/*
 * Copyright (C) 2000,2001	Onlyer	(onlyer@263.net)
 *
 * 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 "common/setup_before.h"
#include "setup.h"

#include <ctype.h>
#ifdef HAVE_STRING_H
# include <string.h>
#else
# ifdef HAVE_STRINGS_H
#  include <strings.h>
# endif
# ifdef HAVE_MEMORY_H
#  include <memory.h>
# endif
#endif
#ifdef STDC_HEADERS
# include <stdlib.h>
#else
# ifdef HAVE_MALLOC_H
#  include <malloc.h>
# endif
#endif
#include "compat/memcpy.h"
#include "compat/strdup.h"
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
# include <sys/socket.h>
#endif
#include "compat/psock.h"
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif
#include "compat/netinet_in.h"
#ifdef HAVE_LIMITS_H
# include <limits.h>
#endif
#include "compat/char_bit.h"
#ifdef TIME_WITH_SYS_TIME
# include <time.h>
# include <sys/time.h>
#else
# ifdef HAVE_SYS_TIME_H
#  include <sys/time.h>
# else
#  include <time.h>
# endif
#endif
#ifdef HAVE_ASSERT_H
# include <assert.h>
#endif

#include "compat/psock.h"
#include "compat/strcasecmp.h"
#include "connection.h"
#include "game.h"
#include "gamequeue.h"
#include "prefs.h"
#include "d2gs.h"
#include "net.h"
#include "s2s.h"
#include "handle_d2gs.h"
#include "handle_d2cs.h"
#include "handle_init.h"
#include "handle_bnetd.h"
#include "d2charfile.h"
#include "common/fdwatch.h"
#include "common/addr.h"
#include "common/introtate.h"
#include "common/network.h"
#include "common/packet.h"
#include "common/hashtable.h"
#include "common/queue.h"
#include "common/eventlog.h"
#include "common/xalloc.h"
#include "common/setup_after.h"

static t_hashtable 	* connlist_head=NULL;
static t_hashtable	* conn_charname_list_head=NULL;
static t_list		* connlist_dead=NULL;
static unsigned int	total_connection=0;

static int conn_handle_connecting(t_connection * c);
static t_packet * conn_create_packet(t_connection * c);
static int conn_handle_packet(t_connection * c, t_packet * packet);
static int conn_handle_read(t_connection * c);
static int conn_handle_write(t_connection * c);
static unsigned int conn_charname_hash(char const * charname);
static unsigned int conn_sessionnum_hash(unsigned int sessionnum);

static unsigned int conn_sessionnum_hash(unsigned int sessionnum)
{
	return sessionnum;
}

static unsigned int conn_charname_hash(char const * charname)
{
	unsigned int hash;
	unsigned int i, len, pos;
	unsigned int ch;

	ASSERT(charname,0);
	len=strlen(charname);
	for (hash=0, i=0, pos=0; i<len; i++) {
		if (isascii((int)charname[i])) {
			ch=(unsigned int)(unsigned char)tolower((int)charname[i]);
		} else {
			ch=(unsigned int)(unsigned char)charname[i];
		}
		hash ^= ROTL(ch,pos,sizeof(unsigned int) * CHAR_BIT);
		pos += CHAR_BIT-1;
	}
	return hash;
}

extern t_hashtable * d2cs_connlist(void)
{
	return connlist_head;
}

extern int d2cs_connlist_create(void)
{
	if (!(connlist_head=hashtable_create(200))) return -1;
	if (!(conn_charname_list_head=hashtable_create(200))) return -1;
	return 0;
}

extern int d2cs_connlist_destroy(void)
{
	t_connection 	* c;
	t_elem		* curr;
	

        if (connlist_dead) {
                d2cs_connlist_reap();
                if (list_destroy(connlist_dead))
                        eventlog(eventlog_level_error,__FUNCTION__,"error destroy conndead list");
                connlist_dead = NULL;
        }

	BEGIN_HASHTABLE_TRAVERSE_DATA(connlist_head, c)
	{
		d2cs_conn_destroy(c,&curr);
	}
	END_HASHTABLE_TRAVERSE_DATA()

	if (hashtable_destroy(connlist_head)<0) {
		eventlog(eventlog_level_error,__FUNCTION__,"error destroy connection list");
		return -1;
	}
	connlist_head=NULL;

	if (hashtable_destroy(conn_charname_list_head)<0) {
		eventlog(eventlog_level_error,__FUNCTION__,"error destroy connection charname list");
		return -1;
	}
	conn_charname_list_head=NULL;
	return 0;
}

extern int d2cs_connlist_reap(void)
{
	t_connection 	* c;
	
	if (!connlist_dead) return 0;
	BEGIN_LIST_TRAVERSE_DATA(connlist_dead, c)
	{
		d2cs_conn_destroy(c,&curr_elem_);
	}
	END_LIST_TRAVERSE_DATA()

	return 0;
}

extern int conn_check_multilogin(t_connection const * c,char const * charname)
{
	t_connection * conn;

	ASSERT(charname,-1);
	if (!prefs_check_multilogin()) return 0;
	if (gamelist_find_character(charname)) {
		return -1;
	}
	conn=d2cs_connlist_find_connection_by_charname(charname);
	if (conn && conn!=c) {
		return -1;
	}
	return 0;
}

extern t_connection * d2cs_connlist_find_connection_by_sessionnum(unsigned int sessionnum)
{
	t_connection 	* c;
	t_entry		* curr;
	unsigned int	hash;

	hash=conn_sessionnum_hash(sessionnum);
	HASHTABLE_TRAVERSE_MATCHING(connlist_head,curr,hash)
	{
		if (!(c=entry_get_data(curr))) {
			eventlog(eventlog_level_error,__FUNCTION__,"got NULL connection in list");
		} else if (c->sessionnum==sessionnum) {
			hashtable_entry_release(curr);
			return c;
		}
	}
	return NULL;
}

extern t_connection * d2cs_connlist_find_connection_by_charname(char const * charname)
{
	t_entry		* curr;
	t_connection 	* c;
	unsigned int	hash;

	hash=conn_charname_hash(charname);
	HASHTABLE_TRAVERSE_MATCHING(connlist_head,curr,hash)
	{
		if (!(c=entry_get_data(curr))) {
			eventlog(eventlog_level_error,__FUNCTION__,"got NULL connection in list");
		} else {
			if (!c->charname) continue;
			if (!strcmp_charname(c->charname,charname)) {
				hashtable_entry_release(curr);
				return c;
			}
		}
	}
	return NULL;
}

static t_packet * conn_create_packet(t_connection * c)
{
	t_packet	* packet;

	switch (c->class) {
		CASE(conn_class_init, packet=packet_create(packet_class_init));
		CASE(conn_class_d2cs, packet=packet_create(packet_class_d2cs));
		CASE(conn_class_d2gs, packet=packet_create(packet_class_d2gs));
		CASE(conn_class_bnetd, packet=packet_create(packet_class_d2cs_bnetd));
		default:
			eventlog(eventlog_level_error,__FUNCTION__,"got bad connection class %d",c->class);
			return NULL;
	}
	if (!packet) {
		eventlog(eventlog_level_error,__FUNCTION__,"error create packet");
		return NULL;
	}
	d2cs_conn_set_in_queue(c,packet);
	return packet;
}

static int conn_handle_connecting(t_connection * c)
{
	int	retval;

	if (net_check_connected(c->sock)<0) {
		eventlog(eventlog_level_warn,__FUNCTION__,"can not connect to %s",addr_num_to_addr_str(c->addr, c->port));
		return -1;
	}
	eventlog(eventlog_level_info,__FUNCTION__,"connected to %s",addr_num_to_addr_str(c->addr, c->port));
	c->state=conn_state_init;
        /* this is a kind of hack to not update fd but updating breaks kqueue
         * and the clean fix would require a cache a userland copy of the kernel
	 * kqueue fds, considering that it also doesnt brake anything else should do
	 * for the moment 
	fdwatch_update_fd(c->sock, fdwatch_type_read); */
	switch (c->class) {
		case conn_class_bnetd:
			retval=handle_bnetd_init(c);
			break;
		default:
			eventlog(eventlog_level_error,__FUNCTION__,"got bad connection class %d",c->class);
			return -1;
	}
	return retval;
}

static int conn_handle_packet(t_connection * c, t_packet * packet)
{
	int	retval;

	switch (c->class) {
		CASE (conn_class_init, retval=d2cs_handle_init_packet(c,packet));
		CASE (conn_class_d2cs, retval=d2cs_handle_d2cs_packet(c,packet));
		CASE (conn_class_d2gs, retval=handle_d2gs_packet(c,packet));
		CASE (conn_class_bnetd, retval=handle_bnetd_packet(c,packet));
		default:
			eventlog(eventlog_level_error,__FUNCTION__,"got bad connection class %d (close connection)",c->class);
			retval=-1;
			break;
	}
	return retval;
}

static int conn_handle_read(t_connection * c)
{
	t_packet	* packet;
	int		retval;

	packet = d2cs_conn_get_in_queue(c);
	if (!packet) {
		packet = conn_create_packet(c);
		if (!packet) return -1;
		c->insize=0;
	}

	switch (net_recv_packet(c->sock,packet,&c->insize)) {
		case -1:
			retval=-1;
			break;
		case 0:
			retval=0;
			break;
		case 1:
			c->insize=0;
			d2cs_conn_set_in_queue(c,NULL);
			retval=conn_handle_packet(c,packet);
			packet_del_ref(packet);
			break;
		default:
			retval=0;
			break;
	}
	return retval;
}

static int conn_handle_write(t_connection * c)
{
	t_packet	* packet;
	int		retval;

	if (c->state==conn_state_connecting) {
		return conn_handle_connecting(c);
	}

	if (!(packet=conn_peek_outqueue(c))) return 0;

	switch (net_send_packet(c->sock, packet, &c->outsize)) {
		case -1:
			retval=-1;
			break;
		case 0:
			retval=0;
			break;
		case 1:
			c->outsize=0;
			packet=conn_pull_outqueue(c);
			packet_del_ref(packet);
			retval=0;
			break;
		default:
			retval = -1;
	}
	return retval;
}

extern int conn_handle_socket(t_connection * c)
{
	time_t	now;

	ASSERT(c,-1);
	now=time(NULL);
	if (c->socket_flag & SOCKET_FLAG_READ) {
		if (conn_handle_read(c)<0) return -1;
		c->last_active=now;
	}
	if (c->socket_flag & SOCKET_FLAG_WRITE) {
		if (conn_handle_write(c)<0) return -1;
		c->last_active=now;
	}
	c->socket_flag=0;
	return 0;
}

extern int connlist_check_timeout(void)
{
	t_connection	* c;
	time_t		now;

	now=time(NULL);
	BEGIN_HASHTABLE_TRAVERSE_DATA(connlist_head, c)
	{
		switch (c->class) {
			case conn_class_d2cs:
				if (prefs_get_idletime() && (now - c->last_active > prefs_get_idletime())) {
					eventlog(eventlog_level_info,__FUNCTION__,"client %d idled too long time, destroy it",c->sessionnum);
					d2cs_conn_set_state(c,conn_state_destroy);
				}
				break;
			case conn_class_d2gs:
				if (prefs_get_s2s_idletime() && now - c->last_active > prefs_get_s2s_idletime()) {
					eventlog(eventlog_level_info,__FUNCTION__,"server %d timed out",c->sessionnum);
					d2cs_conn_set_state(c,conn_state_destroy);
				}
				break;
			case conn_class_bnetd:
				break;
			default:
				break;
		}
	}
	END_HASHTABLE_TRAVERSE_DATA()
	return 0;
}

extern t_connection * d2cs_conn_create(int sock, unsigned int local_addr, unsigned short local_port, 
				unsigned int addr, unsigned short port)
{
	static unsigned int	sessionnum=1;
	t_connection		* c;

	if (sock<0) {
		eventlog(eventlog_level_error,__FUNCTION__,"got bad socket");
		return NULL;
	}
	c=xmalloc(sizeof(t_connection));
	c->charname=NULL;
	c->account=NULL;
	c->sock=sock;
	c->fdw_idx = -1;
	c->socket_flag=0;
	c->local_addr=local_addr;
	c->local_port=local_port;
	c->addr=addr;
	c->port=port;
	c->class=conn_class_init;
	c->state=conn_state_init;
	c->sessionnum=sessionnum++;
	c->outqueue=NULL;
	c->inqueue=NULL;
	c->outsize=0;
	c->outsizep=0;
	c->insize=0;
	c->charinfo=NULL;
	c->d2gs_id=0;
	c->gamequeue=NULL;
	c->last_active=time(NULL);
	c->sessionnum_hash=conn_sessionnum_hash(c->sessionnum);
	c->bnetd_sessionnum=0;
	c->charname_hash=0;
	if (hashtable_insert_data(connlist_head, c, c->sessionnum_hash)<0) {
		xfree(c);
		eventlog(eventlog_level_error,__FUNCTION__,"error add connection to list");
		return NULL;
	}
	total_connection++;
	eventlog(eventlog_level_info,__FUNCTION__,"created session=%d socket=%d (%d current connections)", c->sessionnum, sock, total_connection);
	return c;
}

extern int d2cs_conn_destroy(t_connection * c, t_elem ** curr)
{
	t_elem * elem;

	ASSERT(c,-1);
	if (c->state==conn_state_destroying) return 0;
	if (hashtable_remove_data(connlist_head,c,c->sessionnum_hash)<0) {
		eventlog(eventlog_level_error,__FUNCTION__,"error remove connection from list");
		return -1;
	}
	c->state=conn_state_destroying;
	if (c->d2gs_id && c->class==conn_class_d2gs) {
		d2gs_deactive(d2gslist_find_gs(c->d2gs_id),c);
	}
	if (c->class==conn_class_bnetd) {
		s2s_destroy(c);
	}
	if (c->gamequeue) {
		gq_destroy(c->gamequeue,&elem);
	}
	if (c->account) xfree((void *)c->account);
	if (c->charinfo) xfree((void *)c->charinfo);
	if (c->charname) d2cs_conn_set_charname(c,NULL);
	if (c->inqueue) packet_del_ref(c->inqueue);
	queue_clear(&c->outqueue);

	if (connlist_dead) list_remove_data(connlist_dead, c, curr);
	fdwatch_del_fd(c->fdw_idx);
	psock_shutdown(c->sock,PSOCK_SHUT_RDWR);
	psock_close(c->sock);

	total_connection--;
	eventlog(eventlog_level_info,__FUNCTION__,"[%d] closed connection %d (%d left)",c->sock,c->sessionnum,total_connection);
	xfree(c);
	return 0;
}

extern int d2cs_conn_get_socket(t_connection const * c)
{
	ASSERT(c,-1);
	return c->sock;
}

extern t_conn_state d2cs_conn_get_state(t_connection const * c)
{
	ASSERT(c,conn_state_none);
	return c->state;
}

extern int d2cs_conn_set_state(t_connection * c, t_conn_state state)
{
	t_elem * curr;

	ASSERT(c,-1);
	/* special case for destroying connections, add them to connlist_dead list */
	if (state == conn_state_destroy && c->state != conn_state_destroy) {
	    if (!connlist_dead)
	        connlist_dead = list_create();
	    list_append_data(connlist_dead, c);
	} else if (state != conn_state_destroy && c->state == conn_state_destroy) {
	    if (list_remove_data(connlist_dead, c, &curr)) {
		eventlog(eventlog_level_error, __FUNCTION__, "could not remove dead connection");
		return -1;
	    }
	}
	c->state=state;
	return 0;
}
	
extern t_conn_class d2cs_conn_get_class(t_connection const * c)
{
	ASSERT(c,conn_class_none);
	return c->class;
}

extern int d2cs_conn_set_class(t_connection * c, t_conn_class class)
{
	ASSERT(c,-1);
	c->class=class;
	return 0;
}

extern t_packet * d2cs_conn_get_in_queue(t_connection const * c)
{
	ASSERT(c,NULL);
	return c->inqueue;
}

extern void d2cs_conn_set_in_queue(t_connection * c, t_packet *packet)
{
	assert(c);
	c->inqueue = packet;
}

extern unsigned int d2cs_conn_get_out_size(t_connection const * c)
{
	ASSERT(c,0);
	return c->outsize;
}

extern t_queue * * d2cs_conn_get_out_queue(t_connection const * c)
{
	ASSERT(c,NULL);
	return (t_queue * *)&c->outqueue;
}

extern unsigned int d2cs_conn_get_in_size(t_connection const * c)
{
	ASSERT(c,0);
	return c->insize;
}

extern int conn_push_outqueue(t_connection * c, t_packet * packet)
{
    if (!c)
    {
        eventlog(eventlog_level_error, __FUNCTION__, "got NULL connection");
        return -1;
    }

    if (!packet)
    {
        eventlog(eventlog_level_error, __FUNCTION__, "got NULL packet");
        return -1;
    }

    queue_push_packet((t_queue * *)&c->outqueue, packet);
    if (!c->outsizep++) fdwatch_update_fd(c->fdw_idx, fdwatch_type_read | fdwatch_type_write);

    return 0;
}

extern t_packet * conn_peek_outqueue(t_connection * c)
{
    if (!c)
    {
        eventlog(eventlog_level_error, __FUNCTION__, "got NULL connection");
        return NULL;
    }

    return queue_peek_packet((t_queue const * const *)&c->outqueue);
}

extern t_packet * conn_pull_outqueue(t_connection * c)
{
    if (!c)
    {
        eventlog(eventlog_level_error, __FUNCTION__, "got NULL connection");
        return NULL;
    }

    if (c->outsizep) {
        if (!(--c->outsizep)) fdwatch_update_fd(c->fdw_idx, fdwatch_type_read);
        return queue_pull_packet((t_queue * *)&c->outqueue);
    }

    return NULL;
}

extern int conn_add_socket_flag(t_connection * c, unsigned int flag)
{
	ASSERT(c,-1);
	c->socket_flag |= flag;
	return 0;
}

extern int conn_process_packet(t_connection * c, t_packet * packet, t_packet_handle_table * table,
				unsigned int table_size)
{
        unsigned int     type;
        unsigned int     size;

	ASSERT(c,-1);
        ASSERT(packet,-1);
	ASSERT(table,-1);
        type=packet_get_type(packet);
        size=packet_get_size(packet);

        if (type >= table_size || !table[type].size) {
		eventlog(eventlog_level_error,__FUNCTION__,"got bad packet type %d (class %d)",type,packet_get_class(packet));
		return -1;
	}
	if (size < table[type].size) {
		eventlog(eventlog_level_error,__FUNCTION__,"got bad packet size %d (type %d class %d)",size,type,packet_get_class(packet));
		return -1;
	}
	if (!(c->state & table[type].state)) {
		eventlog(eventlog_level_error,__FUNCTION__,"connection %d state mismatch for packet type %d (class %d)",c->sessionnum,
			type,packet_get_class(packet));
		return -1;
	}
	if (!table[type].handler) {
		eventlog(eventlog_level_error,__FUNCTION__,"missing handler for packet type %d (class %d)",type,packet_get_class(packet));
		return -1;
	}
	return table[type].handler(c,packet);
}

extern int d2cs_conn_set_account(t_connection * c, char const * account)
{
	ASSERT(c,-1);
	if (!account) {
		if (c->account) xfree((void *)c->account);
		c->account=NULL;
	}
	if (c->account) xfree((void *)c->account);
	c->account=xstrdup(account);

	return 0;
}

extern char const * d2cs_conn_get_account(t_connection const * c)
{
	ASSERT(c,NULL);
	return c->account;
}

extern int d2cs_conn_set_charname(t_connection * c, char const * charname)
{
	char const	* temp;

	ASSERT(c,-1);
	temp=NULL;
	if (charname) temp=xstrdup(charname);
	if (c->charname) {
		if (hashtable_remove_data(conn_charname_list_head,c,c->charname_hash) <0) {
			eventlog(eventlog_level_error,__FUNCTION__,"error remove charname %s from list",charname);
			if (temp) xfree((void *)temp);
			return -1;
		}
		hashtable_purge(conn_charname_list_head);
		xfree((void *)c->charname);
	}
	if (charname) {
		c->charname=temp;
		c->charname_hash=conn_charname_hash(charname);
		if (hashtable_insert_data(conn_charname_list_head,c,c->charname_hash) <0) {
			eventlog(eventlog_level_error,__FUNCTION__,"error insert charname %s to list",charname);
			xfree((void *)c->charname);
			c->charname=NULL;
			return -1;
		}
	} else {
		c->charname=NULL;
		c->charname_hash=0;
	}
	return 0;
}

extern char const * d2cs_conn_get_charname(t_connection const * c)
{
	ASSERT(c,NULL);
	return c->charname;
}

extern unsigned int d2cs_conn_get_sessionnum(t_connection const * c)
{
	ASSERT(c,0);
	return c->sessionnum;
}

extern unsigned int conn_get_charinfo_ladder(t_connection const * c)
{
	ASSERT(c,0);
	return d2charinfo_get_ladder(c->charinfo);
}

extern unsigned int conn_get_charinfo_expansion(t_connection const * c)
{
	ASSERT(c,0);
	return d2charinfo_get_expansion(c->charinfo);
}

extern unsigned int conn_get_charinfo_hardcore(t_connection const * c)
{
	ASSERT(c,0);
	return d2charinfo_get_hardcore(c->charinfo);
}

extern unsigned int conn_get_charinfo_dead(t_connection const * c)
{
	ASSERT(c,0);
	return d2charinfo_get_dead(c->charinfo);
}

extern unsigned int conn_get_charinfo_difficulty(t_connection const * c)
{
	ASSERT(c,0);
	return d2charinfo_get_difficulty(c->charinfo);
}

extern unsigned int conn_get_charinfo_level(t_connection const * c)
{
	ASSERT(c,0);
	return d2charinfo_get_level(c->charinfo);
}

extern unsigned int conn_get_charinfo_class(t_connection const * c)
{
	ASSERT(c,0);
	return d2charinfo_get_class(c->charinfo);
}

extern int conn_set_charinfo(t_connection * c, t_d2charinfo_summary const * charinfo)
{
	ASSERT(c,-1);
	if (!charinfo) {
		if (c->charinfo) xfree((void *)c->charinfo);
		c->charinfo=NULL;
		return 0;
	}
	if (c->charinfo) xfree((void *)c->charinfo);
	c->charinfo=xmalloc(sizeof(t_d2charinfo_summary));
	memcpy((void*)c->charinfo,charinfo,sizeof(t_d2charinfo_summary));
	return 0;
}

extern int conn_set_d2gs_id(t_connection * c, unsigned int d2gs_id)
{
	ASSERT(c,-1)
	c->d2gs_id=d2gs_id;
	return 0;
}

extern unsigned int conn_get_d2gs_id(t_connection const * c)
{
	ASSERT(c,0)
	return c->d2gs_id;
}

extern unsigned int d2cs_conn_get_addr(t_connection const * c)
{
	ASSERT(c,0);
	return c->addr;
}

extern unsigned short d2cs_conn_get_port(t_connection const * c)
{
	ASSERT(c,0);
	return c->port;
}

extern t_gq * conn_get_gamequeue(t_connection const * c)
{
	ASSERT(c,NULL);
	return c->gamequeue;
}

extern int conn_set_gamequeue(t_connection * c, t_gq * gq)
{
	ASSERT(c,-1);
	c->gamequeue=gq;
	return 0;
}

extern int conn_set_bnetd_sessionnum(t_connection * c, unsigned int sessionnum)
{
	ASSERT(c,-1);
	c->bnetd_sessionnum=sessionnum;
	return 0;
}

extern unsigned int conn_get_bnetd_sessionnum(t_connection const * c)
{
	ASSERT(c,0);
	return c->bnetd_sessionnum;
}

extern int conn_add_fd(t_connection * c, t_fdwatch_type rw, fdwatch_handler handler)
{
	assert(c);
	c->fdw_idx = fdwatch_add_fd(c->sock,rw,handler,c);
	return c->fdw_idx;
}