/*
 *  sync.c
 *
 *  Copyright (c) 2002-2007 by Judd Vinet <jvinet@zeroflux.org>
 *  Copyright (c) 2005 by Aurelien Foret <orelien@chez.com>
 *  Copyright (c) 2005 by Christian Hamar <krics@linuxforum.hu>
 *  Copyright (c) 2005, 2006 by Miklos Vajna <vmiklos@frugalware.org>
 *
 *  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, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <dirent.h>

/* libalpm */
#include "sync.h"
#include "alpm_list.h"
#include "log.h"
#include "error.h"
#include "package.h"
#include "db.h"
#include "cache.h"
#include "deps.h"
#include "conflict.h"
#include "trans.h"
#include "util.h"
#include "handle.h"
#include "alpm.h"
#include "server.h"
#include "dload.h"
#include "delta.h"

pmsyncpkg_t *_alpm_sync_new(pmpkgreason_t newreason, pmpkg_t *spkg, alpm_list_t *removes)
{
	pmsyncpkg_t *sync;

	ALPM_LOG_FUNC;

	CALLOC(sync, 1, sizeof(pmsyncpkg_t), RET_ERR(PM_ERR_MEMORY, NULL));

	sync->newreason = newreason;
	sync->pkg = spkg;
	sync->removes = removes;

	return(sync);
}

void _alpm_sync_free(pmsyncpkg_t *sync)
{
	ALPM_LOG_FUNC;

	if(sync == NULL) {
		return;
	}

	alpm_list_free(sync->removes);
	sync->removes = NULL;
	FREE(sync);
}

/* Find recommended replacements for packages during a sync.
 */
static int find_replacements(pmtrans_t *trans, pmdb_t *db_local,
		alpm_list_t *dbs_sync, alpm_list_t **syncpkgs)
{
	alpm_list_t *i, *j, *k; /* wow */

	ALPM_LOG_FUNC;

	if(syncpkgs == NULL) {
		return(-1);
	}

	/* check for "recommended" package replacements */
	_alpm_log(PM_LOG_DEBUG, "checking for package replacements\n");
	for(i = dbs_sync; i; i = i->next) {
		pmdb_t *db = i->data;

		/* for each db, check each package's REPLACES list */
		for(j = _alpm_db_get_pkgcache(db); j; j = j->next) {
			pmpkg_t *spkg = j->data;

			for(k = alpm_pkg_get_replaces(spkg); k; k = k->next) {
				const char *replacement = k->data;

				pmpkg_t *lpkg = _alpm_db_get_pkgfromcache(db_local, replacement);
				if(!lpkg) {
					continue;
				}

				_alpm_log(PM_LOG_DEBUG, "checking replacement '%s' for package '%s'\n",
						replacement, spkg->name);
				/* ignore if EITHER the local or replacement package are to be ignored */
				if(_alpm_pkg_should_ignore(spkg) || _alpm_pkg_should_ignore(lpkg)) {
					_alpm_log(PM_LOG_WARNING, _("%s-%s: ignoring package upgrade (to be replaced by %s-%s)\n"),
										alpm_pkg_get_name(lpkg), alpm_pkg_get_version(lpkg),
										alpm_pkg_get_name(spkg), alpm_pkg_get_version(spkg));
				} else {
					/* get confirmation for the replacement */
					if(trans) {
						int doreplace = 0;
						QUESTION(trans, PM_TRANS_CONV_REPLACE_PKG, lpkg, spkg, db->treename, &doreplace);
						if(!doreplace) {
							continue;
						}
					}

					/* if confirmed, add this to the 'final' list, designating 'lpkg' as
					 * the package to replace.
					 */
					pmsyncpkg_t *sync;

					/* check if spkg->name is already in the packages list. */
					sync = _alpm_sync_find(*syncpkgs, alpm_pkg_get_name(spkg));
					if(sync) {
						/* found it -- just append to the removes list */
						sync->removes = alpm_list_add(sync->removes, lpkg);
						/* check the to-be-replaced package's reason field */
						if(lpkg->reason == PM_PKG_REASON_EXPLICIT) {
							sync->newreason = PM_PKG_REASON_EXPLICIT;
						}
					} else {
						/* none found -- enter pkg into the final sync list */
						/* copy over reason */
						sync = _alpm_sync_new(alpm_pkg_get_reason(lpkg), spkg, NULL);
						if(sync == NULL) {
							pm_errno = PM_ERR_MEMORY;
							alpm_list_free_inner(*syncpkgs, (alpm_list_fn_free)_alpm_sync_free);
							alpm_list_free(*syncpkgs);
							*syncpkgs = NULL;
							return(-1);
						}
						sync->removes = alpm_list_add(NULL, lpkg);
						*syncpkgs = alpm_list_add(*syncpkgs, sync);
					}
					_alpm_log(PM_LOG_DEBUG, "%s-%s elected for upgrade (to be replaced by %s-%s)\n",
							alpm_pkg_get_name(lpkg), alpm_pkg_get_version(lpkg),
							alpm_pkg_get_name(spkg), alpm_pkg_get_version(spkg));
				}
			}
		}
	}
	return(0);
}

/** Check for new version of pkg in sync repos
 * (only the first occurrence is considered in sync)
 */
pmpkg_t SYMEXPORT *alpm_sync_newversion(pmpkg_t *pkg, alpm_list_t *dbs_sync)
{
	alpm_list_t *i;
	pmpkg_t *spkg = NULL;

	for(i = dbs_sync; !spkg && i; i = i->next) {
		spkg = _alpm_db_get_pkgfromcache(i->data, alpm_pkg_get_name(pkg));
	}

	if(spkg == NULL) {
		_alpm_log(PM_LOG_DEBUG, "'%s' not found in sync db => no upgrade\n",
				alpm_pkg_get_name(pkg));
		return(NULL);
	}

	/* compare versions and see if spkg is an upgrade */
	if(_alpm_pkg_compare_versions(pkg, spkg)) {
		_alpm_log(PM_LOG_DEBUG, "new version of '%s' found (%s => %s)\n",
					alpm_pkg_get_name(pkg), alpm_pkg_get_version(pkg),
					alpm_pkg_get_version(spkg));
		return(spkg);
	} else {
		return(NULL);
	}
}

/** Get a list of upgradable packages on the current system
 * Adds out of date packages to *list.
 * @arg list pointer to a list of pmsyncpkg_t.
 */
int SYMEXPORT alpm_sync_sysupgrade(pmdb_t *db_local,
		alpm_list_t *dbs_sync, alpm_list_t **syncpkgs)
{
	return(_alpm_sync_sysupgrade(NULL, db_local, dbs_sync, syncpkgs));
}

int _alpm_sync_sysupgrade(pmtrans_t *trans,
		pmdb_t *db_local, alpm_list_t *dbs_sync, alpm_list_t **syncpkgs)
{
	alpm_list_t *i, *j, *replaced = NULL;

	ALPM_LOG_FUNC;

	if(syncpkgs == NULL) {
		return(-1);
	}
	/* check for "recommended" package replacements */
	if(find_replacements(trans, db_local, dbs_sync, syncpkgs)) {
		return(-1);
	}

	/* compute the to-be-replaced packages for efficiency */
	for(i = *syncpkgs; i; i = i->next) {
		pmsyncpkg_t *sync = i->data;
		for(j = sync->removes; j; j = j->next) {
			replaced = alpm_list_add(replaced, j->data);
		}
	}

	/* for all not-replaced local package we check for upgrade */
	_alpm_log(PM_LOG_DEBUG, "checking for package upgrades\n");
	for(i = _alpm_db_get_pkgcache(db_local); i; i = i->next) {
		pmpkg_t *local = i->data;

		if(_alpm_pkg_find(alpm_pkg_get_name(local), replaced)) {
			_alpm_log(PM_LOG_DEBUG, "'%s' is already elected for removal -- skipping\n",
					alpm_pkg_get_name(local));
			continue;
		}

		pmpkg_t *spkg = alpm_sync_newversion(local, dbs_sync);
		if(spkg) {
			/* we found a new version */
			/* skip packages in IgnorePkg or in IgnoreGroup */
			if(_alpm_pkg_should_ignore(spkg)) {
				_alpm_log(PM_LOG_WARNING, _("%s: ignoring package upgrade (%s => %s)\n"),
						alpm_pkg_get_name(local), alpm_pkg_get_version(local),
						alpm_pkg_get_version(spkg));
				continue;
			}

			/* add the upgrade package to our pmsyncpkg_t list */
			if(_alpm_sync_find(*syncpkgs, alpm_pkg_get_name(spkg))) {
				/* it is already there, done */
				continue;
			}
			/* we can set any reason here, it will be overridden by add_commit */
			pmsyncpkg_t *sync = _alpm_sync_new(PM_PKG_REASON_EXPLICIT, spkg, NULL);
			if(sync == NULL) {
				alpm_list_free_inner(*syncpkgs, (alpm_list_fn_free)_alpm_sync_free);
				alpm_list_free(*syncpkgs);
				*syncpkgs = NULL;
				alpm_list_free(replaced);
				return(-1);
			}
			*syncpkgs = alpm_list_add(*syncpkgs, sync);
		}
	}

	alpm_list_free(replaced);
	return(0);
}

int _alpm_sync_addtarget(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_sync, char *name)
{
	char *targline;
	char *targ;
	alpm_list_t *j;
	pmpkg_t *local;
	pmpkg_t *spkg = NULL;
	pmsyncpkg_t *sync;
	int repo_found = 0;

	ALPM_LOG_FUNC;

	ASSERT(db_local != NULL, RET_ERR(PM_ERR_DB_NULL, -1));
	ASSERT(trans != NULL, RET_ERR(PM_ERR_TRANS_NULL, -1));
	ASSERT(name != NULL, RET_ERR(PM_ERR_WRONG_ARGS, -1));
	STRDUP(targline, name, RET_ERR(PM_ERR_MEMORY, -1));

	targ = strchr(targline, '/');
	if(targ) {
		/* we are looking for a package in a specific database */
		*targ = '\0';
		targ++;
		_alpm_log(PM_LOG_DEBUG, "searching for target '%s' in repo\n", targ);
		for(j = dbs_sync; j && !spkg; j = j->next) {
			pmdb_t *db = j->data;
			if(strcmp(db->treename, targline) == 0) {
				repo_found = 1;
				spkg = _alpm_db_get_pkgfromcache(db, targ);
				if(spkg == NULL) {
					pm_errno = PM_ERR_PKG_NOT_FOUND;
					goto error;
				}
			}
		}
		if(!repo_found) {
			_alpm_log(PM_LOG_ERROR, _("repository '%s' not found\n"), targline);
			pm_errno = PM_ERR_PKG_REPO_NOT_FOUND;
			goto error;
		}
	} else {
		targ = targline;
		for(j = dbs_sync; j && !spkg; j = j->next) {
			pmdb_t *db = j->data;
			spkg = _alpm_db_get_pkgfromcache(db, targ);
		}
		if(spkg == NULL) {
			pm_errno = PM_ERR_PKG_NOT_FOUND;
			goto error;
		}
	}

	if(_alpm_pkg_should_ignore(spkg)) {
		int resp;
		QUESTION(trans, PM_TRANS_CONV_INSTALL_IGNOREPKG, spkg, NULL, NULL, &resp);
		if (!resp) {
			return(0);
		}
	}

	local = _alpm_db_get_pkgfromcache(db_local, alpm_pkg_get_name(spkg));
	if(local) {
		if(_alpm_pkg_compare_versions(local, spkg) == 0) {
			/* spkg is NOT an upgrade */
			if(trans->flags & PM_TRANS_FLAG_NEEDED) {
				_alpm_log(PM_LOG_WARNING, _("%s-%s is up to date -- skipping\n"),
						alpm_pkg_get_name(local), alpm_pkg_get_version(local));
				return(0);
			} else {
				if(!(trans->flags & PM_TRANS_FLAG_DOWNLOADONLY)) {
					_alpm_log(PM_LOG_WARNING, _("%s-%s is up to date -- reinstalling\n"),
							alpm_pkg_get_name(local), alpm_pkg_get_version(local));
				}
			}
		}
	}

	/* add the package to the transaction */
	if(!_alpm_sync_find(trans->packages, alpm_pkg_get_name(spkg))) {
		sync = _alpm_sync_new(PM_PKG_REASON_EXPLICIT, spkg, NULL);
		if(sync == NULL) {
			goto error;
		}
		_alpm_log(PM_LOG_DEBUG, "adding target '%s' to the transaction set\n",
							alpm_pkg_get_name(spkg));
		trans->packages = alpm_list_add(trans->packages, sync);
	}

	FREE(targline);
	return(0);

error:
	if(targline) {
		FREE(targline);
	}
	return(-1);
}

/* Helper functions for alpm_list_remove
*/
static int syncpkg_cmp(const void *s1, const void *s2)
{
	const pmsyncpkg_t *sp1 = s1;
	const pmsyncpkg_t *sp2 = s2;
	pmpkg_t *p1, *p2;

	p1 = alpm_sync_get_pkg(sp1);
	p2 = alpm_sync_get_pkg(sp2);

	return(strcmp(alpm_pkg_get_name(p1), alpm_pkg_get_name(p2)));
}

int _alpm_sync_prepare(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_sync, alpm_list_t **data)
{
	alpm_list_t *deps = NULL;
	alpm_list_t *list = NULL, *remove = NULL; /* allow checkdeps usage with trans->packages */
	alpm_list_t *i, *j;
	int ret = 0;

	ALPM_LOG_FUNC;

	ASSERT(db_local != NULL, RET_ERR(PM_ERR_DB_NULL, -1));
	ASSERT(trans != NULL, RET_ERR(PM_ERR_TRANS_NULL, -1));

	if(data) {
		*data = NULL;
	}

	if(!(trans->flags & PM_TRANS_FLAG_DEPENDSONLY)) {
		for(i = trans->packages; i; i = i->next) {
			pmsyncpkg_t *sync = i->data;
			list = alpm_list_add(list, sync->pkg);
		}
	}

	if(!(trans->flags & PM_TRANS_FLAG_NODEPS)) {
		/* Resolve targets dependencies */
		EVENT(trans, PM_TRANS_EVT_RESOLVEDEPS_START, NULL, NULL);
		_alpm_log(PM_LOG_DEBUG, "resolving target's dependencies\n");

		/* build remove list for resolvedeps */
		for(i = trans->packages; i; i = i->next) {
			pmsyncpkg_t *sync = i->data;
			for(j = sync->removes; j; j = j->next) {
				remove = alpm_list_add(remove, j->data);
			}
		}

		for(i = trans->packages; i; i = i->next) {
			pmpkg_t *spkg = ((pmsyncpkg_t *)i->data)->pkg;
			if(_alpm_resolvedeps(db_local, dbs_sync, spkg, &list,
						remove, trans, data) == -1) {
				/* pm_errno is set by resolvedeps */
				ret = -1;
				goto cleanup;
			}
		}

		if((trans->flags & PM_TRANS_FLAG_DEPENDSONLY)) {
			FREELIST(trans->packages);
		}

		for(i = list; i; i = i->next) {
			/* add the dependencies found by resolvedeps to the transaction set */
			pmpkg_t *spkg = i->data;
			if(!_alpm_sync_find(trans->packages, alpm_pkg_get_name(spkg))) {
				pmsyncpkg_t *sync = _alpm_sync_new(PM_PKG_REASON_DEPEND, spkg, NULL);
				if(sync == NULL) {
					ret = -1;
					goto cleanup;
				}
				trans->packages = alpm_list_add(trans->packages, sync);
				_alpm_log(PM_LOG_DEBUG, "adding package %s-%s to the transaction targets\n",
									alpm_pkg_get_name(spkg), alpm_pkg_get_version(spkg));
			}
		}

		/* re-order w.r.t. dependencies */
		alpm_list_t *sortlist = _alpm_sortbydeps(list, PM_TRANS_TYPE_ADD);
		alpm_list_t *newpkgs = NULL;
		for(i = sortlist; i; i = i->next) {
			for(j = trans->packages; j; j = j->next) {
				pmsyncpkg_t *s = j->data;
				if(s->pkg == i->data) {
					newpkgs = alpm_list_add(newpkgs, s);
				}
			}
		}
		alpm_list_free(sortlist);
		alpm_list_free(trans->packages);
		trans->packages = newpkgs;

		EVENT(trans, PM_TRANS_EVT_RESOLVEDEPS_DONE, NULL, NULL);
	}

	/* We don't care about conflicts if we're just printing uris */
	if(!(trans->flags & (PM_TRANS_FLAG_NOCONFLICTS | PM_TRANS_FLAG_PRINTURIS))) {
		/* check for inter-conflicts and whatnot */
		EVENT(trans, PM_TRANS_EVT_INTERCONFLICTS_START, NULL, NULL);

		_alpm_log(PM_LOG_DEBUG, "looking for conflicts\n");

		/* 1. check for conflicts in the target list */
		_alpm_log(PM_LOG_DEBUG, "check targets vs targets\n");
		deps = _alpm_innerconflicts(list);

		for(i = deps; i; i = i->next) {
			pmconflict_t *conflict = i->data;
			pmsyncpkg_t *rsync, *sync, *sync1, *sync2;

			/* have we already removed one of the conflicting targets? */
			sync1 = _alpm_sync_find(trans->packages, conflict->package1);
			sync2 = _alpm_sync_find(trans->packages, conflict->package2);
			if(!sync1 || !sync2) {
				continue;
			}

			_alpm_log(PM_LOG_DEBUG, "conflicting packages in the sync list: '%s' <-> '%s'\n",
					conflict->package1, conflict->package2);

			/* if sync1 provides sync2, we remove sync2 from the targets, and vice versa */
			if(alpm_list_find(alpm_pkg_get_provides(sync1->pkg),
						conflict->package2, _alpm_prov_cmp)) {
				rsync = sync2;
				sync = sync1;
			} else if(alpm_list_find(alpm_pkg_get_provides(sync2->pkg),
						conflict->package1, _alpm_prov_cmp)) {
				rsync = sync1;
				sync = sync2;
			} else {
				_alpm_log(PM_LOG_ERROR, _("unresolvable package conflicts detected\n"));
				pm_errno = PM_ERR_CONFLICTING_DEPS;
				ret = -1;
				if(data) {
					pmconflict_t *newconflict = _alpm_conflict_dup(conflict);
					if(newconflict) {
						*data = alpm_list_add(*data, newconflict);
					}
				}
				alpm_list_free_inner(deps, (alpm_list_fn_free)_alpm_conflict_free);
				alpm_list_free(deps);
				goto cleanup;
			}

			_alpm_log(PM_LOG_DEBUG, "removing '%s' from target list\n", rsync->pkg->name);
			/* Only prints a warning if rsync is an explicit target. */
			if(alpm_list_find_str(trans->targets, rsync->pkg->name)) {
				_alpm_log(PM_LOG_WARNING,
						_("removing '%s' from target list because it conflicts with '%s'\n"),
						rsync->pkg->name, sync->pkg->name);
			}
			void *vpkg;
			trans->packages = alpm_list_remove(trans->packages, rsync,
					syncpkg_cmp, &vpkg);
			pmsyncpkg_t *syncpkg = vpkg;
			list = alpm_list_remove(list, syncpkg->pkg, _alpm_pkg_cmp, NULL);
			_alpm_sync_free(syncpkg);
			continue;
		}

		alpm_list_free_inner(deps, (alpm_list_fn_free)_alpm_conflict_free);
		alpm_list_free(deps);
		deps = NULL;

		/* 2. we check for target vs db conflicts (and resolve)*/
		_alpm_log(PM_LOG_DEBUG, "check targets vs db and db vs targets\n");
		deps = _alpm_outerconflicts(db_local, list);

		for(i = deps; i; i = i->next) {
			pmconflict_t *conflict = i->data;

			/* if conflict->package2 (the local package) is not elected for removal,
			   we ask the user */
			int found = 0;
			for(j = trans->packages; j && !found; j = j->next) {
				pmsyncpkg_t *sync = j->data;
				if(_alpm_pkg_find(conflict->package2, sync->removes)) {
					found = 1;
				}
			}
			if(found) {
				continue;
			}

			_alpm_log(PM_LOG_DEBUG, "package '%s' conflicts with '%s'\n",
					conflict->package1, conflict->package2);

			pmsyncpkg_t *sync = _alpm_sync_find(trans->packages, conflict->package1);
			pmpkg_t *local = _alpm_db_get_pkgfromcache(db_local, conflict->package2);
			int doremove = 0;
			QUESTION(trans, PM_TRANS_CONV_CONFLICT_PKG, conflict->package1,
								conflict->package2, NULL, &doremove);
			if(doremove) {
				/* append to the removes list */
				_alpm_log(PM_LOG_DEBUG, "electing '%s' for removal\n", conflict->package2);
				sync->removes = alpm_list_add(sync->removes, local);
			} else { /* abort */
				_alpm_log(PM_LOG_ERROR, _("unresolvable package conflicts detected\n"));
				pm_errno = PM_ERR_CONFLICTING_DEPS;
				ret = -1;
				if(data) {
					pmconflict_t *newconflict = _alpm_conflict_dup(conflict);
					if(newconflict) {
						*data = alpm_list_add(*data, newconflict);
					}
				}
				alpm_list_free_inner(deps, (alpm_list_fn_free)_alpm_conflict_free);
				alpm_list_free(deps);
				goto cleanup;
			}
		}
		EVENT(trans, PM_TRANS_EVT_INTERCONFLICTS_DONE, NULL, NULL);
		alpm_list_free_inner(deps, (alpm_list_fn_free)_alpm_conflict_free);
		alpm_list_free(deps);
	}

	if(!(trans->flags & PM_TRANS_FLAG_NODEPS)) {
		/* rebuild remove list */
		alpm_list_free(remove);
		remove = NULL;
		for(i = trans->packages; i; i = i->next) {
			pmsyncpkg_t *sync = i->data;
			for(j = sync->removes; j; j = j->next) {
				remove = alpm_list_add(remove, j->data);
			}
		}

		_alpm_log(PM_LOG_DEBUG, "checking dependencies\n");
		deps = alpm_checkdeps(db_local, 1, remove, list);
		if(deps) {
			pm_errno = PM_ERR_UNSATISFIED_DEPS;
			ret = -1;
			if(data) {
				*data = deps;
			} else {
				alpm_list_free_inner(deps, (alpm_list_fn_free)_alpm_depmiss_free);
				alpm_list_free(deps);
			}
			goto cleanup;
		}
	}

cleanup:
	alpm_list_free(list);
	alpm_list_free(remove);

	return(ret);
}

/** Returns a list of deltas that should be downloaded instead of the
 * package.
 *
 * It first tests if a delta path exists between the currently installed
 * version (if any) and the version to upgrade to. If so, the delta path
 * is used if its size is below a set percentage (MAX_DELTA_RATIO) of
 * the package size, Otherwise, an empty list is returned.
 *
 * @param newpkg the new package to upgrade to
 * @param db_local the local database
 *
 * @return the list of pmdelta_t * objects. NULL (the empty list) is
 * returned if the package should be downloaded instead of deltas.
 */
static alpm_list_t *pkg_upgrade_delta_path(pmpkg_t *newpkg, pmdb_t *db_local)
{
	pmpkg_t *oldpkg = alpm_db_get_pkg(db_local, newpkg->name);
	alpm_list_t *ret = NULL;

	if(oldpkg) {
		const char *oldname = alpm_pkg_get_filename(oldpkg);
		char *oldpath = _alpm_filecache_find(oldname);

		if(oldpath) {
			alpm_list_t *deltas = _alpm_shortest_delta_path(
					alpm_pkg_get_deltas(newpkg),
					alpm_pkg_get_version(oldpkg),
					alpm_pkg_get_version(newpkg));

			if(deltas) {
				unsigned long dltsize = _alpm_delta_path_size(deltas);
				unsigned long pkgsize = alpm_pkg_get_size(newpkg);

				if(dltsize < pkgsize * MAX_DELTA_RATIO) {
					ret = deltas;
				} else {
					ret = NULL;
					alpm_list_free(deltas);
				}
			}

			FREE(oldpath);
		}
	}

	return(ret);
}

/** Returns the size of the files that will be downloaded to install a
 * package.
 *
 * @param newpkg the new package to upgrade to
 * @param db_local the local database
 *
 * @return the size of the download
 */
unsigned long SYMEXPORT alpm_pkg_download_size(pmpkg_t *newpkg, pmdb_t *db_local)
{
	char *fpath = _alpm_filecache_find(alpm_pkg_get_filename(newpkg));
	unsigned long size = 0;

	if(fpath) {
		size = 0;
	} else if(handle->usedelta) {
		alpm_list_t *deltas = pkg_upgrade_delta_path(newpkg, db_local);

		if(deltas) {
			size = _alpm_delta_path_size_uncached(deltas);
		} else {
			size = alpm_pkg_get_size(newpkg);
		}

		alpm_list_free(deltas);
	} else {
		size = alpm_pkg_get_size(newpkg);
	}

	FREE(fpath);

	return(size);
}

/** Applies delta files to create an upgraded package file.
 *
 * All intermediate files are deleted, leaving only the starting and
 * ending package files.
 *
 * @param trans the transaction
 * @param patches A list of alternating pmpkg_t * and pmdelta_t *
 * objects. The patch command will be built using the pmpkg_t, pmdelta_t
 * pair.
 *
 * @return 0 if all delta files were able to be applied, 1 otherwise.
 */
static int apply_deltas(pmtrans_t *trans, alpm_list_t *patches)
{
	/* keep track of the previous package in the loop to decide if a
	 * package file should be deleted */
	pmpkg_t *lastpkg = NULL;
	int lastpkg_failed = 0;
	int ret = 0;
	const char *cachedir = _alpm_filecache_setup();

	alpm_list_t *p = patches;
	while(p) {
		pmpkg_t *pkg;
		pmdelta_t *d;
		char command[PATH_MAX], fname[PATH_MAX];
		char pkgfilename[PATH_MAX];

		pkg = alpm_list_getdata(p);
		p = alpm_list_next(p);

		d = alpm_list_getdata(p);
		p = alpm_list_next(p);

		/* if patching fails, ignore the rest of that package's deltas */
		if(lastpkg_failed) {
			if(pkg == lastpkg) {
				continue;
			} else {
				lastpkg_failed = 0;
			}
		}

		/* an example of the patch command: (using /cache for cachedir)
		 * xdelta patch /cache/pacman_3.0.0-1_to_3.0.1-1-i686.delta \
		 *              /cache/pacman-3.0.0-1-i686.pkg.tar.gz       \
		 *              /cache/pacman-3.0.1-1-i686.pkg.tar.gz
		 */

		/* build the patch command */
		snprintf(command, PATH_MAX,
				"xdelta patch"         /* the command */
				" %s/%s"               /* the delta */
				" %s/%s-%s-%s" PKGEXT  /* the 'from' package */
				" %s/%s-%s-%s" PKGEXT, /* the 'to' package */
				cachedir, d->filename,
				cachedir, pkg->name, d->from, pkg->arch,
				cachedir, pkg->name, d->to, pkg->arch);

		_alpm_log(PM_LOG_DEBUG, _("command: %s\n"), command);

		snprintf(pkgfilename, PATH_MAX, "%s-%s-%s" PKGEXT,
				pkg->name, d->to, pkg->arch);

		EVENT(trans, PM_TRANS_EVT_DELTA_PATCH_START, pkgfilename, d->filename);

		if(system(command) == 0) {
			EVENT(trans, PM_TRANS_EVT_DELTA_PATCH_DONE, NULL, NULL);

			/* delete the delta file */
			snprintf(fname, PATH_MAX, "%s/%s", cachedir, d->filename);
			unlink(fname);

			/* Delete the 'from' package but only if it is an intermediate
			 * package. The starting 'from' package should be kept, just
			 * as if deltas were not used. Delete the package file if the
			 * previous iteration of the loop used the same package. */
			if(pkg == lastpkg) {
				snprintf(fname, PATH_MAX, "%s/%s-%s-%s" PKGEXT,
						cachedir, pkg->name, d->from, pkg->arch);
				unlink(fname);
			} else {
				lastpkg = pkg;
			}
		} else {
			EVENT(trans, PM_TRANS_EVT_DELTA_PATCH_FAILED, NULL, NULL);
			lastpkg_failed = 1;
			ret = 1;
		}
	}

	return(ret);
}

/** Compares the md5sum of a file to the expected value.
 *
 * If the md5sum does not match, the user is asked whether the file
 * should be deleted.
 *
 * @param trans the transaction
 * @param filename the filename of the file to test
 * @param md5sum the expected md5sum of the file
 * @param data data to write the error messages to
 *
 * @return 0 if the md5sum matched, 1 otherwise
 */
static int test_md5sum(pmtrans_t *trans, const char *filename,
		const char *md5sum, alpm_list_t **data)
{
	char *filepath;
	char *md5sum2;
	char *errormsg = NULL;
	int ret = 0;

	filepath = _alpm_filecache_find(filename);
	md5sum2 = alpm_get_md5sum(filepath);

	if(md5sum == NULL) {
		if(data) {
			/* TODO wtf is this? malloc'd strings for error messages? */
			if((errormsg = calloc(512, sizeof(char))) == NULL) {
				RET_ERR(PM_ERR_MEMORY, -1);
			}
			snprintf(errormsg, 512, _("can't get md5 checksum for file %s\n"),
					filename);
			*data = alpm_list_add(*data, errormsg);
		}
		ret = 1;
	} else if(md5sum2 == NULL) {
		if(data) {
			if((errormsg = calloc(512, sizeof(char))) == NULL) {
				RET_ERR(PM_ERR_MEMORY, -1);
			}
			snprintf(errormsg, 512, _("can't get md5 checksum for file %s\n"),
					filename);
			*data = alpm_list_add(*data, errormsg);
		}
		ret = 1;
	} else if(strcmp(md5sum, md5sum2) != 0) {
		int doremove = 0;
		QUESTION(trans, PM_TRANS_CONV_CORRUPTED_PKG, (char *)filename,
				NULL, NULL, &doremove);
		if(doremove) {
			unlink(filepath);
		}
		if(data) {
			if((errormsg = calloc(512, sizeof(char))) == NULL) {
				RET_ERR(PM_ERR_MEMORY, -1);
			}
			snprintf(errormsg, 512, _("file %s was corrupted (bad MD5 checksum)\n"),
					filename);
			*data = alpm_list_add(*data, errormsg);
		}
		ret = 1;
	}

	FREE(filepath);
	FREE(md5sum2);

	return(ret);
}

/** Compares the md5sum of a delta to the expected value.
 *
 * @param trans the transaction
 * @param delta the delta to test
 * @param data data to write the error messages to
 *
 * @return 0 if the md5sum matched, 1 otherwise
 */
static int test_delta_md5sum(pmtrans_t *trans, pmdelta_t *delta,
		alpm_list_t **data)
{
	const char *filename;
	const char *md5sum;
	int ret = 0;

	filename = alpm_delta_get_filename(delta);
	md5sum = alpm_delta_get_md5sum(delta);

	ret = test_md5sum(trans, filename, md5sum, data);

	return(ret);
}

/** Compares the md5sum of a package to the expected value.
 *
 * @param trans the transaction
 * @param pkg the package to test
 * @param data data to write the error messages to
 *
 * @return 0 if the md5sum matched, 1 otherwise
 */
static int test_pkg_md5sum(pmtrans_t *trans, pmpkg_t *pkg, alpm_list_t **data)
{
	const char *filename;
	const char *md5sum;
	int ret = 0;

	filename = alpm_pkg_get_filename(pkg);
	md5sum = alpm_pkg_get_md5sum(pkg);

	ret = test_md5sum(trans, filename, md5sum, data);

	return(ret);
}

int _alpm_sync_commit(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t **data)
{
	alpm_list_t *i, *j, *files = NULL;
	alpm_list_t *patches = NULL, *deltas = NULL;
	pmtrans_t *tr = NULL;
	int replaces = 0, retval = 0;
	const char *cachedir = NULL;
	int dltotal = 0;

	ALPM_LOG_FUNC;

	ASSERT(db_local != NULL, RET_ERR(PM_ERR_DB_NULL, -1));
	ASSERT(trans != NULL, RET_ERR(PM_ERR_TRANS_NULL, -1));

	cachedir = _alpm_filecache_setup();
	trans->state = STATE_DOWNLOADING;

	/* Sum up the download sizes. This has to be in its own loop because
	 * the download loop is grouped by db. */
	for(j = trans->packages; j; j = j->next) {
		pmsyncpkg_t *sync = j->data;
		pmpkg_t *spkg = sync->pkg;
		dltotal += alpm_pkg_download_size(spkg, db_local);
	}

	/* group sync records by repository and download */
	for(i = handle->dbs_sync; i; i = i->next) {
		pmdb_t *current = i->data;

		for(j = trans->packages; j; j = j->next) {
			pmsyncpkg_t *sync = j->data;
			pmpkg_t *spkg = sync->pkg;
			pmdb_t *dbs = spkg->origin_data.db;

			if(current == dbs) {
				const char *fname = NULL;

				fname = alpm_pkg_get_filename(spkg);
				if(trans->flags & PM_TRANS_FLAG_PRINTURIS) {
					EVENT(trans, PM_TRANS_EVT_PRINTURI, (char *)alpm_db_get_url(current),
							(char *)fname);
				} else {
					char *fpath = _alpm_filecache_find(fname);
					if(!fpath) {
						if(handle->usedelta) {
							alpm_list_t *delta_path = pkg_upgrade_delta_path(spkg, db_local);

							if(delta_path) {
								alpm_list_t *dlts = NULL;

								for(dlts = delta_path; dlts; dlts = alpm_list_next(dlts)) {
									pmdelta_t *d = (pmdelta_t *)alpm_list_getdata(dlts);
									char *fpath2 = _alpm_filecache_find(d->filename);

									if(!fpath2) {
										/* add the delta filename to the download list if
										 * it's not in the cache*/
										files = alpm_list_add(files, strdup(d->filename));
									}

									/* save the package and delta so that the xdelta patch
									 * command can be run after the downloads finish */
									patches = alpm_list_add(patches, spkg);
									patches = alpm_list_add(patches, d);

									/* keep a list of the delta files for md5sums */
									deltas = alpm_list_add(deltas, d);
								}

								alpm_list_free(delta_path);
								delta_path = NULL;
							} else {
								/* no deltas to download, so add the file to the
								 * download list */
								files = alpm_list_add(files, strdup(fname));
							}
						} else {
							/* not using deltas, so add the file to the download list */
							files = alpm_list_add(files, strdup(fname));
						}
					}
					FREE(fpath);
				}
			}
		}

		if(files) {
			EVENT(trans, PM_TRANS_EVT_RETRIEVE_START, current->treename, NULL);
			if(_alpm_download_files(files, current->servers, cachedir)) {
				_alpm_log(PM_LOG_WARNING, _("failed to retrieve some files from %s\n"),
						current->treename);
				RET_ERR(PM_ERR_RETRIEVE, -1);
			}
			FREELIST(files);
		}
	}
	if(trans->flags & PM_TRANS_FLAG_PRINTURIS) {
		return(0);
	}

	if(handle->usedelta) {
		int ret = 0;

		/* only output if there are deltas to work with */
		if(deltas) {
			/* Check integrity of deltas */
			EVENT(trans, PM_TRANS_EVT_DELTA_INTEGRITY_START, NULL, NULL);

			for(i = deltas; i; i = i->next) {
				pmdelta_t *d = alpm_list_getdata(i);

				ret = test_delta_md5sum(trans, d, data);

				if(ret == 1) {
					retval = 1;
				} else if(ret == -1) { /* -1 is for serious errors */
					RET_ERR(pm_errno, -1);
				}
			}
			if(retval) {
				pm_errno = PM_ERR_DLT_CORRUPTED;
				goto error;
			}
			EVENT(trans, PM_TRANS_EVT_DELTA_INTEGRITY_DONE, NULL, NULL);

			/* Use the deltas to generate the packages */
			EVENT(trans, PM_TRANS_EVT_DELTA_PATCHES_START, NULL, NULL);
			ret = apply_deltas(trans, patches);
			EVENT(trans, PM_TRANS_EVT_DELTA_PATCHES_DONE, NULL, NULL);

			alpm_list_free(patches);
			patches = NULL;
			alpm_list_free(deltas);
			deltas = NULL;
		}
		if(ret) {
			pm_errno = PM_ERR_DLT_PATCHFAILED;
			goto error;
		}
	}

	/* Check integrity of packages */
	EVENT(trans, PM_TRANS_EVT_INTEGRITY_START, NULL, NULL);

	for(i = trans->packages; i; i = i->next) {
		pmsyncpkg_t *sync = i->data;
		pmpkg_t *spkg = sync->pkg;
		int ret = 0;

		ret = test_pkg_md5sum(trans, spkg, data);

		if(ret == 1) {
			retval = 1;
		} else if(ret == -1) { /* -1 is for serious errors */
			RET_ERR(pm_errno, -1);
		}
	}
	if(retval) {
		pm_errno = PM_ERR_PKG_CORRUPTED;
		goto error;
	}
	EVENT(trans, PM_TRANS_EVT_INTEGRITY_DONE, NULL, NULL);
	if(trans->flags & PM_TRANS_FLAG_DOWNLOADONLY) {
		return(0);
	}

	/* remove conflicting and to-be-replaced packages */
	trans->state = STATE_COMMITING;
	tr = _alpm_trans_new();
	if(tr == NULL) {
		_alpm_log(PM_LOG_ERROR, _("could not create removal transaction\n"));
		goto error;
	}

	if(_alpm_trans_init(tr, PM_TRANS_TYPE_REMOVE, PM_TRANS_FLAG_NODEPS, NULL, NULL, NULL) == -1) {
		_alpm_log(PM_LOG_ERROR, _("could not initialize the removal transaction\n"));
		goto error;
	}

	for(i = trans->packages; i; i = i->next) {
		pmsyncpkg_t *sync = i->data;
		alpm_list_t *j;
		for(j = sync->removes; j; j = j->next) {
			pmpkg_t *pkg = j->data;
			if(!_alpm_pkg_find(pkg->name, tr->packages)) {
				if(_alpm_trans_addtarget(tr, pkg->name) == -1) {
					goto error;
				}
				replaces++;
			}
		}
	}
	if(replaces) {
		_alpm_log(PM_LOG_DEBUG, "removing conflicting and to-be-replaced packages\n");
		if(_alpm_trans_prepare(tr, data) == -1) {
			_alpm_log(PM_LOG_ERROR, _("could not prepare removal transaction\n"));
			goto error;
		}
		/* we want the frontend to be aware of commit details */
		tr->cb_event = trans->cb_event;
		if(_alpm_trans_commit(tr, NULL) == -1) {
			_alpm_log(PM_LOG_ERROR, _("could not commit removal transaction\n"));
			goto error;
		}
	}
	_alpm_trans_free(tr);
	tr = NULL;

	/* install targets */
	_alpm_log(PM_LOG_DEBUG, "installing packages\n");
	tr = _alpm_trans_new();
	if(tr == NULL) {
		_alpm_log(PM_LOG_ERROR, _("could not create transaction\n"));
		goto error;
	}
	if(_alpm_trans_init(tr, PM_TRANS_TYPE_UPGRADE, trans->flags | PM_TRANS_FLAG_NODEPS, trans->cb_event, trans->cb_conv, trans->cb_progress) == -1) {
		_alpm_log(PM_LOG_ERROR, _("could not initialize transaction\n"));
		goto error;
	}
	for(i = trans->packages; i; i = i->next) {
		pmsyncpkg_t *sync = i->data;
		pmpkg_t *spkg = sync->pkg;
		const char *fname;
		char *fpath;

		fname = alpm_pkg_get_filename(spkg);
		/* Loop through the cache dirs until we find a matching file */
		fpath = _alpm_filecache_find(fname);

		if(_alpm_trans_addtarget(tr, fpath) == -1) {
			FREE(fpath);
			goto error;
		}
		FREE(fpath);

		/* using alpm_list_last() is ok because addtarget() adds the new target at the
		 * end of the tr->packages list */
		spkg = alpm_list_last(tr->packages)->data;
		spkg->reason = sync->newreason;
	}
	if(_alpm_trans_prepare(tr, data) == -1) {
		_alpm_log(PM_LOG_ERROR, _("could not prepare transaction\n"));
		/* pm_errno is set by trans_prepare */
		goto error;
	}
	if(_alpm_trans_commit(tr, NULL) == -1) {
		_alpm_log(PM_LOG_ERROR, _("could not commit transaction\n"));
		goto error;
	}
	_alpm_trans_free(tr);
	tr = NULL;

	return(0);

error:
	_alpm_trans_free(tr);
	tr = NULL;
	return(-1);
}

pmsyncpkg_t *_alpm_sync_find(alpm_list_t *syncpkgs, const char* pkgname)
{
	alpm_list_t *i;
	for(i = syncpkgs; i; i = i->next) {
		pmsyncpkg_t *syncpkg = i->data;
		if(!syncpkg) {
			continue;
		}

		pmpkg_t *pkg = alpm_sync_get_pkg(syncpkg);
		if(strcmp(alpm_pkg_get_name(pkg), pkgname) == 0) {
			_alpm_log(PM_LOG_DEBUG, "found package '%s-%s' in sync\n",
								alpm_pkg_get_name(pkg), alpm_pkg_get_version(pkg));
			return(syncpkg);
		}
	}

	_alpm_log(PM_LOG_DEBUG, "package '%s' not found in sync\n", pkgname);
	return(NULL); /* not found */
}

pmpkg_t SYMEXPORT *alpm_sync_get_pkg(const pmsyncpkg_t *sync)
{
	/* Sanity checks */
	ASSERT(sync != NULL, return(NULL));

	return sync->pkg;
}

alpm_list_t SYMEXPORT *alpm_sync_get_removes(const pmsyncpkg_t *sync)
{
	/* Sanity checks */
	ASSERT(sync != NULL, return(NULL));

	return sync->removes;
}

/* vim: set ts=2 sw=2 noet: */