#ifndef EDITOR_HPP
#define EDITOR_HPP

#include "open_engine/ref_scope.hpp"
#include "panels/scene_hierarchy.hpp"
#include <open_engine.hpp>

#include <glm/ext/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>
#include <glm/matrix.hpp>
#include <entt/entt.hpp>
#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <cstdint>
#include <imgui.h>

namespace OpenEngine {

    class CameraController : public NativeScriptableEntity
    {
        public:
            void OnCreate()
            {
            };

            void OnUpdate()
            {
                auto delta = Time::DeltaTime();

                auto& transform = GetComponent<TransformComponent>();

                if (Input::IsKeyPressed(KeyCode::Up))
                    transform.transform[3][1] += 5.0 * delta;
                if (Input::IsKeyPressed(KeyCode::Down))
                    transform.transform[3][1] -= 5.0 * delta;
                if (Input::IsKeyPressed(KeyCode::Right))
                    transform.transform[3][0] += 5.0 * delta;
                if (Input::IsKeyPressed(KeyCode::Left))
                    transform.transform[3][0] -= 5.0 * delta;
            };

            void OnDestroy()
            {
            };
    };

    class EditorLayer : public Layer
    {
        public:
            EditorLayer()
                : Layer("editor_layer")/*,
                camera((float)Application::Get().GetWindow().GetWidth() /
                        Application::Get().GetWindow().GetHeight(), 1.0f)
                        */
        {
        }
            ~EditorLayer() {};

            entt::registry registry;

            void OnAttach() override
            {
                OE_PROFILE_FUNCTION();

                FramebufferSpecification specs;
                specs.width = 1280;
                specs.height = 720;

                framebuffer = FrameBuffer::Create(specs);

                scene = CreateRef<Scene>();

                sq_entity = scene->CreateEntity("square");

                sq_entity.AddComponents<TransformComponent>();
                sq_entity.AddComponents<SpriteRendererComponent>(glm::vec4(1.0f, 0.0f, 0.0f, 1.0f));

                camera_bis = scene->CreateEntity("Main camera");
                camera_bis.AddComponents<TransformComponent>();
                camera_bis.AddComponents<CameraComponent>();
                camera_bis.AddComponents<NativeScriptComponent>().Bind<CameraController>();

                scene_hierarchy.SetContext(scene);
            }

            void OnDetach() override
            {
            }

            void OnUpdate() override
            {
                FramebufferSpecification spec = framebuffer->GetSpecification();
                if (viewport_size.x > 0.0f && viewport_size.y > 0.0f &&
                        (spec.width != viewport_size.x || spec.height != viewport_size.y))
                {
                    framebuffer->Resize((uint32_t)viewport_size.x, (uint32_t)viewport_size.y);
                    //camera.OnResize(viewport_size.x, viewport_size.y);
                }

                {
                    OE_PROFILE_SCOPE("Setting up Rendering");
                    //camera.OnUpdate();
                    framebuffer->Bind();

                    scene->OnViewportResize((uint32_t)viewport_size.x, (uint32_t)viewport_size.y);
                }

                Renderer2D::ResetStats();
                RenderCommand::SetClearColor({0.11f, 0.11f, 0.15f, 1.0f});
                RenderCommand::Clear();

                //Renderer2D::BeginScene(camera.GetCamera());

                /*
                for (float y = -5.0f; y < 5.0f; y += 0.5f) {
                    for (float x = -5.0f; x < 5.0f; x += 0.5f) {

                        glm::vec4 gradient_color = {(x + 5.0f) / 10.0f, 0.3f, (y + 5.0f) / 10.0f, 1.0f};
                        Renderer2D::DrawQuad({{x, y, 0.0f}, glm::vec3(0.45f, 0.45f, 0.0f)}, gradient_color);
                    }
                }

                Transform tr5 = {
                    glm::vec3(world_pos_cursor.x, world_pos_cursor.y, 0.9f),
                    glm::vec3(0.1f, 0.1f, 0.0f), 0.0f};

                Renderer2D::DrawQuad(tr5, {1, 1, 1, 1});
                */

                scene->OnUpdate();

                //Renderer2D::EndScene();

                framebuffer->Unbind();
            }

            void OnEvent(Event& event) override
            {
                OE_PROFILE_FUNCTION();
                //camera.OnEvent(event);
            }

            float remap(float value, float minInput, float maxInput, float minOutput, float maxOutput) {
                // 1. Normalize the input to a 0.0 - 1.0 range
                float t = (value - minInput) / (maxInput - minInput);

                // 2. Use glm::mix to interpolate between the output range
                return glm::mix(minOutput, maxOutput, t);
            }

            glm::vec3 ScreenToWorld(
                    float screenX, 
                    float screenY, 
                    float screenZ,  // depth value (0.0 = near plane, 1.0 = far plane)
                    const glm::mat4& view, 
                    const glm::mat4& projection,
                    int viewportWidth,
                    int viewportHeight)
            {
                // 1. Convert screen coordinates to normalized device coordinates (NDC)
                // Screen space: origin at top-left, Y points down
                // NDC space: origin at center, range [-1, 1] for x and y

                float x = (2.0f * screenX) / viewportWidth - 1.0f;
                float y = 1.0f - (2.0f * screenY) / viewportHeight;  // Flip Y
                float z = 2.0f * screenZ - 1.0f;  // [0,1] -> [-1,1]

                glm::vec4 clipCoords(x, y, z, 1.0f);

                // 2. Transform from clip space to view space
                glm::mat4 invProjection = glm::inverse(projection);
                glm::vec4 viewCoords = invProjection * clipCoords;

                // 3. Transform from view space to world space
                glm::mat4 invView = glm::inverse(view);
                glm::vec4 worldCoords = invView * viewCoords;

                // 4. Perspective divide
                if (worldCoords.w != 0.0f) {
                    worldCoords /= worldCoords.w;
                }

                return glm::vec3(worldCoords);
            };

            void DrawViewport()
            {
                ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2{ 0, 0 });

                ImGui::Begin("Viewport");
                bool focused = ImGui::IsWindowFocused();
                bool hovered = ImGui::IsWindowHovered();
                Application::Get().GetImGuiLayer()->SetBlockEvents(!focused || !hovered);

                ImVec2 viewport_panel_size = ImGui::GetContentRegionAvail();

                viewport_size = { viewport_panel_size.x, viewport_panel_size.y };

                ImVec2 imgui_cursor_position = ImGui::GetCursorScreenPos();
                auto pair_position = Input::GetMousePosition();
                glm::vec2 mouse_position = { pair_position.first, pair_position.second };

                int max_x = viewport_size.x + imgui_cursor_position.x;
                int max_y = viewport_size.y + imgui_cursor_position.y;

                if (focused || hovered) {
                    float x = mouse_position.x - imgui_cursor_position.x;
                    float y = mouse_position.y - imgui_cursor_position.y;

                    /*
                    auto& cam = camera.GetCamera();
                    world_pos_cursor = ScreenToWorld(x, y, 0.0f,
                            cam.GetViewMatrix(),
                            cam.GetProjectionMatrix(),
                            viewport_size.x,
                            viewport_size.y);
                            */
                }

                uint32_t texture_id = framebuffer->GetColorAttachmentRendererID();
                ImGui::Image((void*)(uint64_t)texture_id, ImVec2{ viewport_size.x, viewport_size.y }, ImVec2{ 0, 1 }, ImVec2{ 1, 0 });

                ImGui::End();
                ImGui::PopStyleVar();
            };

            void DrawStats()
            {
                auto stats = Renderer2D::GetStats();
                static float time = 0;

                time += Time::DeltaTime();

                if (time >= 1) {
                    time = 0;
                }

                ImGui::Begin("Statistics");
                ImGui::Text("FPS: %0.0f", 1 / Time::DeltaTime());
                ImGui::Text("Renderer2D:");
                ImGui::Text("\t\tDraw calls: %d", stats.draw_calls);
                ImGui::Text("\t\tQuad count: %d", stats.quad_count);
                ImGui::Text("\t\tVertices count: %d", stats.GetToralVertexCount());
                ImGui::Text("\t\tIndices count: %d", stats.GetToralIndexCount());

                /*
                   for (auto& result : profiling_results)
                   {
                   char label[50];
                   strcpy(label, "%.3fms ");
                   strcat(label, result.name);
                   ImGui::Text(label, result.duration);
                   }

                   profiling_results.clear();
                   */

                ImGui::End();
            };

            void OnImGuiRender() override
            {
                OE_PROFILE_FUNCTION();

                ImGui::DockSpaceOverViewport();

                DrawStats();
                scene_hierarchy.OnImGuiRender();
                DrawViewport();

                ImGui::ShowDemoWindow();
            };

        private:
            std::vector<Time::ProfilingResult> profiling_results;

            glm::vec2 world_pos_cursor = { 0.0f, 0.0f };

            glm::vec2 viewport_size = { 0.0f, 0.0f };
            Ref<OpenEngine::FrameBuffer> framebuffer;
            SceneHierarchy scene_hierarchy;
            //OrthographicCameraController camera;

            Entity camera_bis;

            Ref<Scene> scene;
            Entity sq_entity;
    };
}

class EditorApp : public OpenEngine::Application
{
    public:
        EditorApp();
        ~EditorApp();
};

#endif // EDITOR_HPP