//
// Created by atdunbg on 2026/9/20.
//
// SandboxApp：第一个基于 Application 框架的程序。
//
// main 的全部职责：定义一个 Application 派生类并运行它。
// 窗口、渲染器、事件泵、帧计时、场景容器全部由框架管理；
// 这里只写"程序逻辑"：创建实体、逐帧更新组件、事件响应。
//

#include <Engine/Core/Application.h>
#include <Engine/Core/Log.h>
#include <Engine/Core/Stats.h>
#include <Engine/ECS/Scene.h>
#include <Engine/ECS/EntityHandle.h>
#include <Engine/ECS/Components.h>
#include <Engine/Assets/AssetManager.h>

#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>

#include <GLFW/glfw3.h>

using namespace Engine;
using namespace Engine::ECS;

class SandboxApp final : public Application
{
public:
    SandboxApp()
        : Application("HelloVulkan", 1280, 720)
    {
    }

protected:
    // ---- 生命周期 ----

    void OnInit() override
    {
        Scene& scene = GetScene();

        // 模型资产（AssetManager 负责加载/缓存/生命周期，返回句柄）
        auto backpack = GetAssets().LoadModel("assets/models/backpack/backpack.obj");

        // 地面：接收阴影
        auto ground = GetAssets().CreatePlane(30.0f, "assets/textures/default.tga");
        auto groundEntity = scene.CreateEntity("Ground");
        groundEntity.AddComponent<TransformComponent>().world =
            glm::translate(glm::mat4(1.0f), glm::vec3(0.0f, -2.0f, 0.0f));
        groundEntity.AddComponent<MeshRendererComponent>(MeshRendererComponent{ground});

        // 相机实体（primary = 当前渲染视角）
        m_Camera = scene.CreateEntity("MainCamera");
        auto& camera = m_Camera.AddComponent<CameraComponent>();
        camera.primary = true;
        camera.camera.SetPosition(glm::vec3(0.0f, 0.0f, 7.0f));

        // 背包实体 × 3
        for (int i = 0; i < 3; ++i) {
            auto e = scene.CreateEntity("Backpack" + std::to_string(i));

            e.AddComponent<TransformComponent>().world = glm::translate(
                glm::mat4(1.0f),
                glm::vec3((i - 1) * 1.5f, 0.0f, 0.0f));

            e.AddComponent<MeshRendererComponent>(MeshRendererComponent{backpack});

            m_Spinners.push_back(e);
        }

        // 灯光实体（主光较平，影子拉长可见）
        scene.CreateEntity("KeyLight")
            .AddComponent<LightComponent>(
                LightComponent{glm::vec3(-0.5f, -0.6f, -0.35f),
                               glm::vec4(1.0f, 0.95f, 0.9f, 1.0f)});

        scene.CreateEntity("FillLight")
            .AddComponent<LightComponent>(
                LightComponent{glm::vec3(0.5f, -0.5f, 0.3f),
                               glm::vec4(0.3f, 0.5f, 1.0f, 0.8f)});
    }

    void OnUpdate(f32 deltaTime) override
    {
        m_Time += deltaTime;

        // 相机（WASD/Space/Shift 移动）
        m_Camera.GetComponent<CameraComponent>()
            .camera.Update(GetWindow(), deltaTime);

        // 旋转动画：直接写实体组件
        for (size_t i = 0; i < m_Spinners.size(); ++i) {
            f32 angle = m_Time * glm::radians(60.0f) + static_cast<f32>(i) * 0.7f;

            auto& transform = m_Spinners[i].GetComponent<TransformComponent>();
            glm::mat4 t = glm::translate(
                glm::mat4(1.0f),
                glm::vec3((static_cast<f32>(i) - 1.0f) * 1.5f, 0.0f, 0.0f));
            glm::mat4 r = glm::rotate(glm::mat4(1.0f), angle, glm::vec3(0.0f, 1.0f, 0.0f));
            glm::mat4 s = glm::scale(glm::mat4(1.0f), glm::vec3(0.5f));

            transform.world = t * r * s;
        }
    }

    // ---- 事件 ----

    void OnKeyPress(const Event& event) override
    {
        if (event.key == GLFW_KEY_F1) {
            STATS.PrintComparison();
        }
        if (event.key == GLFW_KEY_ESCAPE) {
            Close();
        }
    }

    void OnWindowResize(const Event& event) override
    {
        ENGINE_INFO("App: window resized to {}x{}", event.width, event.height);
    }

private:
    EntityHandle m_Camera{};                 // Scene::CreateEntity 之前为空
    std::vector<EntityHandle> m_Spinners;
    f32 m_Time = 0.0f;
};

int main()
{
    SandboxApp app;

    try {
        app.Run();
    }
    catch (const std::exception& e) {
        ENGINE_FATAL("Exception: {}", e.what());
        return -1;
    }

    return 0;
}