/*  MasqMail
    Copyright (C) 2000-2001 Oliver Kurth

    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, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/

#include "masqmail.h"
#include <fnmatch.h>

gboolean addr_is_local(address *addr)
{
  GList *dom_node;
  GList *addr_node;
  address *a;

  foreach(conf.local_hosts, dom_node){
    if(addr->domain == NULL)
      return TRUE;
    if(fnmatch(dom_node->data, addr->domain, FNM_CASEFOLD) == 0){
      foreach(conf.not_local_addresses,addr_node){
	a = create_address_qualified(addr_node->data, TRUE, conf.host_name);
	if(addr_isequal(a,addr)){
	  destroy_address(a);
	  return FALSE;
	}
	destroy_address(a);
      }
      return TRUE;
    }
  }
  foreach(conf.local_addresses,addr_node){
    a = create_address_qualified(addr_node->data, TRUE, conf.host_name);
    if(addr_isequal(a,addr)){
      destroy_address(a);
      return TRUE;
    }
    destroy_address(a);
  }
  return FALSE;
}

static
gboolean addr_isequal_alias(address *addr1, address *addr2)
{
  return
    (conf.alias_local_cmp(addr1->local_part, addr2->local_part) == 0) &&
    (strcasecmp(addr1->domain, addr2->domain) == 0);
}

static
GList *parse_list(gchar *line)
{
  GList *list = NULL;
  gchar buf[256];
  gchar *p, *q;

  p = line;
  while(*p != 0){
    q = buf;
    while(isspace(*p)) p++;
    if(*p != '\"'){
      while(*p && (*p != ',') && (q < buf+255))
	*(q++) = *(p++);
      *q = 0;
    }else{
      gboolean escape = FALSE;
      p++;
      while(*p && (*p != '\"' || escape) && (q < buf+255)){
	if((*p == '\\') && !escape)
	  escape = TRUE;
	else{
	  escape = FALSE;
	  *(q++) = *p;
	}
	p++;
      }
      *q = 0;
      while(*p && (*p != ',')) p++;
    }
    list = g_list_append(list, g_strdup(g_strchomp(buf)));
    if(*p) p++;
  }
  return list;
}

GList *alias_expand(GList *alias_table, GList *rcpt_list, GList *non_rcpt_list)
{
  GList *done_list = NULL;
  GList *rcpt_node = g_list_copy(rcpt_list);

  while(rcpt_node != NULL){
    address *addr = (address *)(rcpt_node->data);
    DEBUG(5) debugf("alias_expand begin: '%s@%s'\n", addr->local_part, addr->domain);
//    if(addr_is_local(addr) && (addr->local_part[0] != '|') &&
    if(addr_is_local(addr) && 
        !(addr->flags & ADDR_FLAG_NOEXPAND)){
      gchar *val;
      
      /* special handling for postmaster */
      if(strcasecmp(addr->local_part, "postmaster") == 0)
	val = (gchar *)table_find_func(alias_table, addr->local_part, strcasecmp);
      else
	val = (gchar *)table_find_func(alias_table, addr->local_part, conf.alias_local_cmp);

      DEBUG(5) debugf("alias: '%s' is local\n", addr->local_part);
      if(val != NULL){
	GList *val_list = parse_list(val);
	GList *val_node;
	GList *alias_list = NULL;

	DEBUG(5) debugf("alias: '%s' -> '%s'\n", addr->local_part, val);
	foreach(val_list, val_node){
	  gchar *val = (gchar *)(val_node->data);
	  address *alias_addr;
	  address *addr_parent = NULL;

	  if(val[0] == '|'){
	    DEBUG(5) debugf("alias: %s is a pipe address\n", val);
	    alias_addr = create_address_pipe(val);
	    DEBUG(5) debugf("alias_pipe: %s is a pipe address\n", alias_addr->local_part);
	  }else if(val[0] == '\\'){
	    DEBUG(5) debugf("alias: shall not be expanded: '%s'\n", val);
	    alias_addr = create_address_qualified(&(val[1]), TRUE, conf.host_name);
	    alias_addr->flags |= ADDR_FLAG_NOEXPAND;
	    DEBUG(5) debugf("alias: not expanded: '%s'\n",alias_addr->local_part);
	  }else{
	    alias_addr = create_address_qualified(val, TRUE, conf.host_name);

	    /* search in parents for loops: */
	    for(addr_parent = addr; addr_parent; addr_parent = addr_parent->parent){
	      if(addr_isequal_alias(alias_addr, addr_parent)){
		logwrite(LOG_ALERT, "detected alias loop, (ignoring): %s@%s -> %s@%s\n",
			 addr_parent->local_part, addr_parent->domain,
			 addr->local_part, addr->domain);
		break;
	      }
	    }
	  }
	  if(!addr_parent){
	    alias_list = g_list_append(alias_list, alias_addr);
	    alias_addr->parent = addr;
	  }
	  g_free(val);
	}
	g_list_free(val_list);
	addr->children = g_list_copy(alias_list);
	rcpt_node = g_list_concat(rcpt_node, alias_list);
      }else{
	DEBUG(5) debugf("alias: '%s' is completed\n", addr->local_part);
	done_list = g_list_append(done_list, addr);
      }
    }else{
      DEBUG(5) debugf("alias: '%s@%s' is not local\n", addr->local_part, addr->domain);
      done_list = g_list_append(done_list, addr);
    }
    rcpt_node = g_list_next(rcpt_node);
  }

  /* delete addresses from done_list if they are in the non_rcpt_list */
  if(non_rcpt_list){
    GList *rcpt_node_next;
    for(rcpt_node = g_list_first(done_list);
	 rcpt_node;
	 rcpt_node = rcpt_node_next){
      address *addr = (address *)(rcpt_node->data);
      GList *non_node;

      rcpt_node_next = g_list_next(rcpt_node);

      foreach(non_rcpt_list, non_node){
	address *non_addr = (address *)(non_node->data);
	if(addr_isequal(addr, non_addr)){
	  done_list = g_list_remove_link(done_list, rcpt_node);
	  g_list_free_1(rcpt_node);
	  addr_mark_delivered(addr); /* this address is still in the children lists
				      of the original address */
	  break;
	}
      }
    }
  }
  return done_list;
}