/*
  Copyright (C) 2010-2011  Charles Pence <charles@charlespence.net>
  Copyright (C) 1996-1997  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 3 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, see <http://www.gnu.org/licenses/>.
*/
#include "pch.h"
#include "quakedef.h"

edict_t    *sv_player;

static    vec3_t        forward, right, up;

vec3_t    wishdir;
float    wishspeed;

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

qboolean    onground;

usercmd_t    cmd;



/*
===============
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 * Cvar_VariableValue("sv_idealpitchscale");
}


/*
==================
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);

    friction = Cvar_VariableValue("sv_friction");
    if (trace.fraction == 1.0)
        friction *= Cvar_VariableValue("edgefriction");

// apply friction
    control = speed < Cvar_VariableValue("sv_stopspeed") ? Cvar_VariableValue("sv_stopspeed") : 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
==============
*/
void SV_Accelerate (void)
{
    int            i;
    float        addspeed, accelspeed, currentspeed;

    currentspeed = DotProduct (velocity, wishdir);
    addspeed = wishspeed - currentspeed;
    if (addspeed <= 0)
        return;
    accelspeed = Cvar_VariableValue("sv_accelerate") * 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 = Cvar_VariableValue("sv_accelerate") * 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 > Cvar_VariableValue("sv_maxspeed"))
    {
        VectorScale (wishvel, Cvar_VariableValue("sv_maxspeed") / wishspeed, wishvel);
        wishspeed = Cvar_VariableValue("sv_maxspeed");
    }
    wishspeed *= 0.7;

//
// water friction
//
    speed = Length (velocity);
    if (speed)
    {
        newspeed = speed - host_frametime * speed * Cvar_VariableValue("sv_friction");
        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 = Cvar_VariableValue("sv_accelerate") * 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 > Cvar_VariableValue("sv_maxspeed"))
    {
        VectorScale (wishvel, Cvar_VariableValue("sv_maxspeed") / wishspeed, wishvel);
        wishspeed = Cvar_VariableValue("sv_maxspeed");
    }

    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)
        {
            Con_DPrintf ("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)
            {
                Con_DPrintf ("SV_ReadClientMessage: badread\n");
                return false;
            }

            cmd = MSG_ReadChar ();

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

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

            case clc_nop:
                break;

            case clc_stringcmd:
                s = MSG_ReadString ();
                if (host_client->privileged)
                    ret = 2;
                else
                    ret = 0;
                if (strncasecmp(s, "status", 6) == 0)
                    ret = 1;
                else if (strncasecmp(s, "god", 3) == 0)
                    ret = 1;
                else if (strncasecmp(s, "notarget", 8) == 0)
                    ret = 1;
                else if (strncasecmp(s, "fly", 3) == 0)
                    ret = 1;
                else if (strncasecmp(s, "name", 4) == 0)
                    ret = 1;
                else if (strncasecmp(s, "noclip", 6) == 0)
                    ret = 1;
                else if (strncasecmp(s, "say", 3) == 0)
                    ret = 1;
                else if (strncasecmp(s, "say_team", 8) == 0)
                    ret = 1;
                else if (strncasecmp(s, "tell", 4) == 0)
                    ret = 1;
                else if (strncasecmp(s, "color", 5) == 0)
                    ret = 1;
                else if (strncasecmp(s, "kill", 4) == 0)
                    ret = 1;
                else if (strncasecmp(s, "pause", 5) == 0)
                    ret = 1;
                else if (strncasecmp(s, "spawn", 5) == 0)
                    ret = 1;
                else if (strncasecmp(s, "begin", 5) == 0)
                    ret = 1;
                else if (strncasecmp(s, "prespawn", 8) == 0)
                    ret = 1;
                else if (strncasecmp(s, "kick", 4) == 0)
                    ret = 1;
                else if (strncasecmp(s, "ping", 4) == 0)
                    ret = 1;
                else if (strncasecmp(s, "give", 4) == 0)
                    ret = 1;
                else if (strncasecmp(s, "ban", 3) == 0)
                    ret = 1;
                if (ret == 2)
                    Cbuf_InsertText (s);
                else if (ret == 1)
                    Cmd_ExecuteString (s, src_client);
                else
                    Con_DPrintf("%s tried to %s\n", host_client->name, s);
                break;

            case clc_disconnect:
                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;
        }

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

