#include "Rendering/RenderSystem.h"
#include "Collision/Collision.h"
#include "Core/Frustum.h"

RenderSystem::RenderSystem(SystemParams params, const IRenderer* renderer, RenderFrame* renderFrame, Octree<EntityAABB>* frustumCullOctree)
    : System(params)
    , m_Renderer(renderer)
    , m_RenderFrame(renderFrame)
    , m_Octree(frustumCullOctree)
{
    EVENT_SUBSCRIBE_MEMBER(m_ESetCamera, &RenderSystem::OnSetCamera);
    EVENT_SUBSCRIBE_MEMBER(m_EResolutionChanged, &RenderSystem::OnResolutionChanged);
    EVENT_SUBSCRIBE_MEMBER(m_EInputCommand, &RenderSystem::OnInputCommand);
    EVENT_SUBSCRIBE_MEMBER(m_EPlayerSpawned, &RenderSystem::OnPlayerSpawned);

    m_Camera = new Camera((float)m_Renderer->GetViewportSize().Width / m_Renderer->GetViewportSize().Height, glm::radians(45.f), 0.01f, 5000.f);
}

RenderSystem::~RenderSystem()
{
    delete m_Camera;
}

bool RenderSystem::OnResolutionChanged(Events::ResolutionChanged& e)
{
    // Update camera aspect ration on resolution change
    m_Camera->SetAspectRatio((float)e.NewResolution.Width / e.NewResolution.Height);
    return true;
}

bool RenderSystem::OnSetCamera(Events::SetCamera& e)
{
    ComponentWrapper cTransform = e.CameraEntity["Transform"];
    ComponentWrapper cCamera = e.CameraEntity["Camera"];
    m_Camera->SetFOV(glm::radians((double)cCamera["FOV"]));
    m_Camera->SetNearClip((double)cCamera["NearClip"]);
    m_Camera->SetFarClip((double)cCamera["FarClip"]);
    m_Camera->SetPosition(cTransform["Position"]);
    m_Camera->SetOrientation(glm::quat((const glm::vec3&)cTransform["Orientation"]));
    m_CurrentCamera = e.CameraEntity;
    return true;
}


void RenderSystem::fillSprites(std::list<std::shared_ptr<RenderJob>>& jobs, World* world)
{
    auto sprites = world->GetComponents("Sprite");
    if (sprites == nullptr) {
        return;
    }

    for (auto& cSprite : *sprites) {
        bool visible = cSprite["Visible"];
        if (!visible) {
            continue;
        }
       
        EntityWrapper entity(world, cSprite.EntityID);
        if (!isEntityVisible(entity)) {
            continue;
        }

		glm::mat4 modelMatrix;

		// See a sprite is an SpriteIndicator
		bool isIndicator = false;
		if (world->HasComponent(entity.ID, "SpriteIndicator"))
		{
			auto indicator = entity["SpriteIndicator"];

			float minScale = (float)(double)indicator["MinScale"];
			bool hasTeam = indicator["VisibleForSingleTeamOnly"];
			isIndicator = true;
			glm::vec3 pos = TransformSystem::AbsolutePosition(entity);


			EntityWrapper entityTeam;
			if (hasTeam && (entity.HasComponent("Team") || entity.FirstParentWithComponent("Team").Valid()) && m_LocalPlayer.World != nullptr) {
				if (!entity.HasComponent("Team")) {
					entityTeam = entity.FirstParentWithComponent("Team");
				}
				else {
					entityTeam = entity;
				}

				ComponentWrapper& entityTeamComponent = entityTeam["Team"];
				ComponentWrapper& localComponent = m_LocalPlayer["Team"];
				int entityTeamInt = entityTeamComponent["Team"];
				int localComponentInt = localComponent["Team"];
				int SpectatorInt = localComponent["Team"].Enum("Spectator");
				if (entityTeamInt != localComponentInt && localComponentInt != SpectatorInt) {
					continue;
				}
			}

			// Code for check if sprite is inside or outside of screen
			//glm::vec4 projectedPos = m_Camera->ProjectionMatrix() * m_Camera->ViewMatrix() * glm::vec4(pos, 1.0f);
			//projectedPos /= projectedPos.w;
			//// Check if inside of outside of screen.
			//if (projectedPos.x < -1.0f || projectedPos.x > 1.0f || projectedPos.y < -1.0f || projectedPos.y > 1.0f) {
			//	// is outside of screen
			//} else {
			//	// is inside of screen
			//}


			glm::vec3 zAxis = glm::vec3(0.0f, 1.0f, 0.0f);
			glm::vec3 normal = pos - m_Camera->Position();

			//float distance = glm::length(normal);
			//if (distance < minDistance) {
			//	pos = pos - glm::normalize(normal) * (distance - minDistance);
			//} else if (distance > maxDistance) {
			//	pos = pos - glm::normalize(normal) * (distance - maxDistance);
			//}
			normal.y = 0;
			normal = glm::normalize(normal);
			glm::vec3 right = glm::cross(normal, zAxis);
			glm::vec3 up = glm::cross(right, normal);

			modelMatrix[0][0] = right.x;
			modelMatrix[0][1] = right.y;
			modelMatrix[0][2] = right.z;
			modelMatrix[0][3] = 0.0f;

			modelMatrix[1][0] = zAxis.x;
			modelMatrix[1][1] = zAxis.y;
			modelMatrix[1][2] = zAxis.z;
			modelMatrix[1][3] = 0.0f;

			modelMatrix[2][0] = normal.x;
			modelMatrix[2][1] = normal.y;
			modelMatrix[2][2] = normal.z;
			modelMatrix[2][3] = 0.0f;

			modelMatrix[3][0] = pos.x;
			modelMatrix[3][1] = pos.y;
			modelMatrix[3][2] = pos.z;
			modelMatrix[3][3] = 1.0f;

			glm::mat4 tranformationMatrix = modelMatrix * glm::scale(TransformSystem::AbsoluteScale(entity));
			glm::vec4 tmp = tranformationMatrix * glm::vec4(glm::vec3(0.5, 0.5, 0), 1.0f);
			glm::vec2 projectedTopRight = m_Camera->WorldToScreen(glm::vec3(tmp), m_Renderer->GetViewportSize());
			tmp = tranformationMatrix * glm::vec4(glm::vec3(-0.5, -0.5, 0), 1.0f);
			glm::vec2 projectedBottomLeft = m_Camera->WorldToScreen(glm::vec3(tmp), m_Renderer->GetViewportSize());

			float diag = glm::length(projectedBottomLeft - projectedTopRight);
			if (diag < minScale) {
				tranformationMatrix = tranformationMatrix * glm::scale(glm::vec3(minScale / diag, minScale / diag, minScale / diag));
			}
			modelMatrix = tranformationMatrix;
		}
		else {
			modelMatrix = TransformSystem::ModelMatrix(entity.ID, world);
		}


        std::string diffuseResource = cSprite["DiffuseTexture"];
        std::string glowResource = cSprite["GlowMap"];
        bool depthSorted = cSprite["DepthSort"];
        if (diffuseResource.empty() && glowResource.empty()) {
            continue;
        }

        float fillPercentage = 0.f;
        glm::vec4 fillColor = glm::vec4(0);
        if (world->HasComponent(entity.ID, "Fill")) {
            auto fillComponent = world->GetComponent(entity.ID, "Fill");
            fillPercentage = (float)(double)fillComponent["Percentage"];
            fillColor = (glm::vec4)fillComponent["Color"];
        }

        std::shared_ptr<SpriteJob> spriteJob = std::shared_ptr<SpriteJob>(new SpriteJob(cSprite, m_Camera, modelMatrix, world, fillColor, fillPercentage, depthSorted, isIndicator));
        
        jobs.push_back(spriteJob);
    }
}

bool RenderSystem::isEntityVisible(EntityWrapper& entity)
{
    // Only render children of a camera if that camera is currently active
    if (isChildOfACamera(entity) && !isChildOfCurrentCamera(entity)) {
        return false;
    }

    // Hide things parented to local player if they have the HiddenFromLocalPlayer component
    bool outOfBodyExperience = false; // ResourceManager::Load<ConfigFile>("Config.ini")->Get<bool>("Debug.OutOfBodyExperience", false);
    if (
        (entity.HasComponent("HiddenForLocalPlayer") || entity.FirstParentWithComponent("HiddenForLocalPlayer").Valid()) 
        && (entity == m_LocalPlayer || entity.IsChildOf(m_LocalPlayer)) 
        && !outOfBodyExperience
    ) {
        return false;
    }
    return true;
}

bool RenderSystem::isChildOfACamera(EntityWrapper entity)
{
    return entity.FirstParentWithComponent("Camera").Valid();
}
bool RenderSystem::isChildOfCurrentCamera(EntityWrapper entity)
{
    return entity == m_CurrentCamera || entity.IsChildOf(m_CurrentCamera);
}

void RenderSystem::fillModels(RenderScene::Queues &Jobs)
{
    Frustum frustum(m_Camera->ProjectionMatrix() * m_Camera->ViewMatrix());
    std::vector<EntityAABB> seenEntities;
    m_Octree->ObjectsInFrustum(frustum, seenEntities);

    for (auto& seenEntity : seenEntities) {
        EntityWrapper entity = seenEntity.Entity;
        ComponentWrapper cModel = entity["Model"];
        bool visible = cModel["Visible"];
        if (!visible) {
            continue;
        }
        std::string resource = cModel["Resource"];
        if (resource.empty()) {
            continue;
        }

        if (!isEntityVisible(entity)) {
            continue;
        }

        Model* model;
        try {
            model = ResourceManager::Load<::Model, true>(resource);
        } catch (const Resource::StillLoadingException&) {
            //continue;
            model = ResourceManager::Load<::Model>("Models/Core/UnitRaptor.mesh");
        } catch (const std::exception&) {
            try {
                model = ResourceManager::Load<::Model>("Models/Core/Error.mesh");
            } catch (const std::exception&) {
                continue;
            }
        }

        float fillPercentage = 0.f;
        glm::vec4 fillColor = glm::vec4(0);
        if(m_World->HasComponent(cModel.EntityID, "Fill")) {
            auto fillComponent = m_World->GetComponent(cModel.EntityID, "Fill");
            fillPercentage = (float)(double)fillComponent["Percentage"];
            fillColor = (glm::vec4)fillComponent["Color"];
        }

		bool isShielded = m_World->HasComponent(cModel.EntityID, "Shielded") || m_World->HasComponent(cModel.EntityID, "Player");

        glm::mat4 modelMatrix = TransformSystem::ModelMatrix(cModel.EntityID, m_World);
        //Loop through all materialgroups of a model
        for (auto matGroup : model->MaterialGroups()) {
            //If the model has an explosioneffect component, we will add an explosioneffectjob
            if (m_World->HasComponent(cModel.EntityID, "ExplosionEffect")) {
                auto explosionEffectComponent = m_World->GetComponent(cModel.EntityID, "ExplosionEffect");
                std::shared_ptr<ExplosionEffectJob> explosionEffectJob = std::shared_ptr<ExplosionEffectJob>(new ExplosionEffectJob(
                    explosionEffectComponent, 
                    model, 
                    m_Camera, 
                    modelMatrix, 
                    matGroup, 
                    cModel, 
                    m_World, 
                    fillColor, 
                    fillPercentage,
					isShielded,
					false
                ));
                if (m_World->HasComponent(cModel.EntityID, "Shield")){
                    explosionEffectJob->CalculateHash();
                    Jobs.ShieldObjects.push_back(explosionEffectJob);
                } else if (isShielded) {
                    if (explosionEffectJob->Color.a != 1.f || explosionEffectJob->EndColor.a != 1.f || explosionEffectJob->DiffuseColor.a != 1.f) {
                        cModel["Transparent"] = true;
                    }

                    if (cModel["Transparent"]) {
                        Jobs.TransparentObjects.push_back(explosionEffectJob);
                    } else {
					    explosionEffectJob->CalculateHash();
                        Jobs.OpaqueShieldedObjects.push_back(explosionEffectJob);
                    }
                } else {
                    if (explosionEffectJob->Color.a != 1.f || explosionEffectJob->EndColor.a != 1.f || explosionEffectJob->DiffuseColor.a != 1.f) {
                        cModel["Transparent"] = true;
                    }

                    if (cModel["Transparent"]) {
                        Jobs.TransparentObjects.push_back(explosionEffectJob);
                    } else {
                        explosionEffectJob->CalculateHash();
                        Jobs.OpaqueObjects.push_back(explosionEffectJob);
                    }
                }
            } else {
                std::shared_ptr<ModelJob> modelJob = std::shared_ptr<ModelJob>(new ModelJob(
                    model, 
                    m_Camera, 
                    modelMatrix, 
                    matGroup, 
                    cModel, 
                    m_World, 
                    fillColor, 
                    fillPercentage,
					isShielded,
					(bool)cModel["Shadow"]
                ));
                if (m_World->HasComponent(cModel.EntityID, "Shield")) {
                    modelJob->CalculateHash();
                    Jobs.ShieldObjects.push_back(modelJob);
                } else if (isShielded) {

                    if (modelJob->Color.a != 1.f || modelJob->DiffuseColor.a != 1.f) {
                        cModel["Transparent"] = true;
                    }

                    if (cModel["Transparent"]) {
                        Jobs.TransparentObjects.push_back(modelJob);
                    } else {
					    modelJob->CalculateHash();
                        Jobs.OpaqueShieldedObjects.push_back(modelJob);
                    }
                } else {
                    if (modelJob->Color.a != 1.f || modelJob->DiffuseColor.a != 1.f) {
                        cModel["Transparent"] = true;
                    }

                    if (cModel["Transparent"]) {
                        Jobs.TransparentObjects.push_back(modelJob);
                    } else {
                        modelJob->CalculateHash();
                        Jobs.OpaqueObjects.push_back(modelJob);
                    }
                }
            }
        }
    }
}

bool RenderSystem::OnPlayerSpawned(Events::PlayerSpawned& e)
{
    if (e.PlayerID == -1) {
        m_LocalPlayer = e.Player;
    }
    return true;
}

void RenderSystem::fillPointLights(std::list<std::shared_ptr<RenderJob>>& jobs, World* world)
{
    auto pointLights = m_World->GetComponents("PointLight");
    if (pointLights != nullptr) {
        for (auto& pointlightC : *pointLights) {
            bool visible = pointlightC["Visible"];
            if (!visible) {
                continue;
            }
            auto transformC = world->GetComponent(pointlightC.EntityID, "Transform");
            if (&transformC == nullptr) {
                continue;
            }

            std::shared_ptr<PointLightJob> pointLightJob = std::shared_ptr<PointLightJob>(new PointLightJob(transformC, pointlightC, m_World));
            jobs.push_back(pointLightJob);
        }
    }
}

void RenderSystem::fillDirectionalLights(std::list<std::shared_ptr<RenderJob>>& jobs, World* world)
{
    auto directionalLights = world->GetComponents("DirectionalLight");
    if (directionalLights != nullptr) {
        for (auto& directionalLightC : *directionalLights) {
            bool visable = directionalLightC["Visible"];
            if (!visable) {
                continue;
            }

            auto transformC = world->GetComponent(directionalLightC.EntityID, "Transform");
            if (&transformC == nullptr) {
                continue;
            }

            std::shared_ptr<DirectionalLightJob> directionalLightJob = std::shared_ptr<DirectionalLightJob>(new DirectionalLightJob(transformC, directionalLightC, m_World));
            jobs.push_back(directionalLightJob);
        }
    }
}

void RenderSystem::fillText(std::list<std::shared_ptr<RenderJob>>& jobs, World* world)
{
    auto texts = world->GetComponents("Text");
    if (texts == nullptr) {
        return;
    }
	
    for (auto& textComponent : *texts) {
        bool visible = textComponent["Visible"];
        if (!visible) {
            continue;
        }
        std::string resource = textComponent["Resource"];
        if (resource.empty()) {
            continue;
        }

        EntityWrapper entity(world, textComponent.EntityID);
        if (!isEntityVisible(entity)) {
            continue;
        }

        Font* font;
        try {
            font = ResourceManager::Load<Font>(resource);
        } catch (const std::exception&) {
            try {
                font = ResourceManager::Load<Font>("Fonts/DroidSans.ttf,16");
            } catch (const std::exception&) {
                continue;
            }
        }

        glm::mat4 modelMatrix = TransformSystem::ModelMatrix(textComponent.EntityID, world);
        std::shared_ptr<TextJob> textJob = std::shared_ptr<TextJob>(new TextJob(modelMatrix, font, textComponent));
        jobs.push_back(textJob);

    }
}

bool RenderSystem::OnInputCommand(const Events::InputCommand& e)
{
    return false;
}

void RenderSystem::Update(double dt)
{
    m_EventBroker->Process<RenderSystem>();

    // Update the current camera used for rendering
    if (m_CurrentCamera.Valid()) {
        m_Camera->SetPosition(TransformSystem::AbsolutePosition(m_CurrentCamera));
        m_Camera->SetOrientation(TransformSystem::AbsoluteOrientation(m_CurrentCamera));
    }

    RenderScene scene;
    scene.ShouldBlur = true;
    scene.Camera = m_Camera;
    scene.Viewport = Rectangle(1280, 720);

    auto cSceneLight = m_World->GetComponents("SceneLight");
    if (cSceneLight != nullptr && cSceneLight->begin() != cSceneLight->end()) {
        m_RenderFrame->Gamma = (double)(*cSceneLight->begin())["Gamma"];
        m_RenderFrame->Exposure = (double)(*cSceneLight->begin())["Exposure"];
        scene.AmbientColor = (glm::vec4)(*cSceneLight->begin())["AmbientColor"];
    }

    fillModels(scene.Jobs);
    fillPointLights(scene.Jobs.PointLight, m_World);
    //TODO: Make sure all objects needed are also sorted.
	scene.Jobs.OpaqueObjects.sort([](auto& a, auto& b) {return *a < *b; });
    fillSprites(scene.Jobs.SpriteJob, m_World);
    fillDirectionalLights(scene.Jobs.DirectionalLight, m_World);
    fillText(scene.Jobs.Text, m_World);
    m_RenderFrame->Add(scene);
   
}