#ifndef RENDER_SYSTEM
#define RENDER_SYSTEM
#include <iostream>
#include <vector>
#include <map>
#include <glm/glm.hpp>
#include "Structures.h"
const float skyboxVertices[] = {
    -1.0f,  1.0f, -1.0f, -1.0f, -1.0f, -1.0f,  1.0f, -1.0f, -1.0f,
     1.0f, -1.0f, -1.0f,  1.0f,  1.0f, -1.0f, -1.0f,  1.0f, -1.0f,
    -1.0f, -1.0f,  1.0f, -1.0f, -1.0f, -1.0f, -1.0f,  1.0f, -1.0f,
    -1.0f,  1.0f, -1.0f, -1.0f,  1.0f,  1.0f, -1.0f, -1.0f,  1.0f,
     1.0f, -1.0f, -1.0f,  1.0f, -1.0f,  1.0f,  1.0f,  1.0f,  1.0f,
     1.0f,  1.0f,  1.0f,  1.0f,  1.0f, -1.0f,  1.0f, -1.0f, -1.0f,
    -1.0f, -1.0f,  1.0f, -1.0f,  1.0f,  1.0f,  1.0f,  1.0f,  1.0f,
     1.0f,  1.0f,  1.0f,  1.0f, -1.0f,  1.0f, -1.0f, -1.0f,  1.0f,
    -1.0f,  1.0f, -1.0f,  1.0f,  1.0f, -1.0f,  1.0f,  1.0f,  1.0f,
     1.0f,  1.0f,  1.0f, -1.0f,  1.0f,  1.0f, -1.0f,  1.0f, -1.0f,
    -1.0f, -1.0f, -1.0f, -1.0f, -1.0f,  1.0f,  1.0f, -1.0f, -1.0f,
     1.0f, -1.0f, -1.0f, -1.0f, -1.0f,  1.0f,  1.0f, -1.0f,  1.0f
};
class Camera;
class Shader;
class FBO;
class VBO;
class VAO;
class Cubemap;
class Lighting;
class Renderable {
public:
    enum ShaderType {
        RigShader,
        MeshShader,
        ImageBoxShader,
        BoxShader,
        TextShader,
        ParticleShader
    };
    ShaderType shadertype = ShaderType::MeshShader;
    bool opaque = true;
    bool castshadow = false;
    Renderable();
    ~Renderable();
    void BindToRenderSystem();
    virtual void Render(Shader& ShaderProgram) {}
    virtual glm::vec3 GetWorldPosition() const { return glm::vec3(0.0f); }

    // A world space box around everything this draws. Without one it's never culled.
    virtual bool GetWorldBounds(BoundingBox& bounds) const { return false; }

    // Occlusion culling state, only the render system touches these
    unsigned int occlusionQuery = 0;
    bool occlusionPending = false;   // a query was sent and hasn't been read back yet
    bool occluded = false;           // the last answered query saw none of it
};
struct GraphicsSettings {
    bool bloom = true;
    bool shadows = true;        // the sun's shadow map
    bool lightShadows = true;   // spot and point light shadows
    bool vsync = true;
    bool culling = true;        // frustum and occlusion culling for opaque meshes and characters
};

struct HitboxDebugLine {
    glm::mat4 transform;
    glm::vec3 color;
};

class RenderSystem {
public:
    Lighting* lighting = nullptr;
    GraphicsSettings graphics;
    FBO* screenfbo = nullptr;
    FBO* shadowdepthmapfbo = nullptr;
    FBO* gBuffer = nullptr;
    unsigned int gPosition = 0;
    unsigned int gNormal = 0;
    unsigned int gAlbedo = 0;
    unsigned int gMaterial = 0;
    unsigned int gDepth = 0;
    unsigned int shadowDebugSampler = 0;
    FBO* localShadowFBO = nullptr;
    unsigned int localShadowAtlas = 0;
    FBO* bloomFBO[2] = { nullptr, nullptr };
    unsigned int bloomTextures[2] = { 0, 0 };
    int bloomWidth = 0;
    int bloomHeight = 0;
    int debugView = 0;  // 0 = final image, otherwise a debugMode in gbuffer_debug.frag
    unsigned int depthMaptexture = 0;
    unsigned int textureColorbuffer = 0;
    unsigned int rbo = 0;
    unsigned int SHADOW_RESOLUTION = 0;
    VAO* quadVAO = nullptr;  VBO* quadVBO = nullptr;
    VAO* skyboxVAO = nullptr;  VBO* skyboxVBO = nullptr;
    Shader* MeshShadowShader = nullptr;
    Shader* RigShadowShader = nullptr;
    Shader* SkyboxShader = nullptr;
    Shader* ScreenShader = nullptr;
    Shader* RigShader = nullptr;
    Shader* MeshShader = nullptr;
    Shader* GeometryShader = nullptr;
    Shader* GeometryRigShader = nullptr;
    Shader* DeferredLightingShader = nullptr;
    Shader* GBufferDebugShader = nullptr;
    Shader* BloomExtractShader = nullptr;
    Shader* BloomBlurShader = nullptr;
    Shader* ImageBoxShader = nullptr;
    Shader* BoxShader = nullptr;
    Shader* Text2DShader = nullptr;
    Shader* ParticleShader = nullptr;
    Shader* HitboxShader = nullptr;
    Cubemap* skybox = nullptr;
    unsigned int hitboxVAO = 0;
    unsigned int hitboxVBO = 0;
    std::vector<HitboxDebugLine> hitboxDebugLines;
    RenderSystem() {}
    void Initialize();
    void Resize(int width, int height);
    void Render(Camera& camera);
    void CycleDebugView();
    void SetHitboxDebugLines(const std::vector<HitboxDebugLine>& lines) { hitboxDebugLines = lines; }
    void AddRenderable(Renderable* r) { renderables.push_back(r); }
    void RemoveRenderable(Renderable* r) {
        for (int i = 0; i < (int)renderables.size(); i++) {
            if (renderables[i] == r) { renderables.erase(renderables.begin() + i); return; }
        }
        std::cout << "didn't find renderable to remove\n";
    }
    void RenderRenderable(Renderable* renderable, Camera& camera);
    std::vector<Renderable*> renderables;
private:
    void PrepareRigShader(Camera& camera);
    void PrepareMeshShader(Camera& camera);
    void PrepareParticleShader(Camera& camera);
    void PrepareBoxShader(Camera& camera);
    void PrepareImageBoxShader(Camera& camera);
    void PrepareTextShader(Camera& camera);
    void RenderTranslucent(Camera& camera, const glm::mat4& lightSpaceMatrix, const glm::vec3& camPos);
    void RenderHitboxDebug(Camera& camera);
    void AllocateGBuffer(int width, int height);
    void AllocateBloom(int width, int height);
    void RenderBloom();
    void RenderShadowCasters(const glm::mat4& lightSpaceMatrix);
    void RenderLocalShadows();
    void BindGBufferTextures(Shader* shader);
    void RenderGeometryPass(const glm::mat4& proj, const glm::mat4& view, const glm::vec3& camPos);
    bool IsVisible(Renderable* r, const glm::vec4 (&frustum)[6], const glm::vec3& camPos);
    void IssueOcclusionQueries(const glm::mat4& proj, const glm::mat4& view);
    std::vector<Renderable*> occlusionCandidates;   // drawn into the queries after the geometry pass
    void RenderLightingPass(const glm::vec3& camPos, const glm::mat4& lightSpaceMatrix);
    void RenderDebugView();
};
#endif