/*
===========================================================================
Copyright (C) 2023 the OpenMoHAA team

This file is part of OpenMoHAA source code.

OpenMoHAA source code 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.

OpenMoHAA source code 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 OpenMoHAA source code; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/

// cg_ents.c -- present snapshot entities, happens every single frame

#include "cg_local.h"
#include "cg_radar.h"

/*
==========================================================================

FUNCTIONS CALLED EACH FRAME

==========================================================================
*/

/*
======================
CG_SetEntitySoundPosition
======================
*/
void CG_SetEntitySoundPosition(centity_t *cent)
{
    vec3_t origin;

    if (cent->currentState.solid == SOLID_BMODEL) {
        float *v;
        vec3_t vel;

        v = cgs.inlineModelMidpoints[cent->currentState.modelindex];
        VectorAdd(cent->lerpOrigin, v, origin);

        vel[0] = 0.0;
        vel[1] = 0.0;
        vel[2] = 0.0;

        cgi.S_UpdateEntity(cent->currentState.number, origin, vel, qfalse);
    } else {
        if (cent && cg.snap && cent->currentState.parent == cg.snap->ps.clientNum) {
            vec3_t origin;
            vec3_t velocity;

            origin[0] = 0;
            origin[1] = 0;
            origin[2] = 0;

            velocity[0] = 0;
            velocity[1] = 0;
            velocity[2] = 0;

            cgi.S_UpdateEntity(cent->currentState.number, origin, velocity, qtrue);
        } else {
            CG_GetOrigin(cent, origin);
            cgi.S_UpdateEntity(cent->currentState.number, origin, cent->currentState.pos.trDelta, qfalse);
        }
    }
}

/*
==================
CG_EntityEffects

Add continuous entity effects, like local entity emission and lighting
==================
*/
void CG_EntityEffects(centity_t *cent)
{
    // initialize with the client colors
    cent->color[0] = cent->client_color[0];
    cent->color[1] = cent->client_color[1];
    cent->color[2] = cent->client_color[2];
    cent->color[3] = cent->client_color[3];

    if (cent->currentState.constantLight != 0xffffff) {
        int      style;
        unsigned cl;
        float    i, r, g, b;

        cl    = cent->currentState.constantLight;
        style = (cl & 255);
        r     = (float)style / 255.0f;
        g     = (float)((cl >> 8) & 255) / 255.0f;
        b     = (float)((cl >> 16) & 255) / 255.0f;
        i     = ((cl >> 24) & 255) * CONSTANTLIGHT_RADIUS_SCALE;
        if (cent->currentState.renderfx & RF_LIGHTSTYLE_DLIGHT) {
            float color[4];

            CG_LightStyleColor(style, cg.time, color, qfalse);
            r = color[0];
            g = color[1];
            b = color[2];
            i *= color[3];
        }
        if (i) {
            int flags;

            flags = 0;
            if (cent->currentState.renderfx & RF_LENSFLARE) {
                flags |= lensflare;
            } else if (cent->currentState.renderfx & RF_VIEWLENSFLARE) {
                flags |= viewlensflare;
            }
            if (cent->currentState.renderfx & RF_ADDITIVE_DLIGHT) {
                flags |= additive;
            }
            cgi.R_AddLightToScene(cent->lerpOrigin, i, r, g, b, flags);
        }
        if (r < cent->color[0]) {
            cent->color[0] = r;
        }
        if (g < cent->color[1]) {
            cent->color[1] = g;
        }
        if (b < cent->color[2]) {
            cent->color[2] = b;
        }
    }
}

/*
==================
CG_General
==================
*/
void CG_General(centity_t *cent)
{
    refEntity_t    ent;
    entityState_t *s1;
    int            i;
    vec3_t         vMins, vMaxs, vTmp;

    s1 = &cent->currentState;

    // add loop sound
    if (s1->loopSound) {
        cgi.S_AddLoopingSound(
            cent->lerpOrigin,
            vec3_origin,
            cgs.sound_precache[s1->loopSound],
            s1->loopSoundVolume,
            s1->loopSoundMinDist,
            s1->loopSoundMaxDist,
            s1->loopSoundPitch,
            s1->loopSoundFlags
        );
    }
    if (cent->tikiLoopSound) {
        cgi.S_AddLoopingSound(
            cent->lerpOrigin,
            vec3_origin,
            cent->tikiLoopSound,
            cent->tikiLoopSoundVolume,
            cent->tikiLoopSoundMinDist,
            cent->tikiLoopSoundMaxDist,
            cent->tikiLoopSoundPitch,
            cent->tikiLoopSoundFlags
        );
    }

    if (s1->renderfx & RF_SKYORIGIN) {
        AnglesToAxis(cent->lerpAngles, cg.sky_axis);
        VectorCopy(cent->lerpOrigin, cg.sky_origin);
    }

    // if set to invisible, skip
    if (!s1->modelindex) {
        return;
    }

    if (s1->renderfx & RF_DONTDRAW) {
        return;
    }

    memset(&ent, 0, sizeof(ent));

    // set frame

    ent.wasframe = s1->wasframe;

    VectorCopy(cent->lerpOrigin, ent.origin);
    VectorCopy(cent->lerpOrigin, ent.oldorigin);

    // set skin
    IntegerToBoundingBox(s1->solid, vMins, vMaxs);
    VectorMA(ent.origin, 0.5f, ent.lightingOrigin, ent.lightingOrigin);
    VectorSubtract(vMins, vMaxs, vTmp);
    ent.radius = VectorLength(vTmp) * 0.5;

    ent.skinNum = s1->skinNum;

    ent.hModel = cgs.model_draw[s1->modelindex];

    // set surfaces
    memcpy(ent.surfaces, s1->surfaces, MAX_MODEL_SURFACES);

    // Modulation based off the color
    for (i = 0; i < 3; i++) {
        ent.shaderRGBA[i] = cent->color[i] * 255;
    }

    // take the alpha from the entity if less than 1, else grab it from the client commands version
    if (s1->alpha < 1) {
        ent.shaderRGBA[3] = s1->alpha * 255;
    } else {
        ent.shaderRGBA[3] = cent->color[3] * 255;
    }

    // convert angles to axis
    AnglesToAxis(cent->lerpAngles, ent.axis);

    // Interpolated state variables
    if (cent->interpolate) {
        ent.scale = s1->scale + cg.frameInterpolation * (cent->nextState.scale - cent->currentState.scale);
    } else {
        ent.scale = s1->scale;
    }
    // set the entity number
    ent.entityNumber = s1->number;

    // copy shader specific data
    ent.shader_data[0] = s1->tag_num;
    ent.shader_data[1] = s1->skinNum;
    ent.renderfx |= s1->renderfx;

    ent.tiki            = cgi.R_Model_GetHandle(cgs.model_draw[s1->modelindex]);
    ent.frameInfo[0]    = s1->frameInfo[0];
    ent.actionWeight    = 1.0;

    // add to refresh list
    cgi.R_AddRefEntityToScene(&ent, ENTITYNUM_NONE);

    if (ent.tiki) {
        // update any emitter's...
        CG_UpdateEntityEmitters(s1->number, &ent, cent);
    }
}

/*
==================
CG_Speaker

Speaker entities can automatically play sounds
==================
*/
void CG_Speaker(centity_t *cent)
{
    if (!cent->currentState.clientNum) // FIXME: use something other than clientNum...
    {
        return; // not auto triggering
    }

    if (cg.time < cent->miscTime) {
        return;
    }

    // FIXME
    //cgi.S_StartSound (NULL, cent->currentState.number, CHAN_ITEM, cgs.sound_precache[cent->currentState.eventParm] );

    //	ent->s.frame = ent->wait * 10;
    //	ent->s.clientNum = ent->random * 10;
    cent->miscTime = cg.time + cent->currentState.wasframe * 100 + cent->currentState.clientNum * 100 * crandom();
}

/*
===============
CG_Mover
===============
*/
void CG_Mover(centity_t *cent)
{
    refEntity_t    ent;
    entityState_t *s1;

    s1 = &cent->currentState;

    // create the render entity
    memset(&ent, 0, sizeof(ent));
    VectorCopy(cent->lerpOrigin, ent.origin);
    VectorCopy(cent->lerpOrigin, ent.oldorigin);
    AnglesToAxis(cent->lerpAngles, ent.axis);

    ent.renderfx &= ~RF_SHADOW;

    // flicker between two skins (FIXME?)
    ent.skinNum = (cg.time >> 6) & 1;

    // get the model, either as a bmodel or a modelindex
    if (s1->solid == SOLID_BMODEL) {
        ent.hModel = cgs.inlineDrawModel[s1->modelindex];
    } else {
        ent.hModel = cgs.model_draw[s1->modelindex];
    }

    // add to refresh list
    cgi.R_AddRefEntityToScene(&ent, ENTITYNUM_NONE);
}

/*
===============
CG_Beam
===============
*/
void CG_Beam(centity_t *cent)
{
    entityState_t *s1;
    vec3_t         vz = {0, 0, 0}, origin = {0, 0, 0};
    float          modulate[4];
    int            i;

    s1 = &cent->currentState;

    for (i = 0; i < 4; i++) {
        modulate[i] = cent->color[i];
    }

    if (s1->beam_entnum != ENTITYNUM_NONE) {
        refEntity_t *parent;
        parent = cgi.R_GetRenderEntity(s1->beam_entnum);

        if (!parent) {
            cgi.DPrintf("CG_Beam: Could not find parent entity\n");
            return;
        }

        VectorAdd(s1->origin, parent->origin, origin);
    } else {
        VectorCopy(s1->origin, origin);
    }

    CG_CreateBeam(
        origin,                                   // start
        vz,                                       // dir ( auto calculated by using origin2-origin )
        s1->number,                               // owner number
        cgs.model_draw[s1->modelindex],           //hModel
        s1->alpha,                                // alpha
        s1->scale,                                // scale
        s1->skinNum,                              // flags
        0,                                        // length ( auto calculated )
        PKT_TO_BEAM_PARM(s1->surfaces[0]) * 1000, // life
        qfalse,                                   // don't always create the beam, just update it
        s1->origin2,                              // endpoint
        s1->bone_angles[0][0],                    // min offset
        s1->bone_angles[0][1],                    // max offset
        PKT_TO_BEAM_PARM(s1->surfaces[3]),        // overlap
        s1->surfaces[4],                          // subdivisions
        PKT_TO_BEAM_PARM(s1->surfaces[5]) * 1000, // delay
        CG_ConfigString(CS_IMAGES + s1->tag_num), // index for shader configstring
        modulate,                                 // modulate color
        s1->surfaces[6],                          // num sphere beams
        PKT_TO_BEAM_PARM(s1->surfaces[7]),        // sphere radius
        PKT_TO_BEAM_PARM(s1->surfaces[8]),        // toggle delay
        PKT_TO_BEAM_PARM(s1->surfaces[9]),        // end alpha
        s1->renderfx,
        ""
    );
}

void CG_Decal(centity_t *cent)

{
    qhandle_t      shader;
    vec3_t         dir;
    entityState_t *s1;

    s1 = &cent->currentState;

    shader = cgi.R_RegisterShader(CG_ConfigString(CS_IMAGES + s1->tag_num));
    ByteToDir(s1->surfaces[0], dir);
    CG_ImpactMark(
        shader,
        s1->origin,
        dir,
        s1->angles[2],
        s1->scale,
        s1->scale,
        cent->color[0],
        cent->color[1],
        cent->color[2],
        cent->color[3],
        qtrue,
        qfalse,
        qtrue,
        qfalse,
        0.5f,
        0.5f
    );
}

/*
===============
CG_Portal
===============
*/
void CG_Portal(centity_t *cent) {}

/*
================
BG_EvaluateTrajectory
================
*/
void BG_EvaluateTrajectory(const trajectory_t *tr, int atTime, const vec3_t base, vec3_t result)
{
    float deltaTime;

    if (atTime > cg_smoothClientsTime->integer + tr->trTime) {
        atTime = cg_smoothClientsTime->integer + tr->trTime;
    }

    deltaTime = (float)(atTime - tr->trTime) / 1000.0;

    result[0] = tr->trDelta[0] * deltaTime + base[0];
    result[1] = tr->trDelta[1] * deltaTime + base[1];
    result[2] = tr->trDelta[2] * deltaTime + base[2];
}

/*
===============
CG_CalcEntityLerpPositions

===============
*/
void CG_CalcEntityLerpPositions(centity_t *cent)
{
    int   i;
    float f;

    f = cg.frameInterpolation;

    if (cent->currentState.eType == ET_PLAYER) {
        if (cent->currentState.number == cg.snap->ps.clientNum) {
            // if the player, take position from prediction
            VectorCopy(cg.predicted_player_state.origin, cent->lerpOrigin);
            for (i = 0; i < 3; i++) {
                cent->lerpAngles[i] = LerpAngle(cent->currentState.angles[i], cent->nextState.angles[i], f);
            }

            return;
        }
    }

    if (cent->currentState.eType != ET_PLAYER || !cg_smoothClients->integer) {
        float quat[4];
        float mat[3][3];

        if (!cent->interpolate) {
            VectorCopy(cent->currentState.angles, cent->lerpAngles);
            VectorCopy(cent->currentState.origin, cent->lerpOrigin);
            return;
        }

        for (i = 0; i < 3; i++) {
            cent->lerpOrigin[i] =
                cent->currentState.origin[i] + f * (cent->nextState.origin[i] - cent->currentState.origin[i]);
        }

        if (!memcmp(cent->currentState.angles, cent->nextState.angles, sizeof(vec3_t))) {
            VectorCopy(cent->currentState.angles, cent->lerpAngles);
        } else {
            // use spherical interpolation using quaternions so that bound objects
            // rotate properly without gimble lock.
            SlerpQuaternion(cent->currentState.quat, cent->nextState.quat, f, quat);
            QuatToMat(quat, mat);
            MatrixToEulerAngles(mat, cent->lerpAngles);
        }
    } else if (cent->interpolate) {
        float quat[4];
        float mat[3][3];

        // if the entity has a valid next state, interpolate a value between the frames
        // unless it is a mover with a known start and stop
        vec3_t current, next;

        // this will linearize a sine or parabolic curve, but it is important
        // to not extrapolate player positions if more recent data is available
        BG_EvaluateTrajectory(&cent->currentState.pos, cg.snap->serverTime, cent->currentState.origin, current);
        BG_EvaluateTrajectory(&cent->nextState.pos, cg.nextSnap->serverTime, cent->nextState.origin, next);

        cent->lerpOrigin[0] = current[0] + f * (next[0] - current[0]);
        cent->lerpOrigin[1] = current[1] + f * (next[1] - current[1]);
        cent->lerpOrigin[2] = current[2] + f * (next[2] - current[2]);

        if (!memcmp(cent->currentState.angles, cent->nextState.angles, sizeof(vec3_t))) {
            VectorCopy(cent->currentState.angles, cent->lerpAngles);
        } else {
            // use spherical interpolation using quaternions so that bound objects
            // rotate properly without gimble lock.
            SlerpQuaternion(cent->currentState.quat, cent->nextState.quat, f, quat);
            QuatToMat(quat, mat);
            MatrixToEulerAngles(mat, cent->lerpAngles);
        }
    } else {
        // just use the current frame and evaluate as best we can
        BG_EvaluateTrajectory(&cent->currentState.pos, cg.time, cent->currentState.origin, cent->lerpOrigin);
        VectorCopy(cent->currentState.angles, cent->lerpAngles);
    }
}

/*
===============
CG_AddCEntity

===============
*/
void CG_AddCEntity(centity_t *cent)
{
    // event-only entities will have been dealt with already
    if (cent->currentState.eType >= ET_EVENTS) {
        return;
    }

    // calculate the current origin
    CG_CalcEntityLerpPositions(cent);

    // add automatic effects
    CG_EntityEffects(cent);

    CG_SetEntitySoundPosition(cent);

    switch (cent->currentState.eType) {
    default:
        cgi.Error(ERR_DROP, "Bad entity type: %i\n", cent->currentState.eType);
        break;
        // intentional fallthrough
    case ET_MODELANIM_SKEL:
    case ET_MODELANIM:
        CG_Splash(cent);
        CG_ModelAnim(cent, qfalse);
        break;
    case ET_VEHICLE:
        CG_Vehicle(cent);
        CG_Splash(cent);
        CG_ModelAnim(cent, qtrue);
        break;
    case ET_PLAYER:
        CG_Player(cent);
		CG_Splash(cent);
		CG_ModelAnim(cent, qfalse);
        CG_UpdateRadarClient(cent);
        break;
    case ET_ITEM:
        CG_ModelAnim(cent, qfalse);
        break;
    case ET_GENERAL:
        CG_General(cent);
        break;
    case ET_MOVER:
        CG_Mover(cent);
        break;
    case ET_BEAM:
        CG_Beam(cent);
        break;
    case ET_MULTIBEAM: // skip
        break;
    case ET_PORTAL:
        CG_Portal(cent);
        break;
    case ET_RAIN:
        CG_Rain(cent);
        break;
    case ET_DECAL:
        CG_Decal(cent);
        break;
    case ET_EMITTER:
        CG_Emitter(cent);
        break;
    case ET_ROPE: // skip
        CG_Rope(cent);
        break;
    case ET_EXEC_COMMANDS:
        CG_ModelAnim(cent, qfalse);
        break;
    }
}

/*
===============
CG_AddPacketEntities

===============
*/
void CG_AddPacketEntities(void)
{
    int        num;
    centity_t *cent;
    int        child, parent;
    qboolean   processed[MAX_ENTITIES];
    int        i;

    // the auto-rotating items will all have the same axis
    cg.autoAngles[0] = 0;
    cg.autoAngles[1] = (cg.time & 2047) * 360 / 2048.0;
    cg.autoAngles[2] = 0;

    cg.autoAnglesSlow[0] = 0;
    cg.autoAnglesSlow[1] = (cg.time & 4095) * 360 / 4096.0f;
    cg.autoAnglesSlow[2] = 0;

    cg.autoAnglesFast[0] = 0;
    cg.autoAnglesFast[1] = (cg.time & 1023) * 360 / 1024.0f;
    cg.autoAnglesFast[2] = 0;

    AnglesToAxis(cg.autoAngles, cg.autoAxis);
    AnglesToAxis(cg.autoAnglesSlow, cg.autoAxisSlow);
    AnglesToAxis(cg.autoAnglesFast, cg.autoAxisFast);

    for (i = 0; i < MAX_ENTITIES; i++) {
        processed[i] = qtrue;
    }

    for (num = 0; num < cg.snap->numEntities; ++num) {
        processed[cg.snap->entities[num].number] = qfalse;
    }

    // add each entity sent over by the server
    for (num = 0; num < cg.snap->numEntities; num++) {
        child = cg.snap->entities[num].number;
        cent  = &cg_entities[child];
        // add the parent first
        // so attachments are consistent
        for (parent = cent->currentState.parent; parent != ENTITYNUM_NONE && !processed[parent];
             parent = cg_entities[parent].currentState.parent) {
            processed[parent] = qtrue;
            CG_AddCEntity(&cg_entities[parent]);
        }

        if (!processed[child]) {
            // now add the children if not processed
            processed[child] = qtrue;
            CG_AddCEntity(cent);
        }
    }

    // Add in the multibeams at the end
    for (num = 0; num < cg.snap->numEntities; num++) {
        cent = &cg_entities[cg.snap->entities[num].number];
        if (cent->currentState.eType == ET_MULTIBEAM) {
            CG_MultiBeam(cent);
        }
    }
}

void CG_GetOrigin(centity_t *cent, vec3_t origin)
{
    if (cent->currentState.parent == ENTITYNUM_NONE) {
        VectorCopy(cent->lerpOrigin, origin);
    } else {
        int i;
        orientation_t or ;
        refEntity_t *parent;

        parent = cgi.R_GetRenderEntity(cent->currentState.parent);

        if (!parent) {
            return;
        }

        cgi.R_Model_GetHandle(parent->hModel);
        or = cgi.TIKI_Orientation(parent, cent->currentState.tag_num);

        VectorCopy(parent->origin, origin);

        for (i = 0; i < 3; i++) {
            VectorMA(origin, or.origin[i], parent->axis[i], origin);
        }
    }
}