#include "steerlib.qh"
#if defined(CSQC)
#elif defined(MENUQC)
#elif defined(SVQC)
    #include "pathlib/utility.qh"
#endif

/**
    Uniform pull towards a point
**/
#define steerlib_pull(ent,point) normalize(point - (ent).origin)
/*vector steerlib_pull(entity this, vector point)
{
    return normalize(point - this.origin);
}*/

/**
    Uniform push from a point
**/
#define steerlib_push(ent,point) normalize((ent).origin - point)
/*
vector steerlib_push(entity this, vector point)
{
    return normalize(this.origin - point);
}
*/
/**
    Pull toward a point, The further away, the stronger the pull.
**/
vector steerlib_arrive(entity this, vector point, float maximal_distance)
{
    float distance = bound(0.001, vlen(this.origin - point), maximal_distance);
    vector direction = normalize(point - this.origin);
    return  direction * (distance / maximal_distance);
}

/**
    Pull toward a point increasing the pull the closer we get
**/
vector steerlib_attract(entity this, vector point, float maximal_distance)
{
    float distance = bound(0.001, vlen(this.origin - point), maximal_distance);
    vector direction = normalize(point - this.origin);

    return  direction * (1 - (distance / maximal_distance));
}

vector steerlib_attract2(entity this, vector point, float min_influense, float max_distance, float max_influense)
{
    float distance = bound(0.00001, vlen(this.origin - point), max_distance);
    vector direction = normalize(point - this.origin);

    float influense = 1 - (distance / max_distance);
    influense = min_influense + (influense * (max_influense - min_influense));

    return direction * influense;
}

/*
vector steerlib_attract2(vector point, float maximal_distance,float min_influense,float max_influense,float distance)
{
    //float distance;
    vector current_direction;
    vector target_direction;
    float i_target,i_current;

    if(!distance)
        distance = vlen(this.origin - point);

    distance = bound(0.001,distance,maximal_distance);

    target_direction = normalize(point - this.origin);
    current_direction = normalize(this.velocity);

    i_target = bound(min_influense,(1-(distance / maximal_distance)),max_influense);
    i_current = 1 - i_target;

    // i_target = bound(min_influense,(1-(distance / maximal_distance)),max_influense);

    string s;
    s = ftos(i_target);
    bprint("IT: ",s,"\n");
    s = ftos(i_current);
    bprint("IC  : ",s,"\n");

    return  normalize((target_direction * i_target) + (current_direction * i_current));
}
*/
/**
    Move away from a point.
**/
vector steerlib_repel(entity this, vector point, float maximal_distance)
{
    float distance = bound(0.001, vlen(this.origin - point), maximal_distance);
    vector direction = normalize(this.origin - point);

    return  direction * (1 - (distance / maximal_distance));
}

/**
    Try to keep at ideal_distance away from point
**/
vector steerlib_standoff(entity this, vector point, float ideal_distance)
{
    vector direction;
    float distance = vlen(this.origin - point);

    if(distance < ideal_distance)
    {
        direction = normalize(this.origin - point);
        return direction * (distance / ideal_distance);
    }

    direction = normalize(point - this.origin);
    return direction * (ideal_distance / distance);

}

/**
    A random heading in a forward semicircle

    usage:
    this.target = steerlib_wander(256, 32, this.target)

    where range is the circle radius and threshold is how close we need to be to pick a new heading.
    Assumes v_forward is set by makevectors
**/
vector steerlib_wander(entity this, float range, float threshold, vector oldpoint)
{
    vector wander_point = v_forward - oldpoint;

    if (vdist(wander_point, >, threshold))
        return oldpoint;

    range = bound(0, range, 1);

    wander_point = this.origin + v_forward * 128;
    wander_point = wander_point + randomvec() * (range * 128) - randomvec() * (range * 128);

    return normalize(wander_point - this.origin);
}

/**
    Dodge a point NOTE: doesn't work well
**/
vector steerlib_dodge(entity this, vector point, vector dodge_dir, float min_distance)
{
    float distance = max(vlen(this.origin - point), min_distance);
    if (min_distance < distance)
        return '0 0 0';

    return dodge_dir * (min_distance / distance);
}

/**
    flocking by .flock_id
    Group will move towards the unified direction while keeping close to eachother.
**/
.float flock_id;
vector steerlib_flock(entity this, float _radius, float standoff, float separation_force, float flock_force)
{
    vector push = '0 0 0', pull = '0 0 0';
    int ccount = 0;

    entity flock_member = findradius(this.origin, _radius);
    while(flock_member)
    {
        if(flock_member != this)
        if(flock_member.flock_id == this.flock_id)
        {
            ++ccount;
            push = push + (steerlib_repel(this, flock_member.origin,standoff) * separation_force);
            pull = pull + (steerlib_arrive(this, flock_member.origin + flock_member.velocity, _radius) * flock_force);
        }
        flock_member = flock_member.chain;
    }
    return push + (pull* (1 / ccount));
}

/**
    flocking by .flock_id
    Group will move towards the unified direction while keeping close to eachother.
    xy only version (for ground movers).
**/
vector steerlib_flock2d(entity this, float _radius, float standoff, float separation_force, float flock_force)
{
    vector push = '0 0 0', pull = '0 0 0';
    int ccount = 0;

    entity flock_member = findradius(this.origin,_radius);
    while(flock_member)
    {
        if(flock_member != this)
        if(flock_member.flock_id == this.flock_id)
        {
            ++ccount;
            push = push + (steerlib_repel(this, flock_member.origin, standoff) * separation_force);
            pull = pull + (steerlib_arrive(this, flock_member.origin + flock_member.velocity, _radius) * flock_force);
        }
        flock_member = flock_member.chain;
    }

    push.z = 0;
    pull.z = 0;

    return push + (pull * (1 / ccount));
}

/**
    All members want to be in the center, and keep away from eachother.
    The further from the center the more they want to be there.

    This results in a aligned movement (?!) much like flocking.
**/
vector steerlib_swarm(entity this, float _radius, float standoff, float separation_force, float swarm_force)
{
    vector force = '0 0 0', center = '0 0 0';
    int ccount = 0;

    entity swarm_member = findradius(this.origin,_radius);
    while(swarm_member)
    {
        if(swarm_member.flock_id == this.flock_id)
        {
            ++ccount;
            center = center + swarm_member.origin;
            force = force + (steerlib_repel(this, swarm_member.origin,standoff) * separation_force);
        }
        swarm_member = swarm_member.chain;
    }

    center = center * (1 / ccount);
    force = force + (steerlib_arrive(this, center,_radius) * swarm_force);

    return force;
}

/**
    Steer towards the direction least obstructed.
    Run four tracelines in a forward funnel, bias each diretion negative if something is found there.
    You need to call makevectors() (or equivalent) before this function to set v_forward and v_right
**/
vector steerlib_traceavoid(entity this, float pitch, float length)
{
    vector v_left = v_right * -1;
    vector v_down = v_up * -1;

    vector vup_left = (v_forward + (v_left * pitch + v_up * pitch)) * length;
    traceline(this.origin, this.origin +  vup_left, MOVE_NOMONSTERS, this);
    float fup_left = trace_fraction;

    //te_lightning1(NULL,this.origin, trace_endpos);

    vector vup_right = (v_forward + (v_right * pitch + v_up * pitch)) * length;
    traceline(this.origin, this.origin + vup_right, MOVE_NOMONSTERS, this);
    float fup_right = trace_fraction;

    //te_lightning1(NULL,this.origin, trace_endpos);

    vector vdown_left = (v_forward + (v_left * pitch + v_down * pitch)) * length;
    traceline(this.origin, this.origin + vdown_left, MOVE_NOMONSTERS, this);
    float fdown_left = trace_fraction;

    //te_lightning1(NULL,this.origin, trace_endpos);

    vector vdown_right = (v_forward + (v_right * pitch + v_down * pitch)) * length;
    traceline(this.origin, this.origin + vdown_right, MOVE_NOMONSTERS, this);
    float fdown_right = trace_fraction;

    //te_lightning1(NULL,this.origin, trace_endpos);
    vector upwish    = v_up    * (fup_left   + fup_right);
    vector downwish  = v_down  * (fdown_left + fdown_right);
    vector leftwish  = v_left  * (fup_left   + fdown_left);
    vector rightwish = v_right * (fup_right  + fdown_right);

    return (upwish + leftwish + downwish + rightwish) * 0.25;

}

/**
    Steer towards the direction least obstructed.
    Run tracelines in a forward trident, bias each direction negative if something is found there.
    You need to call makevectors() (or equivalent) before this function to set v_forward and v_right
**/
vector steerlib_traceavoid_flat(entity this, float pitch, float length, vector vofs)
{
    vector v_left = v_right * -1;

    vector vt_front = v_forward * length;
    traceline(this.origin + vofs, this.origin + vofs + vt_front,MOVE_NOMONSTERS,this);
    float f_front = trace_fraction;

    vector vt_left = (v_forward + (v_left * pitch)) * length;
    traceline(this.origin + vofs, this.origin + vofs + vt_left,MOVE_NOMONSTERS,this);
    float f_left = trace_fraction;

    //te_lightning1(NULL,this.origin, trace_endpos);

    vector vt_right = (v_forward + (v_right * pitch)) * length;
    traceline(this.origin + vofs, this.origin + vofs + vt_right ,MOVE_NOMONSTERS,this);
    float f_right = trace_fraction;

    //te_lightning1(NULL,this.origin, trace_endpos);

    vector leftwish  = v_left    * f_left;
    vector rightwish = v_right   * f_right;
    vector frontwish = v_forward * f_front;

    return normalize(leftwish + rightwish + frontwish);
}

//#define BEAMSTEER_VISUAL
float beamsweep(entity this, vector from, vector dir, float length, float step, float step_up, float step_down)
{
    vector u = '0 0 1' * step_up;
    vector d = '0 0 1' * step_down;

    traceline(from + u, from - d,MOVE_NORMAL,this);
    if(trace_fraction == 1.0)
        return 0;

    if(!location_isok(trace_endpos, false, false))
        return 0;

    vector a = trace_endpos;
    for(int i = 0; i < length; i += step)
    {

        vector b = a + dir * step;
        tracebox(a + u,'-4 -4 -4','4 4 4', b + u,MOVE_NORMAL,this);
        if(trace_fraction != 1.0)
            return i / length;

        traceline(b + u, b - d,MOVE_NORMAL,this);
        if(trace_fraction == 1.0)
            return i / length;

        if(!location_isok(trace_endpos, false, false))
            return i / length;
#ifdef BEAMSTEER_VISUAL
        te_lightning1(NULL,a+u,b+u);
        te_lightning1(NULL,b+u,b-d);
#endif
        a = trace_endpos;
    }

    return 1;
}

vector steerlib_beamsteer(entity this, vector dir, float length, float step, float step_up, float step_down)
{
    dir.z *= 0.15;
    vector vr = vectoangles(dir);
    //vr.x *= -1;

    tracebox(this.origin + '0 0 1' * step_up, this.mins, this.maxs, ('0 0 1' * step_up) + this.origin +  (dir * length), MOVE_NOMONSTERS, this);
    if(trace_fraction == 1.0)
    {
        //te_lightning1(this,this.origin,this.origin + (dir * length));
        return dir;
    }

    makevectors(vr);
    float bm_forward = beamsweep(this, this.origin, v_forward, length, step, step_up, step_down);

    vr = normalize(v_forward + v_right * 0.125);
    vector vl = normalize(v_forward - v_right * 0.125);

    float bm_right = beamsweep(this, this.origin, vr, length, step, step_up, step_down);
    float bm_left  = beamsweep(this, this.origin, vl, length, step, step_up, step_down);

    float p = bm_left + bm_right;
    if(p == 2)
    {
        //te_lightning1(this,this.origin + '0 0 32',this.origin + '0 0 32' + vr * length);
        //te_lightning1(this.tur_head,this.origin + '0 0 32',this.origin + '0 0 32' + vl * length);

        return v_forward;
    }

    p = 2 - p;

    vr = normalize(v_forward + v_right * p);
    vl = normalize(v_forward - v_right * p);
    bm_right = beamsweep(this, this.origin, vr, length, step, step_up, step_down);
    bm_left  = beamsweep(this, this.origin, vl, length, step, step_up, step_down);


    if(bm_left + bm_right < 0.15)
    {
        vr = normalize((v_forward*-1) + v_right * 0.90);
        vl = normalize((v_forward*-1) - v_right * 0.90);

        bm_right = beamsweep(this, this.origin, vr, length, step, step_up, step_down);
        bm_left  = beamsweep(this, this.origin, vl, length, step, step_up, step_down);
    }

    //te_lightning1(this,this.origin + '0 0 32',this.origin + '0 0 32' + vr * length);
    //te_lightning1(this.tur_head,this.origin + '0 0 32',this.origin + '0 0 32' + vl * length);

    bm_forward *= bm_forward;
    bm_right   *= bm_right;
    bm_left    *= bm_left;

    vr = vr * bm_right;
    vl = vl * bm_left;

    return normalize(vr + vl);
}