#ifndef FAN_RENDERER_HPP_
#define FAN_RENDERER_HPP_

#include "scene.hpp"
#include "camera.hpp"
#include "uniformbuffer.hpp"

namespace Fan
{

class Renderer
{
public:
    // init() needs a current GL context and also initializes the ResourceCache.
    // shutdown() must run before the window (and its context) is destroyed
    static bool init();
    static void shutdown();

    static void set_viewport(int x, int y, int width, int height);
    static void set_clear_color(const glm::vec4& color);
    static void set_wireframe(bool enabled); // Global, stays on until disabled

    static void clear();

    // Draws into the currently bound framebuffer without clearing it.
    // screen_width and screen_height only set the camera aspect ratio
    static void draw_scene(const Scene& scene, const Camera& camera,
                           int screen_width, int screen_height);

    // debug_shader needs u_model, u_view_projection and u_color. default_mesh is
    // drawn for entities without a mesh and for lights. Disables wireframe when done
    static void draw_debug_wireframes(const Scene& scene, const Camera& camera,
                                      int screen_width, int screen_height,
                                      const Rc<Shader>& debug_shader,
                                      const Rc<Mesh>& default_mesh);

private:
    static Rc<UniformBuffer> s_camera_ubo;
    static Rc<UniformBuffer> s_light_ubo;

    static void update_global_data(const Scene& scene, const Camera& camera,
                                   int screen_width, int screen_height);

    struct CameraData {
        glm::mat4 view;
        glm::mat4 projection;
        glm::vec4 position; // w unused, std140 pads vec3 to 16 bytes anyway
    };

    // Maps to Fan::DirectionalLight
    struct DirectionalLightData {
        glm::vec4 direction;
        glm::vec4 ambient;
        glm::vec4 diffuse;
        glm::vec4 specular;
    };

    // Maps to Fan::PointLight
    struct PointLightData {
        glm::vec4 position;
        glm::vec4 ambient;
        glm::vec4 diffuse;
        glm::vec4 specular;
        glm::vec4 attenuation; // x = constant, y = linear, z = quadratic
    };

    // Maps to Fan::SpotLight
    struct SpotLightData {
        glm::vec4 position;
        glm::vec4 direction;
        glm::vec4 ambient;
        glm::vec4 diffuse;
        glm::vec4 specular;
        glm::vec4 attenuation; // x = constant, y = linear, z = quadratic
        glm::vec4 cut_offs;    // x = cut_off (cos), y = outer_cut_off (cos)
    };

    struct LightEnvironmentData {
        DirectionalLightData dir_light;

        int active_point_lights;
        int active_spot_lights;
        int _padding[2]; // Pad the 8 bytes of integers to a 16-byte boundary

        PointLightData point_lights[MAX_POINT_LIGHTS];
        SpotLightData spot_lights[MAX_SPOT_LIGHTS];
    };
};

} // namespace Fan

#endif // FAN_RENDERER_HPP_