#include "CActorLights.hpp"
#include "Graphics/CModel.hpp"
#include "World/CGameArea.hpp"
#include "CStateManager.hpp"
#include "Collision/CGameCollision.hpp"
#include "Camera/CFirstPersonCamera.hpp"
#include "World/CGameLight.hpp"
#include "TCastTo.hpp"
#include "GameGlobalObjects.hpp"
#include "World/CExplosion.hpp"
#include "Graphics/CBooRenderer.hpp"

namespace urde
{

s32 CActorLights::sFrameSchedulerCount = 0;
CActorLights::CActorLights(u32 areaUpdateFramePeriod, const zeus::CVector3f& actorPosBias,
                           int maxDynamicLights, int maxAreaLights, bool ambientChannelOverflow,
                           bool layer2, bool disableWorldLights, float positionUpdateThreshold)
: x2a8_areaUpdateFramePeriod(areaUpdateFramePeriod), x2ac_actorPosBias(actorPosBias),
  x2b8_maxAreaLights(maxAreaLights), x2bc_maxDynamicLights(maxDynamicLights),
  x2cc_actorPositionDeltaUpdateThreshold(positionUpdateThreshold * positionUpdateThreshold)
{
    x298_24_dirty = true;
    x298_25_castShadows = true;

    x298_28_inArea = (!disableWorldLights && maxAreaLights > 0) ? true : false;
    x298_29_ambientChannelOverflow = ambientChannelOverflow;
    x298_30_layer2 = layer2;
    x298_31_disableWorldLights = disableWorldLights;
    x299_24_inBrightLight = true;

    sFrameSchedulerCount++;
    sFrameSchedulerCount &= 7;
}

void CActorLights::BuildConstantAmbientLighting()
{
    x299_26_ = true;
    x298_24_dirty = true;
    x29c_shadowLightArrIdx = -1;
    x2a0_shadowLightIdx = -1;
}

void CActorLights::BuildConstantAmbientLighting(const zeus::CColor& color)
{
    x299_26_ = false;
    x288_ambientColor = color;
    x294_aid = kInvalidAreaId;
    x298_24_dirty = true;
    x298_26_hasAreaLights = true;
    x29c_shadowLightArrIdx = -1;
    x2a0_shadowLightIdx = -1;
}

void CActorLights::BuildFakeLightList(const std::vector<CLight>& lights, const zeus::CColor& color)
{
    BuildConstantAmbientLighting(color);
    x0_areaLights.clear();
    x144_dynamicLights = lights;
}

void CActorLights::BuildFaceLightList(const CStateManager& mgr, const CGameArea& area, const zeus::CAABox& aabb)
{
    zeus::CTransform fpTransform = mgr.GetCameraManager()->GetFirstPersonCamera()->GetTransform();
    x288_ambientColor = zeus::CColor::skBlack;
    x144_dynamicLights.clear();
    zeus::CColor accumColor = zeus::CColor::skBlack;
    for (CEntity* light : mgr.GetLightObjectList())
    {
        if (!light || !light->GetActive())
            continue;
        CGameLight* castLight = static_cast<CGameLight*>(light);
        if (TCastToConstPtr<CExplosion> explosion = mgr.GetObjectById(castLight->GetParentId()))
        {
            CLight originalLight = castLight->GetLight();
            CLight explosionLight = originalLight;
            explosionLight.SetAttenuation(explosionLight.GetAttenuationConstant() * g_tweakGui->GetExplosionLightFalloffMultConstant(),
                                          explosionLight.GetAttenuationLinear() * g_tweakGui->GetExplosionLightFalloffMultLinear(),
                                          explosionLight.GetAttenuationQuadratic() * g_tweakGui->GetExplosionLightFalloffMultQuadratic());
            zeus::CVector3f camToExplo = explosion->GetTranslation() - fpTransform.origin;
            if (fpTransform.transposeRotate(camToExplo).dot(zeus::CVector3f::skForward) >= 0.f)
            {
                camToExplo.y = -camToExplo.y + ITweakGui::FaceReflectionDistanceDebugValueToActualValue(
                                               g_tweakGui->GetFaceReflectionDistance());
                camToExplo.z = -camToExplo.z + ITweakGui::FaceReflectionHeightDebugValueToActualValue(
                                               g_tweakGui->GetFaceReflectionHeight());
                explosionLight.SetPosition(fpTransform * camToExplo);
                zeus::CSphere sphere(originalLight.GetPosition(), originalLight.GetRadius());
                if (aabb.intersects(sphere))
                {
                    accumColor += explosionLight.GetNormalIndependentLightingAtPoint(fpTransform.origin);
                    if (originalLight.GetIntensity() > FLT_EPSILON && originalLight.GetRadius() > FLT_EPSILON)
                        x144_dynamicLights.push_back(explosionLight);
                }
            }
        }
    }

    float greyscale = accumColor.rgbDot(zeus::CColor(0.3f, 0.6f, 0.1f));
    if (greyscale < 0.012f)
        x144_dynamicLights.clear();

    if (greyscale > 0.03f)
    {
        float attMul = 1.f / (0.03f / greyscale);
        for (CLight& light : x144_dynamicLights)
            light.SetAttenuation(light.GetAttenuationConstant() * attMul,
                                 light.GetAttenuationLinear() * attMul,
                                 light.GetAttenuationQuadratic() * attMul);
    }
}

struct SLightValue
{
    u32 x0_areaLightIdx;
    zeus::CColor x4_color;
    float x10_colorMag;
    float x14_accumulatedMag = 0.f;
    EPVSVisSetState x18_visiblity;
};

void CActorLights::MergeOverflowLight(CLight& out, zeus::CColor& color, const CLight& in, float colorMag)
{
    color += in.GetColor() * colorMag;
    out.SetAngleAttenuation(in.GetAngleAttenuationConstant() * colorMag + out.GetAngleAttenuationConstant(),
                            in.GetAngleAttenuationLinear() * colorMag + out.GetAngleAttenuationLinear(),
                            in.GetAngleAttenuationQuadratic() * colorMag + out.GetAngleAttenuationQuadratic());
    out.SetAttenuation(in.GetAttenuationConstant() * colorMag + out.GetAttenuationConstant(),
                       in.GetAttenuationLinear() * colorMag + out.GetAttenuationLinear(),
                       in.GetAttenuationQuadratic() * colorMag + out.GetAttenuationQuadratic());
    out.SetPosition(in.GetPosition() * colorMag + out.GetPosition());
    out.SetDirection(in.GetDirection() * colorMag + out.GetDirection());
}

void CActorLights::AddOverflowToLights(const CLight& light, const zeus::CColor& color, float mag)
{
    if (mag < 0.001f || x2b8_maxAreaLights < 1)
        return;

    mag = 1.f / mag;
    zeus::CColor useColor = color * mag;
    useColor.a = 1.f;
    x0_areaLights.push_back(CLight::BuildCustom(light.GetPosition() * mag, light.GetDirection() * mag, useColor,
                                                light.GetAttenuationConstant() * mag,
                                                light.GetAttenuationLinear() * mag,
                                                light.GetAttenuationQuadratic() * mag,
                                                light.GetAngleAttenuationConstant() * mag,
                                                light.GetAngleAttenuationLinear() * mag,
                                                light.GetAngleAttenuationQuadratic() * mag));
}

void CActorLights::MoveAmbienceToLights(const zeus::CColor& color)
{
    if (x298_29_ambientChannelOverflow)
    {
        x288_ambientColor += color * 0.333333f;
        x288_ambientColor.a = 1.f;
        return;
    }

    zeus::CColor useColor = x0_areaLights[0].GetColor() + color;
    float maxComponent = std::max(useColor.r, std::max(useColor.g, useColor.b));
    if (maxComponent > FLT_EPSILON)
        useColor *= (1.f / maxComponent);
    useColor.a = 1.f;
    x0_areaLights[0].SetColor(useColor);
}

void CActorLights::MultiplyLightingLevels(float level)
{
    x288_ambientColor *= level;
    for (CLight& light : x0_areaLights)
    {
        zeus::CColor color = light.GetColor();
        color *= level;
        color.a = 1.f;
        light.SetColor(color);
    }
}

void CActorLights::UpdateBrightLight()
{
    if (x2dc_brightLightLag > 0 && x299_24_inBrightLight)
        --x2dc_brightLightLag;
    else if (x2dc_brightLightLag < 15 && !x299_24_inBrightLight)
        ++x2dc_brightLightLag;
    x299_25_useBrightLightLag = true;
}

bool CActorLights::BuildAreaLightList(const CStateManager& mgr, const CGameArea& area, const zeus::CAABox& aabb)
{
    const std::vector<CWorldLight>& lightList = x298_30_layer2 ? area.GetPostConstructed()->x80_lightsB :
                                                                 area.GetPostConstructed()->x60_lightsA;
    const std::vector<CLight>& gfxLightList = x298_30_layer2 ? area.GetPostConstructed()->x90_gfxLightsB :
                                                               area.GetPostConstructed()->x70_gfxLightsA;
    float worldLightingLevel = area.GetPostConstructed()->x1128_worldLightingLevel;
    x298_26_hasAreaLights = lightList.size() != 0;
    if (!x298_26_hasAreaLights || !x298_28_inArea)
    {
        /* World lights disabled */
        if (x298_31_disableWorldLights)
            x2d4_worldLightingLevel = worldLightingLevel;
        x29c_shadowLightArrIdx = -1;
        return true;
    }

    zeus::CVector3f vec;
    if (!x298_24_dirty && x294_aid == area.GetAreaId())
    {
        /* Early return if not ready for update */
        if (mgr.GetInputFrameIdx() - x2a4_lastUpdateFrame < x2a8_areaUpdateFramePeriod)
            return false;
        vec = aabb.center() + x2ac_actorPosBias;
        if (x2d4_worldLightingLevel == worldLightingLevel)
            if ((x2c0_lastActorPos - vec).magSquared() < x2cc_actorPositionDeltaUpdateThreshold)
                return false;
        x2c0_lastActorPos = vec;
    }
    else
    {
        if (x294_aid != area.GetAreaId())
            x2d8_brightLightIdx = -1;
        x2a4_lastUpdateFrame = sFrameSchedulerCount + mgr.GetInputFrameIdx();
        vec = aabb.center() + x2ac_actorPosBias;
        x2c0_lastActorPos = vec;
    }

    /* Reset lighting state */
    x2d4_worldLightingLevel = worldLightingLevel;
    x298_24_dirty = false;
    x294_aid = area.GetAreaId();
    x29c_shadowLightArrIdx = -1;
    x288_ambientColor = zeus::CColor::skClear;

    /* Find candidate lights via PVS */
    bool use2ndLayer;
    if (x298_30_layer2)
    {
        if (const CPVSAreaSet* pvs = area.GetAreaVisSet())
            use2ndLayer = pvs->Has2ndLayerLights();
        else
            use2ndLayer = true;
    }
    else
    {
        use2ndLayer = false;
    }

    CPVSVisSet sets[3];
    sets[0].Reset(EPVSVisSetState::OutOfBounds);
    sets[1].Reset(EPVSVisSetState::OutOfBounds);
    sets[2].Reset(EPVSVisSetState::OutOfBounds);

    if (const CPVSAreaSet* pvs = area.GetAreaVisSet())
    {
        zeus::CVector3f localVec = area.GetInverseTransform() * vec;
        sets[0].SetTestPoint(pvs->GetVisOctree(), localVec);
        localVec = area.GetInverseTransform() * aabb.max;
        sets[1].SetTestPoint(pvs->GetVisOctree(), localVec);
        localVec = area.GetInverseTransform() * aabb.min;
        sets[2].SetTestPoint(pvs->GetVisOctree(), localVec);
    }

    std::vector<SLightValue> valList;
    valList.reserve(lightList.size());

    auto lightIt = lightList.begin();
    int lightIdx = 0;
    for (const CLight& light : gfxLightList)
    {
        if (light.GetType() == ELightType::LocalAmbient)
        {
            /* Take ambient here */
            x288_ambientColor = light.GetNormalIndependentLightingAtPoint(vec);
        }
        else
        {
            EPVSVisSetState visible = EPVSVisSetState::OutOfBounds;
            if (area.GetAreaVisSet())
            {
                if (lightIt->DoesCastShadows())
                {
                    u32 pvsIdx;
                    if (use2ndLayer)
                        pvsIdx = area.Get2ndPVSLightFeature(lightIdx);
                    else
                        pvsIdx = area.Get1stPVSLightFeature(lightIdx);
                    visible = sets[0].GetVisible(pvsIdx);
                    if (visible != EPVSVisSetState::OutOfBounds)
                        visible = std::max(visible, sets[1].GetVisible(pvsIdx));
                    if (visible != EPVSVisSetState::OutOfBounds)
                        visible = std::max(visible, sets[2].GetVisible(pvsIdx));
                }
            }
            if (visible != EPVSVisSetState::EndOfTree)
            {
                zeus::CSphere sphere(light.GetPosition(), light.GetRadius() * 2.f);
                if (aabb.intersects(sphere))
                {
                    /* Light passes as candidate */
                    valList.emplace_back();
                    SLightValue& value = valList.back();
                    value.x0_areaLightIdx = lightIdx;
                    value.x4_color = light.GetNormalIndependentLightingAtPoint(vec);
                    value.x4_color.a = 0.f;
                    value.x10_colorMag = value.x4_color.magnitude();
                    value.x18_visiblity = visible;
                }
            }
        }
        ++lightIt;
        ++lightIdx;
    }

    /* Sort lights most intense to least intense */
    std::sort(valList.begin(), valList.end(),
    [](const SLightValue& a, const SLightValue& b)
    {
        return a.x10_colorMag >= b.x10_colorMag;
    });

    if (x298_27_findShadowLight)
    {
        /* Accumulate magnitudes up to most intense for shadow dynamic range check */
        x288_ambientColor.a = 0.f;
        float mag = x288_ambientColor.magnitude();
        for (auto it = valList.rbegin() ; it != valList.rend() ; ++it)
        {
            mag += it->x10_colorMag;
            it->x14_accumulatedMag = mag;
        }
    }

    /* Ambient color for overflow area lights */
    zeus::CColor overflowAmbColor;

    /* Averaged light for overflow area lights */
    CLight overflowLight = CLight::BuildCustom(zeus::CVector3f::skZero, zeus::CVector3f::skZero, zeus::CColor::skBlack,
                                               0.f, 0.f, 0.f, 0.f, 0.f, 0.f);
    zeus::CColor overflowLightColor;
    float overflowMag = 0.f;

    /* Max significant lights */
    int maxAreaLights = !x298_29_ambientChannelOverflow ? x2b8_maxAreaLights - 1 : x2b8_maxAreaLights;
    x0_areaLights.clear();

    /* Filter for performing final light visibility test */
    CMaterialFilter filter =
    CMaterialFilter::MakeIncludeExclude(CMaterialList(EMaterialTypes::Solid),
                                        CMaterialList(EMaterialTypes::Projectile, EMaterialTypes::ProjectilePassthrough,
                                                      EMaterialTypes::SeeThrough));
    u32 mostSigLightIdx = 0;

    /* Narrowphase test candidates starting with most intense */
    for (int i=0 ; i<valList.size() ; ++i)
    {
        const SLightValue& value = valList[i];
        const CLight& light = gfxLightList[value.x0_areaLightIdx];
        if (x0_areaLights.size() < maxAreaLights)
        {
            /* Significant light */
            bool actorToLightContact = true;
            bool castShadows = lightList[value.x0_areaLightIdx].DoesCastShadows() && x298_25_castShadows;
            bool outOfBounds = area.GetAreaVisSet() && value.x18_visiblity == EPVSVisSetState::OutOfBounds;
            if (castShadows)
            {
                /* Process shadow cast */
                zeus::CVector3f delta = light.GetPosition() - vec;
                float deltaMag = delta.magnitude();
                bool useShadow = false;
                if (x298_27_findShadowLight && x29c_shadowLightArrIdx == -1 && light.GetType() != ELightType::LocalAmbient &&
                    deltaMag > 2.f && !aabb.pointInside(light.GetPosition()))
                {
                    /* Perform shadow dynamic range check */
                    if (!x0_areaLights.size() ||
                        (x0_areaLights.size() == 1 && value.x10_colorMag / valList[mostSigLightIdx].x10_colorMag > 0.5f))
                    {
                        useShadow = value.x10_colorMag / value.x14_accumulatedMag >
                            x2d0_shadowDynamicRangeThreshold / (1.f + x2d0_shadowDynamicRangeThreshold);
                    }
                }
                if (useShadow)
                {
                    /* Note shadow light */
                    x29c_shadowLightArrIdx = x0_areaLights.size();
                    x2a0_shadowLightIdx = value.x0_areaLightIdx;
                }
                else if (!outOfBounds)
                {
                    /* Note brightest light contact */
                    delta = delta * 1.f / deltaMag;
                    actorToLightContact = CGameCollision::RayStaticIntersectionArea(area, vec, delta, deltaMag, filter);
                    if (i == 0)
                    {
                        x299_24_inBrightLight = actorToLightContact;
                        if (x2d8_brightLightIdx != value.x0_areaLightIdx)
                        {
                            x2dc_brightLightLag = actorToLightContact ? 0 : 15;
                            x2d8_brightLightIdx = value.x0_areaLightIdx;
                        }
                        x299_25_useBrightLightLag = false;
                        actorToLightContact = true;
                    }
                }
            }
            if (actorToLightContact)
            {
                /* Add to final list */
                if (x0_areaLights.size() == 0)
                    mostSigLightIdx = i;
                x0_areaLights.push_back(light);
            }
        }
        else
        {
            /* Overflow light */
            if (!x298_29_ambientChannelOverflow && value.x10_colorMag > 0.001f)
            {
                /* Average parameters into final light */
                MergeOverflowLight(overflowLight, overflowLightColor, light, value.x10_colorMag);
                overflowMag += value.x10_colorMag;
            }
            else
            {
                /* Average color into ambient channel */
                overflowAmbColor += value.x4_color;
            }
        }
    }

    /* Finalize overflow lights */
    if (!x298_29_ambientChannelOverflow)
        AddOverflowToLights(overflowLight, overflowLightColor, overflowMag);
    else
        MoveAmbienceToLights(overflowAmbColor);

    /* Clamp ambient color */
    if (x288_ambientColor.r > 1.f)
        x288_ambientColor.r = 1.f;
    if (x288_ambientColor.g > 1.f)
        x288_ambientColor.g = 1.f;
    if (x288_ambientColor.b > 1.f)
        x288_ambientColor.b = 1.f;
    x288_ambientColor.a = 1.f;

    /* Multiply down lighting with world fader level */
    if (worldLightingLevel < 1.f)
        MultiplyLightingLevels(worldLightingLevel);

    return true;
}

void CActorLights::BuildDynamicLightList(const CStateManager& mgr, const zeus::CAABox& aabb)
{
    UpdateBrightLight();
    x299_26_ = false;
    x144_dynamicLights.clear();

    if (!x29a_findNearestDynamicLights)
    {
        for (const CLight& light : mgr.GetDynamicLightList())
        {
            zeus::CSphere sphere(light.GetPosition(), light.GetRadius());
            if (aabb.intersects(sphere))
                x144_dynamicLights.push_back(light);
            if (x144_dynamicLights.size() >= x2bc_maxDynamicLights)
                break;
        }
    }
    else
    {
        const CLight* addedLights[8] = {};
        for (int i=0 ; i<x2bc_maxDynamicLights && i<8 ; ++i)
        {
            float minRad = FLT_MAX;
            for (const CLight& light : mgr.GetDynamicLightList())
            {
                zeus::CSphere sphere(light.GetPosition(), light.GetRadius());
                float intRadius = aabb.intersectionRadius(sphere);
                if (intRadius >= 0.f && intRadius < minRad)
                {
                    bool alreadyIn = false;
                    for (int j=0 ; j<i ; ++j)
                    {
                        if (&light == addedLights[j])
                        {
                            alreadyIn = true;
                            break;
                        }
                    }
                    if (alreadyIn)
                        continue;
                    addedLights[i] = &light;
                    minRad = intRadius;
                }
            }
            if (addedLights[i])
                x144_dynamicLights.push_back(*addedLights[i]);
            if (x144_dynamicLights.size() >= x2bc_maxDynamicLights)
                break;
        }
    }
}

std::vector<CLight> CActorLights::BuildLightVector() const
{
    std::vector<CLight> lights;
    lights.push_back(CLight::BuildLocalAmbient(zeus::CVector3f::skZero, x288_ambientColor));

    if (x0_areaLights.size())
    {
        if (x2dc_brightLightLag && x299_25_useBrightLightLag)
        {
            CLight overrideLight = x0_areaLights[0];
            overrideLight.SetColor(overrideLight.GetColor() * (1.f - x2dc_brightLightLag / 15.f));
            lights.push_back(overrideLight);
        }
        else
            lights.push_back(x0_areaLights[0]);

        for (auto it = x0_areaLights.begin() + 1 ; it != x0_areaLights.end() ; ++it)
        {
            lights.push_back(*it);
        }

        if (x29c_shadowLightArrIdx > 0)
        {
            /* Ensure shadow light comes first for shader extension */
            std::swap(lights[0], lights[x29c_shadowLightArrIdx]);
        }
    }

    for (const CLight& light : x144_dynamicLights)
        lights.push_back(light);

    return lights;
}

void CActorLights::ActivateLights(CBooModel& model) const
{
    std::vector<CLight> lights;

    if (x298_28_inArea)
    {
        if (!x298_26_hasAreaLights || !x299_26_)
        {
            g_Renderer->SetAmbientColor(zeus::CColor::skWhite);
            model.ActivateLights(lights);
            return;
        }
    }

    lights = BuildLightVector();
    model.ActivateLights(lights);

    if (x298_31_disableWorldLights)
    {
        zeus::CColor color(x2d4_worldLightingLevel);
        g_Renderer->SetWorldLightMultiplyColor(color);
    }
}

void CActorLights::DisableAreaLights()
{
    x2b8_maxAreaLights = 0;
    x298_26_hasAreaLights = false;
    x298_28_inArea = false;
}

const CLight& CActorLights::GetLight(u32 idx) const
{
    if (x298_28_inArea)
    {
        if (idx < x0_areaLights.size())
            return x0_areaLights[idx];
        return x144_dynamicLights[idx - x0_areaLights.size()];
    }
    return x144_dynamicLights[idx];
}

u32 CActorLights::GetActiveLightCount() const
{
    if (x298_28_inArea)
        return x0_areaLights.size() + x144_dynamicLights.size();
    return x144_dynamicLights.size();
}

}