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

#include "quakedef.h"

edict_t *sv_player;

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

static vec3_t forward, right, up;

vec3_t wishdir;
float wishspeed;

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

qboolean onground;

usercmd_t cmd;

cvar_t sv_idealpitchscale = { "sv_idealpitchscale", "0.8" };


/*
===============
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];
    int i, j;
    int step, dir, steps;

    if (!((int) sv_player->v.flags & FL_ONGROUND))
	return;

    angleval = sv_player->v.angles[YAW] * M_PI * 2 / 360;
    sinval = sin(angleval);
    cosval = cos(angleval);

    for (i = 0; i < MAX_FORWARD; i++) {
	top[0] = sv_player->v.origin[0] + cosval * (i + 3) * 12;
	top[1] = sv_player->v.origin[1] + sinval * (i + 3) * 12;
	top[2] = sv_player->v.origin[2] + sv_player->v.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) {
	sv_player->v.idealpitch = 0;
	return;
    }

    if (steps < 2)
	return;
    sv_player->v.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] + sv_player->v.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", false, true };
cvar_t sv_accelerate = { "sv_accelerate", "10" };
#if 0
void SV_Accelerate(vec3_t wishvel)
{
    int i;
    float addspeed, accelspeed;
    vec3_t pushvec;

    if (wishspeed == 0)
	return;

    VectorSubtract(wishvel, velocity, pushvec);
    addspeed = VectorNormalize(pushvec);

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

    for (i = 0; i < 3; i++)
	velocity[i] += accelspeed * pushvec[i];
}
#endif
void SV_Accelerate(void)
{
    int 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(vec3_t wishveloc)
{
    int 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(sv_player->v.punchangle);

    len -= 10 * host_frametime;
    if (len < 0)
	len = 0;
    VectorScale(sv_player->v.punchangle, len, sv_player->v.punchangle);
}

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

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

//
// user intentions
//
    AngleVectors(sv_player->v.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 = Length(wishvel);
    if (wishspeed > sv_maxspeed.value) {
	VectorScale(wishvel, sv_maxspeed.value / wishspeed, wishvel);
	wishspeed = sv_maxspeed.value;
    }
    wishspeed *= 0.7;

//
// water friction
//
    speed = Length(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 > sv_player->v.teleport_time || !sv_player->v.waterlevel) {
	sv_player->v.flags = (int) sv_player->v.flags & ~FL_WATERJUMP;
	sv_player->v.teleport_time = 0;
    }
    sv_player->v.velocity[0] = sv_player->v.movedir[0];
    sv_player->v.velocity[1] = sv_player->v.movedir[1];
}


/*
===================
SV_AirMove

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

    AngleVectors(sv_player->v.angles, forward, right, up);

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

// hack to not let you back into teleporter
    if (sv.time < sv_player->v.teleport_time && fmove < 0)
	fmove = 0;

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

    if ((int) sv_player->v.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 (sv_player->v.movetype == MOVETYPE_NOCLIP) {	// noclip
	VectorCopy(wishvel, velocity);
    } else if (onground) {
	SV_UserFriction();
	SV_Accelerate();
    } else {			// not on ground, so little effect on velocity
	SV_AirAccelerate(wishvel);
    }
}

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

the move fields specify an intended velocity in pix/sec
the angle fields specify an exact angular motion in degrees
===================
*/
void SV_ClientThink(void)
{
    vec3_t v_angle;

    if (sv_player->v.movetype == MOVETYPE_NONE)
	return;

    onground = (int) sv_player->v.flags & FL_ONGROUND;

    origin = sv_player->v.origin;
    velocity = sv_player->v.velocity;

    DropPunchAngle();

//
// if dead, behave differently
//
    if (sv_player->v.health <= 0)
	return;

//
// angles
// show 1/3 the pitch angle and all the roll angle
    cmd = host_client->cmd;
    angles = sv_player->v.angles;

    VectorAdd(sv_player->v.v_angle, sv_player->v.punchangle, v_angle);
    angles[ROLL] =
	V_CalcRoll(sv_player->v.angles, sv_player->v.velocity) * 4;
    if (!sv_player->v.fixangle) {
	angles[PITCH] = -v_angle[PITCH] / 3;
	angles[YAW] = v_angle[YAW];
    }

    if ((int) sv_player->v.flags & FL_WATERJUMP) {
	SV_WaterJump();
	return;
    }
//
// walk
//
    if ((sv_player->v.waterlevel >= 2)
	&& (sv_player->v.movetype != MOVETYPE_NOCLIP)) {
	SV_WaterMove();
	return;
    }

    SV_AirMove();
}


/*
===================
SV_ReadClientMove
===================
*/
void SV_ReadClientMove(usercmd_t * move)
{
    int i;
    vec3_t angle;
    int 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++)
	angle[i] = MSG_ReadAngle();

    VectorCopy(angle, host_client->edict->v.v_angle);

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

// read buttons
    bits = MSG_ReadByte();
    host_client->edict->v.button0 = bits & 1;
    host_client->edict->v.button2 = (bits & 2) >> 1;

    i = MSG_ReadByte();
    if (i)
	host_client->edict->v.impulse = i;
}

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

Returns false if the client should be killed
===================
*/
qboolean SV_ReadClientMessage(void)
{
    int ret;
    int cmd;
    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;
	    }

	    cmd = MSG_ReadChar();

	    switch (cmd) {
	    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();
		Cmd_ExecuteString(s, src_client);
		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)
{
    int 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;
	}
// allways pause in single player if in console or menus
	if (!sv.paused && (svs.maxclients > 1 || key_dest == key_game))
	    SV_ClientThink();
    }
}
