/*
 *  trans.c
 *
 *  Copyright (c) 2006-2018 Pacman Development Team <pacman-dev@archlinux.org>
 *  Copyright (c) 2002-2006 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 <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <errno.h>
#include <limits.h>

/* libalpm */
#include "trans.h"
#include "alpm_list.h"
#include "package.h"
#include "util.h"
#include "log.h"
#include "handle.h"
#include "remove.h"
#include "sync.h"
#include "alpm.h"
#include "deps.h"
#include "hook.h"

/** \addtogroup alpm_trans Transaction Functions
 * @brief Functions to manipulate libalpm transactions
 * @{
 */

/** Initialize the transaction. */
int SYMEXPORT alpm_trans_init(alpm_handle_t *handle, int flags)
{
	alpm_trans_t *trans;

	/* Sanity checks */
	CHECK_HANDLE(handle, return -1);
	ASSERT(handle->trans == NULL, RET_ERR(handle, ALPM_ERR_TRANS_NOT_NULL, -1));

	/* lock db */
	if(!(flags & ALPM_TRANS_FLAG_NOLOCK)) {
		if(_alpm_handle_lock(handle)) {
			RET_ERR(handle, ALPM_ERR_HANDLE_LOCK, -1);
		}
	}

	CALLOC(trans, 1, sizeof(alpm_trans_t), RET_ERR(handle, ALPM_ERR_MEMORY, -1));
	trans->flags = flags;
	trans->state = STATE_INITIALIZED;

	handle->trans = trans;

	return 0;
}

static alpm_list_t *check_arch(alpm_handle_t *handle, alpm_list_t *pkgs)
{
	alpm_list_t *i;
	alpm_list_t *invalid = NULL;

	const char *arch = handle->arch;
	if(!arch) {
		return NULL;
	}
	for(i = pkgs; i; i = i->next) {
		alpm_pkg_t *pkg = i->data;
		const char *pkgarch = alpm_pkg_get_arch(pkg);
		if(pkgarch && strcmp(pkgarch, arch) && strcmp(pkgarch, "any")) {
			char *string;
			const char *pkgname = pkg->name;
			const char *pkgver = pkg->version;
			size_t len = strlen(pkgname) + strlen(pkgver) + strlen(pkgarch) + 3;
			MALLOC(string, len, RET_ERR(handle, ALPM_ERR_MEMORY, invalid));
			sprintf(string, "%s-%s-%s", pkgname, pkgver, pkgarch);
			invalid = alpm_list_add(invalid, string);
		}
	}
	return invalid;
}

/** Prepare a transaction. */
int SYMEXPORT alpm_trans_prepare(alpm_handle_t *handle, alpm_list_t **data)
{
	alpm_trans_t *trans;

	/* Sanity checks */
	CHECK_HANDLE(handle, return -1);
	ASSERT(data != NULL, RET_ERR(handle, ALPM_ERR_WRONG_ARGS, -1));

	trans = handle->trans;

	ASSERT(trans != NULL, RET_ERR(handle, ALPM_ERR_TRANS_NULL, -1));
	ASSERT(trans->state == STATE_INITIALIZED, RET_ERR(handle, ALPM_ERR_TRANS_NOT_INITIALIZED, -1));

	/* If there's nothing to do, return without complaining */
	if(trans->add == NULL && trans->remove == NULL) {
		return 0;
	}

	alpm_list_t *invalid = check_arch(handle, trans->add);
	if(invalid) {
		if(data) {
			*data = invalid;
		}
		RET_ERR(handle, ALPM_ERR_PKG_INVALID_ARCH, -1);
	}

	if(trans->add == NULL) {
		if(_alpm_remove_prepare(handle, data) == -1) {
			/* pm_errno is set by _alpm_remove_prepare() */
			return -1;
		}
	}	else {
		if(_alpm_sync_prepare(handle, data) == -1) {
			/* pm_errno is set by _alpm_sync_prepare() */
			return -1;
		}
	}


	if(!(trans->flags & ALPM_TRANS_FLAG_NODEPS)) {
		_alpm_log(handle, ALPM_LOG_DEBUG, "sorting by dependencies\n");
		if(trans->add) {
			alpm_list_t *add_orig = trans->add;
			trans->add = _alpm_sortbydeps(handle, add_orig, trans->remove, 0);
			alpm_list_free(add_orig);
		}
		if(trans->remove) {
			alpm_list_t *rem_orig = trans->remove;
			trans->remove = _alpm_sortbydeps(handle, rem_orig, NULL, 1);
			alpm_list_free(rem_orig);
		}
	}

	trans->state = STATE_PREPARED;

	return 0;
}

/** Commit a transaction. */
int SYMEXPORT alpm_trans_commit(alpm_handle_t *handle, alpm_list_t **data)
{
	alpm_trans_t *trans;
	alpm_event_any_t event;

	/* Sanity checks */
	CHECK_HANDLE(handle, return -1);

	trans = handle->trans;

	ASSERT(trans != NULL, RET_ERR(handle, ALPM_ERR_TRANS_NULL, -1));
	ASSERT(trans->state == STATE_PREPARED, RET_ERR(handle, ALPM_ERR_TRANS_NOT_PREPARED, -1));

	ASSERT(!(trans->flags & ALPM_TRANS_FLAG_NOLOCK), RET_ERR(handle, ALPM_ERR_TRANS_NOT_LOCKED, -1));

	/* If there's nothing to do, return without complaining */
	if(trans->add == NULL && trans->remove == NULL) {
		return 0;
	}

	if(trans->add) {
		if(_alpm_sync_load(handle, data) != 0) {
			/* pm_errno is set by _alpm_sync_load() */
			return -1;
		}
		if(trans->flags & ALPM_TRANS_FLAG_DOWNLOADONLY) {
			return 0;
		}
		if(_alpm_sync_check(handle, data) != 0) {
			/* pm_errno is set by _alpm_sync_check() */
			return -1;
		}
	}

	if(_alpm_hook_run(handle, ALPM_HOOK_PRE_TRANSACTION) != 0) {
		RET_ERR(handle, ALPM_ERR_TRANS_HOOK_FAILED, -1);
	}

	trans->state = STATE_COMMITING;

	alpm_logaction(handle, ALPM_CALLER_PREFIX, "transaction started\n");
	event.type = ALPM_EVENT_TRANSACTION_START;
	EVENT(handle, (void *)&event);

	if(trans->add == NULL) {
		if(_alpm_remove_packages(handle, 1) == -1) {
			/* pm_errno is set by _alpm_remove_packages() */
			alpm_errno_t save = handle->pm_errno;
			alpm_logaction(handle, ALPM_CALLER_PREFIX, "transaction failed\n");
			handle->pm_errno = save;
			return -1;
		}
	} else {
		if(_alpm_sync_commit(handle) == -1) {
			/* pm_errno is set by _alpm_sync_commit() */
			alpm_errno_t save = handle->pm_errno;
			alpm_logaction(handle, ALPM_CALLER_PREFIX, "transaction failed\n");
			handle->pm_errno = save;
			return -1;
		}
	}

	if(trans->state == STATE_INTERRUPTED) {
		alpm_logaction(handle, ALPM_CALLER_PREFIX, "transaction interrupted\n");
	} else {
		event.type = ALPM_EVENT_TRANSACTION_DONE;
		EVENT(handle, (void *)&event);
		alpm_logaction(handle, ALPM_CALLER_PREFIX, "transaction completed\n");
		_alpm_hook_run(handle, ALPM_HOOK_POST_TRANSACTION);
	}

	trans->state = STATE_COMMITED;

	_alpm_log(handle, ALPM_LOG_DEBUG, "synchronizing filesystem\n");
	sync();

	return 0;
}

/** Interrupt a transaction.
 * @note Safe to call from inside signal handlers.
 */
int SYMEXPORT alpm_trans_interrupt(alpm_handle_t *handle)
{
	alpm_trans_t *trans;

	/* Sanity checks */
	CHECK_HANDLE(handle, return -1);

	trans = handle->trans;
	ASSERT(trans != NULL, RET_ERR_ASYNC_SAFE(handle, ALPM_ERR_TRANS_NULL, -1));
	ASSERT(trans->state == STATE_COMMITING || trans->state == STATE_INTERRUPTED,
			RET_ERR_ASYNC_SAFE(handle, ALPM_ERR_TRANS_TYPE, -1));

	trans->state = STATE_INTERRUPTED;

	return 0;
}

/** Release a transaction. */
int SYMEXPORT alpm_trans_release(alpm_handle_t *handle)
{
	alpm_trans_t *trans;

	/* Sanity checks */
	CHECK_HANDLE(handle, return -1);

	trans = handle->trans;
	ASSERT(trans != NULL, RET_ERR(handle, ALPM_ERR_TRANS_NULL, -1));
	ASSERT(trans->state != STATE_IDLE, RET_ERR(handle, ALPM_ERR_TRANS_NULL, -1));

	int nolock_flag = trans->flags & ALPM_TRANS_FLAG_NOLOCK;

	_alpm_trans_free(trans);
	handle->trans = NULL;

	/* unlock db */
	if(!nolock_flag) {
		_alpm_handle_unlock(handle);
	}

	return 0;
}

/** @} */

void _alpm_trans_free(alpm_trans_t *trans)
{
	if(trans == NULL) {
		return;
	}

	alpm_list_free_inner(trans->unresolvable,
			(alpm_list_fn_free)_alpm_pkg_free_trans);
	alpm_list_free(trans->unresolvable);
	alpm_list_free_inner(trans->add, (alpm_list_fn_free)_alpm_pkg_free_trans);
	alpm_list_free(trans->add);
	alpm_list_free_inner(trans->remove, (alpm_list_fn_free)_alpm_pkg_free);
	alpm_list_free(trans->remove);

	FREELIST(trans->skip_remove);

	FREE(trans);
}

/* A cheap grep for text files, returns 1 if a substring
 * was found in the text file fn, 0 if it wasn't
 */
static int grep(const char *fn, const char *needle)
{
	FILE *fp;
	char *ptr;

	if((fp = fopen(fn, "r")) == NULL) {
		return 0;
	}
	while(!feof(fp)) {
		char line[1024];
		if(safe_fgets(line, sizeof(line), fp) == NULL) {
			continue;
		}
		if((ptr = strchr(line, '#')) != NULL) {
			*ptr = '\0';
		}
		/* TODO: this will not work if the search string
		 * ends up being split across line reads */
		if(strstr(line, needle)) {
			fclose(fp);
			return 1;
		}
	}
	fclose(fp);
	return 0;
}

int _alpm_runscriptlet(alpm_handle_t *handle, const char *filepath,
		const char *script, const char *ver, const char *oldver, int is_archive)
{
	char arg0[64], arg1[3], cmdline[PATH_MAX];
	char *argv[] = { arg0, arg1, cmdline, NULL };
	char *tmpdir, *scriptfn = NULL, *scriptpath;
	int retval = 0;
	size_t len;

	if(_alpm_access(handle, NULL, filepath, R_OK) != 0) {
		_alpm_log(handle, ALPM_LOG_DEBUG, "scriptlet '%s' not found\n", filepath);
		return 0;
	}

	if(!is_archive && !grep(filepath, script)) {
		/* script not found in scriptlet file; we can only short-circuit this early
		 * if it is an actual scriptlet file and not an archive. */
		return 0;
	}

	strcpy(arg0, SCRIPTLET_SHELL);
	strcpy(arg1, "-c");

	/* create a directory in $root/tmp/ for copying/extracting the scriptlet */
	len = strlen(handle->root) + strlen("tmp/alpm_XXXXXX") + 1;
	MALLOC(tmpdir, len, RET_ERR(handle, ALPM_ERR_MEMORY, -1));
	snprintf(tmpdir, len, "%stmp/", handle->root);
	if(access(tmpdir, F_OK) != 0) {
		_alpm_makepath_mode(tmpdir, 01777);
	}
	snprintf(tmpdir, len, "%stmp/alpm_XXXXXX", handle->root);
	if(mkdtemp(tmpdir) == NULL) {
		_alpm_log(handle, ALPM_LOG_ERROR, _("could not create temp directory\n"));
		free(tmpdir);
		return 1;
	}

	/* either extract or copy the scriptlet */
	len += strlen("/.INSTALL");
	MALLOC(scriptfn, len, free(tmpdir); RET_ERR(handle, ALPM_ERR_MEMORY, -1));
	snprintf(scriptfn, len, "%s/.INSTALL", tmpdir);
	if(is_archive) {
		if(_alpm_unpack_single(handle, filepath, tmpdir, ".INSTALL")) {
			retval = 1;
		}
	} else {
		if(_alpm_copyfile(filepath, scriptfn)) {
			_alpm_log(handle, ALPM_LOG_ERROR, _("could not copy tempfile to %s (%s)\n"), scriptfn, strerror(errno));
			retval = 1;
		}
	}
	if(retval == 1) {
		goto cleanup;
	}

	if(is_archive && !grep(scriptfn, script)) {
		/* script not found in extracted scriptlet file */
		goto cleanup;
	}

	/* chop off the root so we can find the tmpdir in the chroot */
	scriptpath = scriptfn + strlen(handle->root) - 1;

	if(oldver) {
		snprintf(cmdline, PATH_MAX, ". %s; %s %s %s",
				scriptpath, script, ver, oldver);
	} else {
		snprintf(cmdline, PATH_MAX, ". %s; %s %s",
				scriptpath, script, ver);
	}

	_alpm_log(handle, ALPM_LOG_DEBUG, "executing \"%s\"\n", cmdline);

	retval = _alpm_run_chroot(handle, SCRIPTLET_SHELL, argv, NULL, NULL);

cleanup:
	if(scriptfn && unlink(scriptfn)) {
		_alpm_log(handle, ALPM_LOG_WARNING,
				_("could not remove %s\n"), scriptfn);
	}
	if(rmdir(tmpdir)) {
		_alpm_log(handle, ALPM_LOG_WARNING,
				_("could not remove tmpdir %s\n"), tmpdir);
	}

	free(scriptfn);
	free(tmpdir);
	return retval;
}

int SYMEXPORT alpm_trans_get_flags(alpm_handle_t *handle)
{
	/* Sanity checks */
	CHECK_HANDLE(handle, return -1);
	ASSERT(handle->trans != NULL, RET_ERR(handle, ALPM_ERR_TRANS_NULL, -1));

	return handle->trans->flags;
}

alpm_list_t SYMEXPORT *alpm_trans_get_add(alpm_handle_t *handle)
{
	/* Sanity checks */
	CHECK_HANDLE(handle, return NULL);
	ASSERT(handle->trans != NULL, RET_ERR(handle, ALPM_ERR_TRANS_NULL, NULL));

	return handle->trans->add;
}

alpm_list_t SYMEXPORT *alpm_trans_get_remove(alpm_handle_t *handle)
{
	/* Sanity checks */
	CHECK_HANDLE(handle, return NULL);
	ASSERT(handle->trans != NULL, RET_ERR(handle, ALPM_ERR_TRANS_NULL, NULL));

	return handle->trans->remove;
}
