/*
 * Copyright (C) 1997-2001 Id Software, Inc.
 *
 * 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.
 *
 * =======================================================================
 *
 * Server main function and correspondig stuff
 *
 * =======================================================================
 */

#include "header/server.h"

#define HEARTBEAT_SECONDS   300

netadr_t master_adr [ MAX_MASTERS ]; /* address of group servers */

client_t    *sv_client;         /* current client */

cvar_t  *sv_paused;
cvar_t  *sv_timedemo;
cvar_t  *sv_enforcetime;
cvar_t  *timeout;               /* seconds without any message */
cvar_t  *zombietime;            /* seconds to sink messages after disconnect */
cvar_t  *rcon_password;         /* password for remote server commands */
cvar_t  *allow_download;
cvar_t  *allow_download_players;
cvar_t  *allow_download_models;
cvar_t  *allow_download_sounds;
cvar_t  *allow_download_maps;
cvar_t  *sv_airaccelerate;
cvar_t  *sv_noreload;           /* don't reload level state when reentering */
cvar_t  *maxclients;            /* FIXME: rename sv_maxclients */
cvar_t  *sv_showclamp;
cvar_t  *hostname;
cvar_t  *public_server;         /* should heartbeats be sent */

void Master_Shutdown ( void );
void SV_ConnectionlessPacket ( void );

/*
 * Called when the player is totally leaving the server, either willingly
 * or unwillingly.  This is NOT called if the entire server is quiting
 * or crashing.
 */
void
SV_DropClient ( client_t *drop )
{
	/* add the disconnect */
	MSG_WriteByte( &drop->netchan.message, svc_disconnect );

	if ( drop->state == cs_spawned )
	{
		/* call the prog function for removing a client
		   this will remove the body, among other things */
		ge->ClientDisconnect( drop->edict );
	}

	if ( drop->download )
	{
		FS_FreeFile( drop->download );
		drop->download = NULL;
	}

	drop->state = cs_zombie; /* become free in a few seconds */
	drop->name [ 0 ] = 0;
}

/*
 * Builds the string that is sent as heartbeats and status replies
 */
char *
SV_StatusString ( void )
{
	char player [ 1024 ];
	static char status [ MAX_MSGLEN - 16 ];
	int i;
	client_t    *cl;
	int statusLength;
	int playerLength;

	strcpy( status, Cvar_Serverinfo() );
	strcat( status, "\n" );
	statusLength = (int) strlen( status );

	for ( i = 0; i < maxclients->value; i++ )
	{
		cl = &svs.clients [ i ];

		if ( ( cl->state == cs_connected ) || ( cl->state == cs_spawned ) )
		{
			Com_sprintf( player, sizeof ( player ), "%i %i \"%s\"\n",
					cl->edict->client->ps.stats [ STAT_FRAGS ], cl->ping, cl->name );
			playerLength = (int) strlen( player );

			if ( statusLength + playerLength >= sizeof ( status ) )
			{
				break; /* can't hold any more */
			}

			strcpy( status + statusLength, player );
			statusLength += playerLength;
		}
	}

	return ( status );
}

/*
 * Updates the cl->ping variables
 */
void
SV_CalcPings ( void )
{
	int i, j;
	client_t    *cl;
	int total, count;

	for ( i = 0; i < maxclients->value; i++ )
	{
		cl = &svs.clients [ i ];

		if ( cl->state != cs_spawned )
		{
			continue;
		}

		total = 0;
		count = 0;

		for ( j = 0; j < LATENCY_COUNTS; j++ )
		{
			if ( cl->frame_latency [ j ] > 0 )
			{
				count++;
				total += cl->frame_latency [ j ];
			}
		}

		if ( !count )
		{
			cl->ping = 0;
		}
		else
		{
			cl->ping = total / count;
		}

		/* let the game dll know about the ping */
		cl->edict->client->ping = cl->ping;
	}
}

/*
 * Every few frames, gives all clients an allotment of milliseconds
 * for their command moves. If they exceed it, assume cheating.
 */
void
SV_GiveMsec ( void )
{
	int i;
	client_t    *cl;

	if ( sv.framenum & 15 )
	{
		return;
	}

	for ( i = 0; i < maxclients->value; i++ )
	{
		cl = &svs.clients [ i ];

		if ( cl->state == cs_free )
		{
			continue;
		}

		cl->commandMsec = 1800; /* 1600 + some slop */
	}
}

void
SV_ReadPackets ( void )
{
	int i;
	client_t    *cl;
	int qport;

	while ( NET_GetPacket( NS_SERVER, &net_from, &net_message ) )
	{
		/* check for connectionless packet (0xffffffff) first */
		if ( *(int *) net_message.data == -1 )
		{
			SV_ConnectionlessPacket();
			continue;
		}

		/* read the qport out of the message so we can fix up
		   stupid address translating routers */
		MSG_BeginReading( &net_message );
		MSG_ReadLong( &net_message );        /* sequence number */
		MSG_ReadLong( &net_message );        /* sequence number */
		qport = MSG_ReadShort( &net_message ) & 0xffff;

		/* check for packets from connected clients */
		for ( i = 0, cl = svs.clients; i < maxclients->value; i++, cl++ )
		{
			if ( cl->state == cs_free )
			{
				continue;
			}

			if ( !NET_CompareBaseAdr( net_from, cl->netchan.remote_address ) )
			{
				continue;
			}

			if ( cl->netchan.qport != qport )
			{
				continue;
			}

			if ( cl->netchan.remote_address.port != net_from.port )
			{
				Com_Printf( "SV_ReadPackets: fixing up a translated port\n" );
				cl->netchan.remote_address.port = net_from.port;
			}

			if ( Netchan_Process( &cl->netchan, &net_message ) )
			{
				/* this is a valid, sequenced packet, so process it */
				if ( cl->state != cs_zombie )
				{
					cl->lastmessage = svs.realtime; /* don't timeout */

					if ( !( sv.demofile && ( sv.state == ss_demo ) ) )
					{
						SV_ExecuteClientMessage( cl );
					}
				}
			}

			break;
		}

		if ( i != maxclients->value )
		{
			continue;
		}
	}
}

/*
 * If a packet has not been received from a client for timeout->value
 * seconds, drop the conneciton.  Server frames are used instead of
 * realtime to avoid dropping the local client while debugging.
 *
 * When a client is normally dropped, the client_t goes into a zombie state
 * for a few seconds to make sure any final reliable message gets resent
 * if necessary
 */
void
SV_CheckTimeouts ( void )
{
	int i;
	client_t    *cl;
	int droppoint;
	int zombiepoint;

	droppoint = svs.realtime - 1000 * timeout->value;
	zombiepoint = svs.realtime - 1000 * zombietime->value;

	for ( i = 0, cl = svs.clients; i < maxclients->value; i++, cl++ )
	{
		/* message times may be wrong across a changelevel */
		if ( cl->lastmessage > svs.realtime )
		{
			cl->lastmessage = svs.realtime;
		}

		if ( ( cl->state == cs_zombie ) &&
			 ( cl->lastmessage < zombiepoint ) )
		{
			cl->state = cs_free; /* can now be reused */
			continue;
		}

		if ( ( ( cl->state == cs_connected ) || ( cl->state == cs_spawned ) ) &&
			 ( cl->lastmessage < droppoint ) )
		{
			SV_BroadcastPrintf( PRINT_HIGH, "%s timed out\n", cl->name );
			SV_DropClient( cl );
			cl->state = cs_free; /* don't bother with zombie state */
		}
	}
}

/*
 * This has to be done before the world logic, because
 * player processing happens outside RunWorldFrame
 */
void
SV_PrepWorldFrame ( void )
{
	edict_t *ent;
	int i;

	for ( i = 0; i < ge->num_edicts; i++, ent++ )
	{
		ent = EDICT_NUM( i );

		/* events only last for a single message */
		ent->s.event = 0;
	}
}

void
SV_RunGameFrame ( void )
{
#ifndef DEDICATED_ONLY

	if ( host_speeds->value )
	{
		time_before_game = Sys_Milliseconds();
	}

#endif

	/* we always need to bump framenum, even if we
	   don't run the world, otherwise the delta
	   compression can get confused when a client
	   has the "current" frame */
	sv.framenum++;
	sv.time = sv.framenum * 100;

	/* don't run if paused */
	if ( !sv_paused->value || ( maxclients->value > 1 ) )
	{
		ge->RunFrame();

		/* never get more than one tic behind */
		if ( sv.time < svs.realtime )
		{
			if ( sv_showclamp->value )
			{
				Com_Printf( "sv highclamp\n" );
			}

			svs.realtime = sv.time;
		}
	}

#ifndef DEDICATED_ONLY

	if ( host_speeds->value )
	{
		time_after_game = Sys_Milliseconds();
	}

#endif
}

void
SV_Frame ( int msec )
{
#ifndef DEDICATED_ONLY
	time_before_game = time_after_game = 0;
#endif

	/* if server is not active, do nothing */
	if ( !svs.initialized )
	{
		return;
	}

	svs.realtime += msec;

	/* keep the random time dependent */
	randk();

	/* check timeouts */
	SV_CheckTimeouts();

	/* get packets from clients */
	SV_ReadPackets();

	/* move autonomous things around if enough time has passed */
	if ( !sv_timedemo->value && ( svs.realtime < sv.time ) )
	{
		/* never let the time get too far off */
		if ( sv.time - svs.realtime > 100 )
		{
			if ( sv_showclamp->value )
			{
				Com_Printf( "sv lowclamp\n" );
			}

			svs.realtime = sv.time - 100;
		}

		NET_Sleep( sv.time - svs.realtime );
		return;
	}

	/* update ping based on the last known frame from all clients */
	SV_CalcPings();

	/* give the clients some timeslices */
	SV_GiveMsec();

	/* let everything in the world think and move */
	SV_RunGameFrame();

	/* send messages back to the clients that had packets read this frame */
	SV_SendClientMessages();

	/* save the entire world state if recording a serverdemo */
	SV_RecordDemoMessage();

	/* send a heartbeat to the master if needed */
	Master_Heartbeat();

	/* clear teleport flags, etc for next frame */
	SV_PrepWorldFrame();
}

/*
 * Send a message to the master every few minutes to
 * let it know we are alive, and log information
 */
void
Master_Heartbeat ( void )
{
	char        *string;
	int i;

	if ( !dedicated || !dedicated->value )
	{
		return; /* only dedicated servers send heartbeats */
	}

	if ( !public_server || !public_server->value )
	{
		return; /* a private dedicated game */
	}

	/* check for time wraparound */
	if ( svs.last_heartbeat > svs.realtime )
	{
		svs.last_heartbeat = svs.realtime;
	}

	if ( svs.realtime - svs.last_heartbeat < HEARTBEAT_SECONDS * 1000 )
	{
		return; /* not time to send yet */
	}

	svs.last_heartbeat = svs.realtime;

	/* send the same string that we would give for a status OOB command */
	string = SV_StatusString();

	/* send to group master */
	for ( i = 0; i < MAX_MASTERS; i++ )
	{
		if ( master_adr [ i ].port )
		{
			Com_Printf( "Sending heartbeat to %s\n", NET_AdrToString( master_adr [ i ] ) );
			Netchan_OutOfBandPrint( NS_SERVER, master_adr [ i ], "heartbeat\n%s", string );
		}
	}
}

/*
 * Informs all masters that this server is going down
 */
void
Master_Shutdown ( void )
{
	int i;

	if ( !dedicated || !dedicated->value )
	{
		return; /* only dedicated servers send heartbeats */
	}

	if ( !public_server || !public_server->value )
	{
		return; /* a private dedicated game */
	}

	/* send to group master */
	for ( i = 0; i < MAX_MASTERS; i++ )
	{
		if ( master_adr [ i ].port )
		{
			if ( i > 0 )
			{
				Com_Printf( "Sending heartbeat to %s\n", NET_AdrToString( master_adr [ i ] ) );
			}

			Netchan_OutOfBandPrint( NS_SERVER, master_adr [ i ], "shutdown" );
		}
	}
}

/*
 * Pull specific info from a newly changed userinfo string
 * into a more C freindly form.
 */
void
SV_UserinfoChanged ( client_t *cl )
{
	char    *val;
	int i;

	/* call prog code to allow overrides */
	ge->ClientUserinfoChanged( cl->edict, cl->userinfo );

	/* name for C code */
	strncpy( cl->name, Info_ValueForKey( cl->userinfo, "name" ), sizeof ( cl->name ) - 1 );

	/* mask off high bit */
	for ( i = 0; i < sizeof ( cl->name ); i++ )
	{
		cl->name [ i ] &= 127;
	}

	/* rate command */
	val = Info_ValueForKey( cl->userinfo, "rate" );

	if ( strlen( val ) )
	{
		i = (int)strtol( val, (char **)NULL, 10 );
		cl->rate = i;

		if ( cl->rate < 100 )
		{
			cl->rate = 100;
		}

		if ( cl->rate > 15000 )
		{
			cl->rate = 15000;
		}
	}
	else
	{
		cl->rate = 5000;
	}

	/* msg command */
	val = Info_ValueForKey( cl->userinfo, "msg" );

	if ( strlen( val ) )
	{
		cl->messagelevel = (int)strtol( val, (char **)NULL, 10 );
	}
}

/*
 * Only called at quake2.exe startup, not for each game
 */
void
SV_Init ( void )
{
	SV_InitOperatorCommands();

	rcon_password = Cvar_Get( "rcon_password", "", 0 );
	Cvar_Get( "skill", "1", 0 );
	Cvar_Get( "deathmatch", "0", CVAR_LATCH );
	Cvar_Get( "coop", "0", CVAR_LATCH );
	Cvar_Get( "dmflags", va( "%i", DF_INSTANT_ITEMS ), CVAR_SERVERINFO );
	Cvar_Get( "fraglimit", "0", CVAR_SERVERINFO );
	Cvar_Get( "timelimit", "0", CVAR_SERVERINFO );
	Cvar_Get( "cheats", "0", CVAR_SERVERINFO | CVAR_LATCH );
	Cvar_Get( "protocol", va( "%i", PROTOCOL_VERSION ), CVAR_SERVERINFO | CVAR_NOSET );
	maxclients = Cvar_Get( "maxclients", "1", CVAR_SERVERINFO | CVAR_LATCH );
	hostname = Cvar_Get( "hostname", "noname", CVAR_SERVERINFO | CVAR_ARCHIVE );
	timeout = Cvar_Get( "timeout", "125", 0 );
	zombietime = Cvar_Get( "zombietime", "2", 0 );
	sv_showclamp = Cvar_Get( "showclamp", "0", 0 );
	sv_paused = Cvar_Get( "paused", "0", 0 );
	sv_timedemo = Cvar_Get( "timedemo", "0", 0 );
	sv_enforcetime = Cvar_Get( "sv_enforcetime", "0", 0 );
	allow_download = Cvar_Get( "allow_download", "1", CVAR_ARCHIVE );
	allow_download_players  = Cvar_Get( "allow_download_players", "0", CVAR_ARCHIVE );
	allow_download_models = Cvar_Get( "allow_download_models", "1", CVAR_ARCHIVE );
	allow_download_sounds = Cvar_Get( "allow_download_sounds", "1", CVAR_ARCHIVE );
	allow_download_maps   = Cvar_Get( "allow_download_maps", "1", CVAR_ARCHIVE );

	sv_noreload = Cvar_Get( "sv_noreload", "0", 0 );

	sv_airaccelerate = Cvar_Get( "sv_airaccelerate", "0", CVAR_LATCH );

	public_server = Cvar_Get( "public", "0", 0 );

	SZ_Init( &net_message, net_message_buffer, sizeof ( net_message_buffer ) );
}

/*
 * Used by SV_Shutdown to send a final message to all
 * connected clients before the server goes down. The messages are sent immediately,
 * not just stuck on the outgoing message list, because the server is going
 * to totally exit after returning from this function.
 */
void
SV_FinalMessage ( char *message, qboolean reconnect )
{
	int i;
	client_t    *cl;

	SZ_Clear( &net_message );
	MSG_WriteByte( &net_message, svc_print );
	MSG_WriteByte( &net_message, PRINT_HIGH );
	MSG_WriteString( &net_message, message );

	if ( reconnect )
	{
		MSG_WriteByte( &net_message, svc_reconnect );
	}
	else
	{
		MSG_WriteByte( &net_message, svc_disconnect );
	}

	/* stagger the packets to crutch operating system limited buffers */
	for ( i = 0, cl = svs.clients; i < maxclients->value; i++, cl++ )
	{
		if ( cl->state >= cs_connected )
		{
			Netchan_Transmit( &cl->netchan, net_message.cursize, net_message.data );
		}
	}

	for ( i = 0, cl = svs.clients; i < maxclients->value; i++, cl++ )
	{
		if ( cl->state >= cs_connected )
		{
			Netchan_Transmit( &cl->netchan, net_message.cursize,
					net_message.data );
		}
	}
}

/*
 * Called when each game quits,
 * before Sys_Quit or Sys_Error
 */
void
SV_Shutdown ( char *finalmsg, qboolean reconnect )
{
	if ( svs.clients )
	{
		SV_FinalMessage( finalmsg, reconnect );
	}

	Master_Shutdown();
	SV_ShutdownGameProgs();

	/* free current level */
	if ( sv.demofile )
	{
		FS_FCloseFile( (size_t) sv.demofile );
	}

	memset( &sv, 0, sizeof ( sv ) );
	Com_SetServerState( sv.state );

	/* free server static data */
	if ( svs.clients )
	{
		Z_Free( svs.clients );
	}

	if ( svs.client_entities )
	{
		Z_Free( svs.client_entities );
	}

	if ( svs.demofile )
	{
		FS_FCloseFile( (size_t) svs.demofile );
	}

	memset( &svs, 0, sizeof ( svs ) );
}