/* Copyright (C) 2009 Luke Shumaker
   
   This file is part of rvs.
   
   rvs 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, or (at your
   option) any later version.
   
   rvs is distributed in the hope    1. A user enters a username and passwthat 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 rvs; see the file COPYING.
   If not, write to the Free Software Foundation,
   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/

#include <stdio.h>
#include <stdlib.h> /* EXIT_FAILURE */
#include <unistd.h> /* file acces */
#include <string.h>

#include <errno.h>
#include <error.h>

#include <dirent.h>
#include <sys/stat.h>

#include "rvs.h"
#include "plugin.h"

void _parse_comment (FILE *file)
{
	char c;
	while ( (c=getc(file)) != EOF ) {
		if ( c == '\n' ) {
			ungetc (c, file);
			break;
		}
	}
}

char _parse_escape(FILE *file)
{
	char c=getc(file);
	switch (c) {
		case 'n':
			c = '\n';
		case '\\':
		case '#':
		case ':':
			break;
		default:
			error(EXIT_FAILURE,0,"syntax error");
			break;
	}
	return c;
}

char *_parse_depend (FILE *file)
{
	size_t nbytes = 10;
	char *string = (char *)xmalloc(nbytes);
	
	char c[2] = " \0";
	char *cs = (char *)&c;
	while ( (c[0]=getc(file)) != EOF ) {
		if (c[0] == '\n') {
			ungetc (c[0], file);
			break;
		} else {
			switch (c[0]) {
				case '\\':
					c[0]=_parse_escape(file);
					stradds(&nbytes,&string,cs);
					break;
				case '#':
					_parse_comment(file);
					break;
				default:
					stradds(&nbytes,&string,cs);
					break;
			}
		}
	}
	return string;
}

struct plugin_command *_parse_plugin (struct plugin *plugin, FILE *file)
{
	struct plugin_command *command;
	command=(struct plugin_command *)xmalloc(sizeof(*command));
	command->p_next=NULL;
	command->depends=NULL;
	
	size_t nbytes = 10;
	char *string = (char *)xmalloc(nbytes);
	strcpy(string,"");

	char c[2] = " \0";
	char *cs = (char *)&c;
	if ( (c[0]=getc(file)) == EOF ) {
		return NULL;
	} else {
		ungetc (c[0], file);
	}
	while ( (c[0]=getc(file)) != EOF ) {
		if (c[0] == '\n') {
			if (strcmp(string,"")==0) {
				free(command);
				free(string);
				return _parse_plugin(plugin, file);
			} else {
				command->name=string;
				command->p_next=_parse_plugin(plugin, file);
				break;
			}
		} else {
			switch (c[0]) {
				case '\\':
					c[0]=_parse_escape(file);
					stradds(&nbytes,&string,cs);
					break;
				case '#':
					_parse_comment(file);
					break;
				case ':':
					command->depends=_parse_depend(file);
					break;
				default:
					stradds(&nbytes,&string,cs);
					break;
			}
		}
	}
	return command;
}

struct plugin *load_plugin (char *plug_name, char *plugin_conf)
{
	printf("loading plugin `%s'\n",plug_name);
	struct plugin *plugin=(struct plugin *)xmalloc(sizeof(*plugin));
	plugin->name=plug_name;
	plugin->next=NULL;
	
	chdir(plug_name);
	FILE *file = xfopen(plugin_conf,"r");
	
	plugin->child=_parse_plugin(plugin, file);
	
	fclose( file );
	chdir("..");
	return plugin;
}

struct plugin_tree *load_plugins (char *libexecdir, char *plugin_conf)
{
	struct plugin_tree *tree=(struct plugin_tree *)xmalloc(sizeof(*tree));
	struct plugin **last=&tree->plugins;
	struct plugin *plugin;
	
	chdir(libexecdir);
	DIR *cwd;
	struct dirent *dirent;
	int serr;
	struct stat sbuf;
	cwd = xopendir ("./");
	while ( (dirent = readdir (cwd)) != NULL ) {
		if ((strcmp(dirent->d_name,"." )!=0)&&
		    (strcmp(dirent->d_name,"..")!=0)) {
			serr = stat(dirent->d_name, &sbuf);
			if (!serr && S_ISDIR(sbuf.st_mode)) {
				plugin=load_plugin(dirent->d_name,plugin_conf);
				*last=plugin;
				last=&plugin->next;
			}
		}
	}
	closedir (cwd);
	return tree;
}