/*
Copyright (C) 1996-2001 Id Software, Inc.
Copyright (C) 2002-2009 John Fitzgibbons and others
Copyright (C) 2010-2014 QuakeSpasm developers

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.

*/
// sv_user.c -- server code for moving users

#include "q_defs.h"

edict_t *sv_player;

extern  cvar_t  sv_friction;
cvar_t  sv_edgefriction = {"edgefriction", "2", CVAR_NONE};
extern  cvar_t  sv_stopspeed;

static  vec3_t          forward, right, up;

// world
float   *angles;
float   *origin;
float   *velocity;

bool    onground;

usercmd_t       cmd;

cvar_t  sv_idealpitchscale = {"sv_idealpitchscale", "0.8", CVAR_NONE};
cvar_t  sv_altnoclip = {"sv_altnoclip", "1", CVAR_ARCHIVE}; //johnfitz

/*
===============
SV_SetIdealPitch
===============
*/
#define MAX_FORWARD     6
void SV_SetIdealPitch(void)
{
	float   angleval, sinval, cosval;
	trace_t tr;
	vec3_t  top, bottom;
	float   z[MAX_FORWARD];
	int32_t         i, j;
	int32_t         step, dir, steps;

	if(!((int32_t)ED_Float(sv_player, ED_flags) & FL_ONGROUND))
		return;

	angleval = ED_Vector(sv_player, ED_angles)[YAW] * PI * 2 / 360;
	sinval = sin(angleval);
	cosval = cos(angleval);

	for(i = 0 ; i < MAX_FORWARD ; i++)
	{
		top[0] = ED_Vector(sv_player, ED_origin)[0] + cosval * (i + 3) * 12;
		top[1] = ED_Vector(sv_player, ED_origin)[1] + sinval * (i + 3) * 12;
		top[2] = ED_Vector(sv_player, ED_origin)[2] + ED_Vector(sv_player, ED_view_ofs)[2];

		bottom[0] = top[0];
		bottom[1] = top[1];
		bottom[2] = top[2] - 160;

		tr = SV_Move(top, vec3_origin, vec3_origin, bottom, 1, sv_player);
		if(tr.allsolid)
			return; // looking at a wall, leave ideal the way is was

		if(tr.fraction == 1)
			return; // near a dropoff

		z[i] = top[2] + tr.fraction * (bottom[2] - top[2]);
	}

	dir = 0;
	steps = 0;
	for(j = 1 ; j < i ; j++)
	{
		step = z[j] - z[j - 1];
		if(step > -ON_EPSILON && step < ON_EPSILON)
			continue;

		if(dir && (step - dir > ON_EPSILON || step - dir < -ON_EPSILON))
			return;         // mixed changes

		steps++;
		dir = step;
	}

	if(!dir)
	{
		ED_Float(sv_player, ED_idealpitch) = 0;
		return;
	}

	if(steps < 2)
		return;
	ED_Float(sv_player, ED_idealpitch) = -dir * sv_idealpitchscale.value;
}


/*
==================
SV_UserFriction

==================
*/
void SV_UserFriction(void)
{
	float   *vel;
	float   speed, newspeed, control;
	vec3_t  start, stop;
	float   friction;
	trace_t trace;

	vel = velocity;

	speed = sqrt(vel[0] * vel[0] + vel[1] * vel[1]);
	if(!speed)
		return;

// if the leading edge is over a dropoff, increase friction
	start[0] = stop[0] = origin[0] + vel[0] / speed * 16;
	start[1] = stop[1] = origin[1] + vel[1] / speed * 16;
	start[2] = origin[2] + ED_Vector(sv_player, ED_mins)[2];
	stop[2] = start[2] - 34;

	trace = SV_Move(start, vec3_origin, vec3_origin, stop, true, sv_player);

	if(trace.fraction == 1.0)
		friction = sv_friction.value * sv_edgefriction.value;
	else
		friction = sv_friction.value;

// apply friction
	control = speed < sv_stopspeed.value ? sv_stopspeed.value : speed;
	newspeed = speed - host_frametime * control * friction;

	if(newspeed < 0)
		newspeed = 0;
	newspeed /= speed;

	vel[0] = vel[0] * newspeed;
	vel[1] = vel[1] * newspeed;
	vel[2] = vel[2] * newspeed;
}

/*
==============
SV_Accelerate
==============
*/
cvar_t  sv_maxspeed = {"sv_maxspeed", "320", CVAR_NOTIFY | CVAR_SERVERINFO};
cvar_t  sv_accelerate = {"sv_accelerate", "10", CVAR_NONE};
void SV_Accelerate(float wishspeed, const vec3_t wishdir)
{
	int32_t                 i;
	float           addspeed, accelspeed, currentspeed;

	currentspeed = DotProduct(velocity, wishdir);
	addspeed = wishspeed - currentspeed;
	if(addspeed <= 0)
		return;
	accelspeed = sv_accelerate.value * host_frametime * wishspeed;
	if(accelspeed > addspeed)
		accelspeed = addspeed;

	for(i = 0 ; i < 3 ; i++)
		velocity[i] += accelspeed * wishdir[i];
}

void SV_AirAccelerate(float wishspeed, vec3_t wishveloc)
{
	int32_t                 i;
	float           addspeed, wishspd, accelspeed, currentspeed;

	wishspd = VectorNormalize(wishveloc);
	if(wishspd > 30)
		wishspd = 30;
	currentspeed = DotProduct(velocity, wishveloc);
	addspeed = wishspd - currentspeed;
	if(addspeed <= 0)
		return;
//	accelspeed = sv_accelerate.value * host_frametime;
	accelspeed = sv_accelerate.value * wishspeed * host_frametime;
	if(accelspeed > addspeed)
		accelspeed = addspeed;

	for(i = 0 ; i < 3 ; i++)
		velocity[i] += accelspeed * wishveloc[i];
}


void DropPunchAngle(void)
{
	float   len;

	len = VectorNormalize(ED_Vector(sv_player, ED_punchangle));

	len -= 10 * host_frametime;
	if(len < 0)
		len = 0;
	VectorScale(ED_Vector(sv_player, ED_punchangle), len, ED_Vector(sv_player, ED_punchangle));
}

/*
===================
SV_WaterMove

===================
*/
void SV_WaterMove(void)
{
	int32_t         i;
	vec3_t  wishvel;
	float   speed, newspeed, wishspeed, addspeed, accelspeed;

//
// user intentions
//
	AngleVectors(ED_Vector(sv_player, ED_v_angle), forward, right, up);

	for(i = 0 ; i < 3 ; i++)
		wishvel[i] = forward[i] * cmd.forwardmove + right[i] * cmd.sidemove;

	if(!cmd.forwardmove && !cmd.sidemove && !cmd.upmove)
		wishvel[2] -= 60;               // drift towards bottom
	else
		wishvel[2] += cmd.upmove;

	wishspeed = VectorLength(wishvel);
	if(wishspeed > sv_maxspeed.value)
	{
		VectorScale(wishvel, sv_maxspeed.value / wishspeed, wishvel);
		wishspeed = sv_maxspeed.value;
	}
	wishspeed *= 0.7;

//
// water friction
//
	speed = VectorLength(velocity);
	if(speed)
	{
		newspeed = speed - host_frametime * speed * sv_friction.value;
		if(newspeed < 0)
			newspeed = 0;
		VectorScale(velocity, newspeed / speed, velocity);
	}
	else
		newspeed = 0;

//
// water acceleration
//
	if(!wishspeed)
		return;

	addspeed = wishspeed - newspeed;
	if(addspeed <= 0)
		return;

	VectorNormalize(wishvel);
	accelspeed = sv_accelerate.value * wishspeed * host_frametime;
	if(accelspeed > addspeed)
		accelspeed = addspeed;

	for(i = 0 ; i < 3 ; i++)
		velocity[i] += accelspeed * wishvel[i];
}

void SV_WaterJump(void)
{
	if(sv.time > ED_Float(sv_player, ED_teleport_time)
	                || !ED_Float(sv_player, ED_waterlevel))
	{
		ED_Float(sv_player, ED_flags) = (int32_t)ED_Float(sv_player, ED_flags) & ~FL_WATERJUMP;
		ED_Float(sv_player, ED_teleport_time) = 0;
	}
	ED_Vector(sv_player, ED_velocity)[0] = ED_Vector(sv_player, ED_movedir)[0];
	ED_Vector(sv_player, ED_velocity)[1] = ED_Vector(sv_player, ED_movedir)[1];
}

/*
===================
SV_NoclipMove -- johnfitz

new, alternate noclip. old noclip is still handled in SV_AirMove
===================
*/
void SV_NoclipMove(void)
{
	AngleVectors(ED_Vector(sv_player, ED_v_angle), forward, right, up);

	velocity[0] = forward[0] * cmd.forwardmove + right[0] * cmd.sidemove;
	velocity[1] = forward[1] * cmd.forwardmove + right[1] * cmd.sidemove;
	velocity[2] = forward[2] * cmd.forwardmove + right[2] * cmd.sidemove;
	velocity[2] += cmd.upmove * 2; //doubled to match running speed

	if(VectorLength(velocity) > sv_maxspeed.value)
	{
		VectorNormalize(velocity);
		VectorScale(velocity, sv_maxspeed.value, velocity);
	}
}

/*
===================
SV_AirMove
===================
*/
void SV_AirMove(void)
{
	int32_t                 i;
	vec3_t          wishvel, wishdir;
	float           wishspeed;
	float           fmove, smove;

	AngleVectors(ED_Vector(sv_player, ED_angles), forward, right, up);

	fmove = cmd.forwardmove;
	smove = cmd.sidemove;

// hack to not let you back into teleporter
	if(sv.time < ED_Float(sv_player, ED_teleport_time) && fmove < 0)
		fmove = 0;

	for(i = 0 ; i < 3 ; i++)
		wishvel[i] = forward[i] * fmove + right[i] * smove;

	if((int32_t)ED_Float(sv_player, ED_movetype) != MOVETYPE_WALK)
		wishvel[2] = cmd.upmove;
	else
		wishvel[2] = 0;

	VectorCopy(wishvel, wishdir);
	wishspeed = VectorNormalize(wishdir);
	if(wishspeed > sv_maxspeed.value)
	{
		VectorScale(wishvel, sv_maxspeed.value / wishspeed, wishvel);
		wishspeed = sv_maxspeed.value;
	}

	if(ED_Float(sv_player, ED_movetype) == MOVETYPE_NOCLIP)
	{
		// noclip
		VectorCopy(wishvel, velocity);
	}
	else if(onground)
	{
		SV_UserFriction();
		SV_Accelerate(wishspeed, wishdir);
	}
	else
	{
		// not on ground, so little effect on velocity
		SV_AirAccelerate(wishspeed, wishvel);
	}
}

/*
===================
SV_ClientThink

moves specify an intended velocity in pix/sec
angles specify an exact angular motion in degrees
===================
*/
void SV_ClientThink(void)
{
	vec3_t          v_angle;

	if(ED_Float(sv_player, ED_movetype) == MOVETYPE_NONE)
		return;

	onground = (int32_t)ED_Float(sv_player, ED_flags) & FL_ONGROUND;

	origin = ED_Vector(sv_player, ED_origin);
	velocity = ED_Vector(sv_player, ED_velocity);

	DropPunchAngle();

//
// if dead, behave differently
//
	if(ED_Float(sv_player, ED_health) <= 0)
		return;

//
// angles
// show 1/3 the pitch angle and all the roll angle
	cmd = host_client->cmd;
	angles = ED_Vector(sv_player, ED_angles);

	VectorAdd(ED_Vector(sv_player, ED_v_angle), ED_Vector(sv_player, ED_punchangle), v_angle);
	angles[ROLL] = V_CalcRoll(ED_Vector(sv_player, ED_angles), ED_Vector(sv_player, ED_velocity)) * 4;
	if(!ED_Float(sv_player, ED_fixangle))
	{
		angles[PITCH] = -v_angle[PITCH] / 3;
		angles[YAW] = v_angle[YAW];
	}

	if((int32_t)ED_Float(sv_player, ED_flags) & FL_WATERJUMP)
	{
		SV_WaterJump();
		return;
	}
//
// walk
//
	//johnfitz -- alternate noclip
	if(ED_Float(sv_player, ED_movetype) == MOVETYPE_NOCLIP && sv_altnoclip.value)
		SV_NoclipMove();
	else if(ED_Float(sv_player, ED_waterlevel) >= 2 && ED_Float(sv_player, ED_movetype) != MOVETYPE_NOCLIP)
		SV_WaterMove();
	else
		SV_AirMove();
	//johnfitz
}


/*
===================
SV_ReadClientMove
===================
*/
void SV_ReadClientMove(usercmd_t *move)
{
	int32_t         i;
	vec3_t  angle;
	int32_t         bits;

// read ping time
	host_client->ping_times[host_client->num_pings % NUM_PING_TIMES]
	        = sv.time - MSG_ReadFloat();
	host_client->num_pings++;

// read current angles
	for(i = 0 ; i < 3 ; i++)
		//johnfitz -- 16-bit angles for PROTOCOL_FITZQUAKE
		if(sv.protocol == PROTOCOL_NETQUAKE)
			angle[i] = MSG_ReadAngle(sv.protocolflags);
		else
			angle[i] = MSG_ReadAngle16(sv.protocolflags);
	//johnfitz

	VectorCopy(angle, ED_Vector(host_client->edict, ED_v_angle));

// read movement
	move->forwardmove = MSG_ReadShort();
	move->sidemove = MSG_ReadShort();
	move->upmove = MSG_ReadShort();

// read buttons
	bits = MSG_ReadByte();
	ED_Float(host_client->edict, ED_button0) = bits & 1;
	ED_Float(host_client->edict, ED_button2) = (bits & 2) >> 1;

	i = MSG_ReadByte();
	if(i)
		ED_Float(host_client->edict, ED_impulse) = i;
}

/*
===================
SV_ReadClientMessage

Returns false if the client should be killed
===================
*/
bool SV_ReadClientMessage(void)
{
	int32_t         ret;
	int32_t         ccmd;
	const char      *s;

	do
	{
nextmsg:
		ret = NET_GetMessage(host_client->netconnection);
		if(ret == -1)
		{
			Sys_Printf("SV_ReadClientMessage: NET_GetMessage failed\n");
			return false;
		}
		if(!ret)
			return true;

		MSG_BeginReading();

		while(1)
		{
			if(!host_client->active)
				return false;   // a command caused an error

			if(msg_badread)
			{
				Sys_Printf("SV_ReadClientMessage: badread\n");
				return false;
			}

			ccmd = MSG_ReadChar();

			switch(ccmd)
			{
			case -1:
				goto nextmsg;           // end of message

			default:
				Sys_Printf("SV_ReadClientMessage: unknown command char\n");
				return false;

			case clc_nop:
//				Sys_Printf ("clc_nop\n");
				break;

			case clc_stringcmd:
				s = MSG_ReadString();
				ret = 0;
				if(q_strncasecmp(s, "status", 6) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "god", 3) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "notarget", 8) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "fly", 3) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "name", 4) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "noclip", 6) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "setpos", 6) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "say", 3) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "say_team", 8) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "tell", 4) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "color", 5) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "kill", 4) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "pause", 5) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "spawn", 5) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "begin", 5) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "prespawn", 8) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "kick", 4) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "ping", 4) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "give", 4) == 0)
					ret = 1;
				else if(q_strncasecmp(s, "ban", 3) == 0)
					ret = 1;

				if(ret == 1)
					Cmd_ExecuteString(s, src_client);
				else
					Con_DPrintf("%s tried to %s\n", host_client->name, s);
				break;

			case clc_disconnect:
//				Sys_Printf ("SV_ReadClientMessage: client disconnected\n");
				return false;

			case clc_move:
				SV_ReadClientMove(&host_client->cmd);
				break;
			}
		}
	}
	while(ret == 1);

	return true;
}


/*
==================
SV_RunClients
==================
*/
void SV_RunClients(void)
{
	int32_t                         i;

	for(i = 0, host_client = svs.clients ; i < svs.maxclients ; i++, host_client++)
	{
		if(!host_client->active)
			continue;

		sv_player = host_client->edict;

		if(!SV_ReadClientMessage())
		{
			SV_DropClient(false);   // client misbehaved...
			continue;
		}

		if(!host_client->spawned)
		{
			// clear client movement until a new packet is received
			memset(&host_client->cmd, 0, sizeof(host_client->cmd));
			continue;
		}

// always pause in single player if in console or menus
		if(!sv.paused && (svs.maxclients > 1 || key_dest == key_game))
			SV_ClientThink();
	}
}