/* copyright 2000, 2001 Sun Microsystems, Inc.
 * Copyright 2001, Red Hat, Inc., Ximian, Inc.
 * Copyright 2003, Malcolm Tredinnick.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 * Some of this code (the temporary directory stuff) was originally copied from
 * ORBit2/linc2/src/linc-protocols.c and modified to fit into scrollkeeper. The
 * copyright attributions from that file have been added to this file.
 */

#include <config.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <libintl.h>
#include <libxml/tree.h>
#include <scrollkeeper.h>
#include <errno.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/stat.h>
#include <locale.h>
#include <fcntl.h>
#include <utime.h>
#include <pwd.h>

/*
 * make_local_tmpdir:
 * @dirname: directory name.
 *
 * Create a directory with the name in @dirname. Also, clear the access and
 * modification times of @dirname.
 *
 * If the directory already exists and is not owned by the current user, or is
 * not solely readable by the current user, then linc will error out.
 *
 */
static void
make_local_tmpdir (const char *dirname, char outputprefs)
{
	struct stat statbuf;
		
	if (mkdir (dirname, 0700) != 0) {
		int e = errno;
			
		switch (e) {
		case 0:
		case EEXIST:
			if (stat (dirname, &statbuf) != 0) {
				sk_message (outputprefs, SKOUT_DEFAULT, SKOUT_QUIET, "scrollkeeper-get-cl", _("Cannot stat %s\n"), dirname);
				exit (EXIT_FAILURE);
			}

#ifndef __CYGWIN__
			if (statbuf.st_uid != getuid ()) {
				sk_message (outputprefs, SKOUT_DEFAULT, SKOUT_QUIET, "scrollkeeper-get-cl", _("Owner of %s is not the current user\n"), dirname);
				exit (EXIT_FAILURE);
			}

			if ((statbuf.st_mode & (S_IRWXG|S_IRWXO)) ||
			    !S_ISDIR (statbuf.st_mode)) {
				sk_message (outputprefs, SKOUT_DEFAULT, SKOUT_QUIET, "scrollkeeper-get-cl", _("Wrong permissions for %s\n"), dirname);
				exit (EXIT_FAILURE);
			}
#endif

			break;
				
		default:
			sk_message (outputprefs, SKOUT_DEFAULT, SKOUT_QUIET, "scrollkeeper-get-cl", _("Unknown error on directory creation of %s (%s)\n"),
				dirname, strerror (e));
			exit (EXIT_FAILURE);
		}
	}

	{
		/* Hide some information (useful on systems with weak random
		 * number generators). */
		struct utimbuf utb;
		memset (&utb, 0, sizeof (utb));
		utime (dirname, &utb);
	}
}

/* Cycles through five temporary filenames of the form *
 * /tmp/.../scrollkeeper-tempfile.x, where x is number from 0 to 4 and returns
 * the first one that does not exist or the oldest one.
 */
static char *get_next_free_temp_file_path(char outputprefs)
{
	char path[PATHLEN], *filename, *user_name, user_dir[PATHLEN];
	int i, num, fd;
	struct stat buf;
	time_t prev;
	struct passwd *pw;
	
	prev = 0;
	num = 0;

	/* FIXME: Not threadsafe. Should ultimately be replaced with glib
	 * functionality. */
	setpwent ();
	pw = getpwuid (getuid ());
	endpwent ();
	if (pw) {
		user_name = strdup (pw->pw_name);
	}
	else {
		sk_message (outputprefs, SKOUT_DEFAULT, SKOUT_QUIET, "scrollkeeper-get-cl", _("Unable to determine username."));
		exit (EXIT_FAILURE);
	}
	snprintf (user_dir, PATHLEN, "/tmp/scrollkeeper-%s", user_name);
	free (user_name);
	make_local_tmpdir (user_dir, outputprefs);
	
	for(i = 0; i < 5; i++) {
		snprintf(path, PATHLEN, "%s/contents.%d", user_dir, i);
		if (stat(path, &buf) == -1) {
			if (errno == ENOENT) {
				/* this is an empty slot so use it */
				
				num = i;
				break;
			}
			else {
                                sk_message(outputprefs, SKOUT_DEFAULT, SKOUT_QUIET, "scrollkeeper-get-cl", _("Cannot open temporary file.\n"));
				exit(EXIT_FAILURE);
			}
		} else {
			if (i == 0) {
				prev = buf.st_ctime;
			} else {
				if (prev > buf.st_ctime) {
					/* this is the oldest so use it */
				
					num = i;
					break;
				}
			}
		}
		
	}
	
	if (i == 5) {
		/* if we got here it means that all slots are taken
		   and the first is the oldest
		*/
		
		num = 0;
	}

	filename = malloc(sizeof(char)*PATHLEN);
	check_ptr(filename, "scrollkeeper-get-cl");
	snprintf(filename, PATHLEN, "%s/contents.%d", user_dir, num);

	unlink(filename);
	
	fd = open(filename, O_RDWR | O_CREAT | O_EXCL | O_TRUNC | O_NONBLOCK,
		  S_IRWXU | S_IRGRP | S_IROTH);

	if (fd < 0) {
	        fprintf (stderr, _("%s: Cannot open temp file: %s\n"), "scrolkeeper-get-cl",  filename);
		exit (EXIT_FAILURE);
	}
	close(fd);
	
	return filename;
}

static void
usage (int argc, char **argv) {
    
    	if (argc != 3 && argc != 4) {
    		printf(
	    	_("Usage: %s [-v] <LOCALE> <CATEGORY TREE FILE NAME>\n"), *argv);
		exit(EXIT_SUCCESS);
    	}
}

int main(int argc, char **argv)
{
    	FILE *config_fid;
    	char scrollkeeper_dir[PATHLEN], *locale;
    	char *base_name, *path;
	xmlDocPtr merged_tree;
        char outputprefs=0;

    	setlocale (LC_ALL, "");
    	bindtextdomain (PACKAGE, SCROLLKEEPERLOCALEDIR);
    	textdomain (PACKAGE);

    	usage(argc, argv);

    	if (argc == 3)
    	{
    		locale = argv[1];
    		base_name = argv[2];
    	}
    	else /* argc == 4 */
    	{
		outputprefs = outputprefs | SKOUT_STD_VERBOSE | SKOUT_LOG_VERBOSE;
		locale = argv[2];
		base_name = argv[3];
    	}
	
	umask(0022);

    	config_fid = popen("scrollkeeper-config --pkglocalstatedir", "r");
    	fscanf(config_fid, "%s", scrollkeeper_dir);  /* XXX buffer overflow */
    	pclose(config_fid);

    	merged_tree = merge_locale_trees(scrollkeeper_dir, locale, base_name);
	
	if (merged_tree == NULL) {
		sk_message(outputprefs, SKOUT_DEFAULT, SKOUT_QUIET, "get_next_free_temp_file_path", _("No Content List for this locale.\n"));
		return 1;
	}
	
	path = get_next_free_temp_file_path(outputprefs);
	check_ptr(path, "scrollkeeper-get-cl");
	
	xmlSaveFile(path, merged_tree);
	printf("%s\n", path);
	free(path);
	
	return 0;
}