdir;

	const char *n, *pool = set->file_string_pool.data;

	e = dir;

	do {

		n = pool + e->name;

		if (pattern && pattern[0] && fnmatch(pattern, n, 0) != 0)

			continue;

		printf("%s/%s\n", prefix, n);

		if (e->start) {

			char *sub = prefix + strlen (prefix);

			*sub = '/';

			strcpy (sub + 1, n);

			subdir = (struct razor_entry *) set->files.data +

				 e->start;

			list_dir(set, subdir, prefix, pattern);

			*sub = '\0';

		}

	} while (!((e++)->flags & RAZOR_ENTRY_LAST));

}

RAZOR_EXPORT void

razor_set_list_files(struct razor_set *set, const char *pattern)

{

	struct razor_entry *root, *e;

	char buffer[512], *p, *base;

	assert (set != NULL);

	root = (struct razor_entry *) set->files.data;

	if (pattern == NULL) {

		p = set->file_string_pool.data;

		e = root;

		do {

			if (e->start) {

				strcpy(buffer, p + e->name);

				list_dir(set, root + e->start, buffer, NULL);

			}

		} while (!((e++)->flags & RAZOR_ENTRY_LAST));

		return;

	}

	strcpy(buffer, pattern);

	e = razor_set_find_entry(set, root, buffer);

	if (e && e->start) {

		base = NULL;

	} else {

		p = strrchr(buffer, '/');

		if (p) {

			*p = '\0';

			base = p + 1;

		} else {

			base = NULL;

		}

	}

	e = razor_set_find_entry(set, root, buffer);

	if (e && e->start)

		list_dir(set, root + e->start, buffer, base);

}

RAZOR_EXPORT void

razor_set_list_package_files(struct razor_set *set,

			     struct razor_package *package)

{

	struct razor_file_iterator *fi;

	const char *name;

	assert (set != NULL);

	assert (package != NULL);

	fi = razor_file_iterator_create(set, package);

	while (razor_file_iterator_next(fi, &name))

		printf("%s\n", name);

	razor_file_iterator_destroy(fi);

}

RAZOR_EXPORT void

razor_set_diff(struct razor_set *set, struct razor_set *upstream,

	       razor_diff_callback_t callback, void *data)

{

 	struct razor_package_iterator *pi1, *pi2;

 	struct razor_package *p1, *p2;

	const char *name1, *name2, *version1, *version2, *arch1, *arch2;

	int res;

	assert (set != NULL);

	assert (upstream != NULL);

	pi1 = razor_package_iterator_create(set);

	pi2 = razor_package_iterator_create(upstream);

	razor_package_iterator_next(pi1, &p1,

				    RAZOR_DETAIL_NAME, &name1,

				    RAZOR_DETAIL_VERSION, &version1,

				    RAZOR_DETAIL_ARCH, &arch1,

				    RAZOR_DETAIL_LAST);

	razor_package_iterator_next(pi2, &p2,

				    RAZOR_DETAIL_NAME, &name2,

				    RAZOR_DETAIL_VERSION, &version2,

				    RAZOR_DETAIL_ARCH, &arch2,

				    RAZOR_DETAIL_LAST);

	while (p1 || p2) {

		if (p1 && p2) {

			res = strcmp(name1, name2);

			if (res == 0)

				res = razor_versioncmp(version1, version2);

		} else {

			res = 0;

		}

		if (p2 == NULL || res < 0)

			callback(RAZOR_DIFF_ACTION_REMOVE,

				 p1, name1, version1, arch1, data);

		else if (p1 == NULL || res > 0)

			callback(RAZOR_DIFF_ACTION_ADD,

				 p2, name2, version2, arch2, data);

		if (p1 != NULL && res <= 0)

			razor_package_iterator_next(pi1, &p1,

						    RAZOR_DETAIL_NAME, &name1,

						    RAZOR_DETAIL_VERSION, &version1,

						    RAZOR_DETAIL_ARCH, &arch1,

						    RAZOR_DETAIL_LAST);

		if (p2 != NULL && res >= 0)

			razor_package_iterator_next(pi2, &p2,

						    RAZOR_DETAIL_NAME, &name2,

						    RAZOR_DETAIL_VERSION, &version2,

						    RAZOR_DETAIL_ARCH, &arch2,

						    RAZOR_DETAIL_LAST);

	}

	razor_package_iterator_destroy(pi1);

	razor_package_iterator_destroy(pi2);

}

struct install_action {

	enum razor_install_action action;

	struct razor_package *package;

};

struct razor_install_iterator {

	struct razor_set *set;

	struct razor_set *next;

	struct array actions;

	struct deque *order;

};

static void

add_action(enum razor_diff_action action,

	   struct razor_package *package,

	   const char *name,

	   const char *version,

	   const char *arch,

	   void *data)

{

	struct razor_install_iterator *ii = data;

	struct install_action *a;

	a = array_add(&ii->actions, sizeof *a);

	a->package = package;

	switch (action) {

	case RAZOR_DIFF_ACTION_ADD:

		a->action = RAZOR_INSTALL_ACTION_ADD;

		break;

	case RAZOR_DIFF_ACTION_REMOVE:

		a->action = RAZOR_INSTALL_ACTION_REMOVE;

		break;

	}

}

RAZOR_EXPORT struct razor_install_iterator *

razor_set_create_install_iterator(struct razor_set *set,

				  struct razor_set *next)

{

	struct razor_install_iterator *ii;

	struct razor_property *prop;

	/* A graph of the actions to be perfomed where

	 * A->B means action A should follow action B.

	 */

	struct graph follows;

	struct install_action *actions, *ai, *aj;

	int i, j, count, vertex_added;

	struct list *link;

	struct razor_set *rs;

	assert (set != NULL);

	assert (next != NULL);

	ii = zalloc(sizeof *ii);

	ii->set = set;

	ii->next = next;

	razor_set_diff(set, next, add_action, ii);

	actions = ii->actions.data;

	count = ii->actions.size / sizeof (struct install_action);

	graph_init(&follows);

	for(i = 0; i < count; i++) {

		ai = actions + i;

		rs = ai->action == RAZOR_INSTALL_ACTION_ADD ? next : set;

		vertex_added = 0;

		link = list_first(&ai->package->properties, &rs->property_pool);

		for(; link; link = list_next(link)) {

			prop = rs->properties.data;

			prop += link->data;

			switch(prop->flags & RAZOR_PROPERTY_TYPE_MASK) {

			case RAZOR_PROPERTY_REQUIRES:

			case RAZOR_PROPERTY_CONFLICTS:

				for(j = 0; j < count; j++) {

					if (j == i)

						continue;

					aj = actions + j;

					if (aj->package->name == prop->name) {

						if (ai->action ==

						    RAZOR_INSTALL_ACTION_ADD)

							graph_add_edge(&follows,

								       i, j);

						else

							graph_add_edge(&follows,

								       j, i);

						vertex_added++;

					}

				}

				break;

			}

		}

		if (ai->action == RAZOR_INSTALL_ACTION_ADD) {

			for(j = 0; j < count; j++) {

				if (j == i)

					continue;

				aj = actions + j;

				if (aj->package == ai->package &&

				    aj->action == RAZOR_INSTALL_ACTION_REMOVE) {

					graph_add_edge(&follows, i, j);

					vertex_added++;

				}

			}

		}

		if (!vertex_added)

			graph_add_edge(&follows, i, i);

	}

	ii->order = graph_sort(&follows);

	graph_release(&follows);

	return ii;

}

RAZOR_EXPORT int

razor_install_iterator_next(struct razor_install_iterator *ii,

			    struct razor_set **set,

			    struct razor_package **package,

			    enum razor_install_action *action,

			    int *count)

{

	struct install_action *a;

	if (deque_empty(ii->order))

		return 0;

	a = (struct install_action *)ii->actions.data + deque_pop(ii->order);

	switch (a->action) {

	case RAZOR_INSTALL_ACTION_ADD:

		*set = ii->next;

		break;

	case RAZOR_INSTALL_ACTION_REMOVE:

		*set = ii->set;

		break;

	}

	*package = a->package;

	*action = a->action;

	*count = 0;

	return 1;

}

RAZOR_EXPORT void

razor_install_iterator_destroy(struct razor_install_iterator *ii)

{

	array_release(&ii->actions);

	deque_free(ii->order);

	free(ii);

}