/*
 * rc-depend
 * rc service dependency and ordering
 */

/*
 * Copyright (c) 2007-2015 The OpenRC Authors.
 * See the Authors file at the top-level directory of this distribution and
 * https://github.com/OpenRC/openrc/blob/master/AUTHORS
 *
 * This file is part of OpenRC. It is subject to the license terms in
 * the LICENSE file found in the top-level directory of this
 * distribution and at https://github.com/OpenRC/openrc/blob/master/LICENSE
 * This file may not be copied, modified, propagated, or distributed
 *    except according to the terms contained in the LICENSE file.
 */

#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>

#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <utime.h>

#include "builtins.h"
#include "einfo.h"
#include "queue.h"
#include "rc.h"
#include "rc-misc.h"

extern const char *applet;

RC_DEPTREE *
_rc_deptree_load(int force, int *regen) {
	int fd;
	int retval;
	int serrno = errno;
	int merrno;
	time_t t;
	char file[PATH_MAX];
	struct stat st;
	struct utimbuf ut;
	FILE *fp;

	t = 0;
	if (rc_deptree_update_needed(&t, file) || force != 0) {
		/* Test if we have permission to update the deptree */
		fd = open(RC_DEPTREE_CACHE, O_WRONLY);
		merrno = errno;
		errno = serrno;
		if (fd == -1 && merrno == EACCES)
			return rc_deptree_load();
		close(fd);

		if (regen)
			*regen = 1;
		ebegin("Caching service dependencies");
		retval = rc_deptree_update() ? 0 : -1;
		eend (retval, "Failed to update the dependency tree");

		if (retval == 0) {
			stat(RC_DEPTREE_CACHE, &st);
			if (st.st_mtime < t) {
				eerror("Clock skew detected with `%s'", file);
				eerrorn("Adjusting mtime of `" RC_DEPTREE_CACHE
				    "' to %s", ctime(&t));
				fp = fopen(RC_DEPTREE_SKEWED, "w");
				if (fp != NULL) {
					fprintf(fp, "%s\n", file);
					fclose(fp);
				}
				ut.actime = t;
				ut.modtime = t;
				utime(RC_DEPTREE_CACHE, &ut);
			} else {
				if (exists(RC_DEPTREE_SKEWED))
					unlink(RC_DEPTREE_SKEWED);
			}
		}
		if (force == -1 && regen != NULL)
			*regen = retval;
	}
	return rc_deptree_load();
}

#include "_usage.h"
#define getoptstring "aot:suTF:" getoptstring_COMMON
static const struct option longopts[] = {
	{ "starting", 0, NULL, 'a'},
	{ "stopping", 0, NULL, 'o'},
	{ "type",     1, NULL, 't'},
	{ "notrace",  0, NULL, 'T'},
	{ "strict",   0, NULL, 's'},
	{ "update",   0, NULL, 'u'},
	{ "deptree-file", 1, NULL, 'F'},
	longopts_COMMON
};
static const char * const longopts_help[] = {
	"Order services as if runlevel is starting",
	"Order services as if runlevel is stopping",
	"Type(s) of dependency to list",
	"Don't trace service dependencies",
	"Only use what is in the runlevels",
	"Force an update of the dependency tree",
	"File to load cached deptree from",
	longopts_help_COMMON
};
#include "_usage.c"

int
rc_depend(int argc, char **argv)
{
	RC_STRINGLIST *list;
	RC_STRINGLIST *types;
	RC_STRINGLIST *services;
	RC_STRINGLIST *depends;
	RC_STRING *s;
	RC_DEPTREE *deptree = NULL;
	int options = RC_DEP_TRACE, update = 0;
	bool first = true;
	char *runlevel = xstrdup(getenv("RC_RUNLEVEL"));
	int opt;
	char *token;
	char *deptree_file = NULL;

	types = rc_stringlist_new();
	while ((opt = getopt_long(argc, argv, getoptstring,
		    longopts, (int *) 0)) != -1)
	{
		switch (opt) {
		case 'a':
			options |= RC_DEP_START;
			break;
		case 'o':
			options |= RC_DEP_STOP;
			break;
		case 's':
			options |= RC_DEP_STRICT;
			break;
		case 't':
			while ((token = strsep(&optarg, ",")))
				rc_stringlist_add(types, token);
			break;
		case 'u':
			update = 1;
			break;
		case 'T':
			options &= RC_DEP_TRACE;
			break;
		case 'F':
			deptree_file = xstrdup(optarg);
			break;

		case_RC_COMMON_GETOPT
		}
	}

	if (deptree_file) {
		if (!(deptree = rc_deptree_load_file(deptree_file)))
			eerrorx("failed to load deptree");
	} else {
		if (!(deptree = _rc_deptree_load(update, NULL)))
			eerrorx("failed to load deptree");
	}

	if (!runlevel)
		runlevel = rc_runlevel_get();

	services = rc_stringlist_new();
	while (optind < argc) {
		list = rc_stringlist_new();
		rc_stringlist_add(list, argv[optind]);
		errno = 0;
		depends = rc_deptree_depends(deptree, NULL, list, runlevel, 0);
		if (!depends && errno == ENOENT)
			eerror("no dependency info for service `%s'",
			    argv[optind]);
		else
			rc_stringlist_add(services, argv[optind]);

		rc_stringlist_free(depends);
		rc_stringlist_free(list);
		optind++;
	}
	if (!TAILQ_FIRST(services)) {
		rc_stringlist_free(services);
		rc_stringlist_free(types);
		rc_deptree_free(deptree);
		free(runlevel);
		if (update)
			return EXIT_SUCCESS;
		eerrorx("no services specified");
	}

	/* If we don't have any types, then supply some defaults */
	if (!TAILQ_FIRST(types)) {
		rc_stringlist_add(types, "ineed");
		rc_stringlist_add(types, "iuse");
	}

	depends = rc_deptree_depends(deptree, types, services,
	    runlevel, options);

	if (TAILQ_FIRST(depends)) {
		TAILQ_FOREACH(s, depends, entries) {
			if (first)
				first = false;
			else
				printf (" ");
			printf ("%s", s->value);

		}
		printf ("\n");
	}

	rc_stringlist_free(types);
	rc_stringlist_free(services);
	rc_stringlist_free(depends);
	rc_deptree_free(deptree);
	free(runlevel);
	return EXIT_SUCCESS;
}