/*
 * (POP3Lite) Alias - 3lite POP3 Daemon (user alias support)
 * Copyright (C) 2000, 2001 Gergely Nagy <8@free.bsd.hu>
 *
 * This file is part of POP3Lite.
 *
 * POP3Lite 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.
 *
 * POP3Lite 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#ifdef HAVE_CONFIG_H
#	include <config.h>
#endif

#include <pop3lite.h>
#include <glib.h>

#include <string.h>

#ifdef DEBUG
#	include <syslog.h>
#endif

#include "alias.h"

static const char rcsid[]="$Id: alias.c,v 1.6 2001/01/12 15:58:59 algernon Exp $";

int alias_LTX_module_done ( P3LControl *control );
int alias_LTX_module_init ( P3LControl *control );

static char* alias_default_get_alias ( P3LControl *control, const char *user );
static CommandResponse *alias_cmd_auth_user ( P3LControl *control, const char *user );

static P3LHook_alias_get_alias B_alias_get_alias;
static p3l_pop3_command B_alias_auth_user;

/**
 * alias_default_get_alias: default ALIAS-GET-ALIAS hook
 * @control: the usual control struct
 * @user: the user whose alias we want
 *
 * Retrieves the alias to a given username, from a file.
 * Multiple-level aliases (eg: www-data->root->user)
 * are NOT supported. (But a module calling this function
 * in a loop can easily implement that behaviour too.)
 *
 * Returns: the alias or the original filename
 **/

static char *
alias_default_get_alias ( P3LControl *control, const char *user )
{
	gpointer buffer;
	char *filename, **line_s, *line, *alias;
	P3LString **lines;
	size_t linecnt, bsize, i=0;

#ifdef DEBUG
	control->system->log ( control, LOG_DEBUG, "%s:%d: handling ALIAS-GET-ALIAS",
			       __FILE__, __LINE__ );
#endif

	alias = g_strdup ( user );

	/*
	 * Get the filename...
	 */

	filename = P3L_GET_FIRST_OPTION ( "ALIAS.ALIAS_MAP" );

	if ( filename == NULL )
		filename = SYSCONFDIR "/pop3lite.usermap";

	/*
	 * Read the file
	 */

	if ( ( buffer = p3l_read_file ( filename, &bsize ) ) == NULL )
		return alias;

	/*
	 * Get the alias
	 */

	lines = p3l_split_lines ( buffer, bsize, &linecnt );
	while ( lines[i] != NULL && i < linecnt )
	{
		line = (char *) g_malloc ( lines[i]->length + 1 );
		memcpy ( line, lines[i]->str, lines[i]->length );
		line[lines[i]->length-1]=0;
		/*
		 * Split into at most three parts. We only use
		 * the first two, but other modules may use the
		 * rest (eg the virtual-host module), so we allow
		 * other info to be on the line
		 */
		line_s = g_strsplit ( line, ":", 2 );
		g_free ( line );
		if ( ! strcmp ( line_s[0], user ) )
		{
			alias = g_strdup ( line_s[1] );
			g_strfreev ( line_s );
			break;
		}
		i++;
		g_strfreev ( line_s );
	}

	g_free ( buffer );

	return alias;
}

/**
 * alias_cmd_auth_user: USER hook
 * @control: the usual control struct
 * @user: the username given by the client
 *
 * Adds a hook on top of the original USER handler.
 * Note: ON TOP! This is not a replacement!
 *
 * Returns: the same as the underlying handler would,
 * after the alias resolving, with the given username.
 **/

static CommandResponse *
alias_cmd_auth_user ( P3LControl *control, const char *user )
{
	char *alias;
	CommandResponse *resp;

#ifdef DEBUG
	control->system->log ( control, LOG_DEBUG, "%s:%d: handling USER (%s)",
			       __FILE__, __LINE__, user );
#endif

	if ( user == NULL )
		return p3l_respond ( POP3_ERR, "Invalid username" );

	if ( P3L_HOOK_EXISTS ( "ALIAS-GET-ALIAS" ) )
		alias = P3L_CALL_HOOK ( P3LHook_alias_get_alias, 
					"ALIAS-GET-ALIAS" ) ( control, user );
	else
		alias = g_strdup ( user );

	resp = (*B_alias_auth_user) ( control, alias );

	if ( resp->code == POP3_OK )
		resp->message = g_strdup_printf ("%s selected", user );

	g_hash_table_insert ( control->data, "CLIENT_USER", g_strdup ( user ) );

	return resp;
}

int
alias_LTX_module_init ( P3LControl *control )
{
#ifdef DEBUG
	control->system->log ( control, LOG_DEBUG, "%s:%d: init mod-Alias",
			       __FILE__, __LINE__ );
#endif

	/*
	 * If we have an existing USER handler, everything is fine, if not,
	 * we do not install ourselves, because we depend on the underlying
	 * handler.
	 */

	if ( g_hash_table_lookup ( control->auth_commands, "USER" ) != NULL )
	{
		B_alias_get_alias = (P3LHook_alias_get_alias)
			p3l_command_replace ( control->hooks, "ALIAS-GET-ALIAS",
					      (gpointer) alias_default_get_alias );
		B_alias_auth_user = (p3l_pop3_command)
			p3l_command_replace ( control->auth_commands, "USER",
					      (gpointer) alias_cmd_auth_user );
		return 0;
	}

	return -1;
}

int
alias_LTX_module_done ( P3LControl *control )
{
#ifdef DEBUG
	control->system->log ( control, LOG_DEBUG, "%s:%d: done mod-Alias",
			       __FILE__, __LINE__ );
#endif

	g_hash_table_insert ( control->hooks, "ALIAS-GET-ALIAS",
			      (gpointer) B_alias_get_alias );
	g_hash_table_insert ( control->auth_commands, "USER",
			      (gpointer) B_alias_auth_user );

	return 0;
}