//
// StatsPanel.cpp：遥测与全局设置实现（原 main.cpp Scene Debug 搬迁）。
// 面板按 View / Scene / Rendering / Physics / Performance 分组——
// 环境贴图/环境光已实体化（Skybox/SkyLight 组件，Details 配置），
// 此处只留场景级 ClearColor。
//

#include "StatsPanel.h"
#include "Engine/ECS/Components.h"
#include "Engine/Physics/PhysicsWorld.h"
#include "Engine/Core/Time.h"

#include <imgui.h>
#include <glm/gtc/type_ptr.hpp>

using namespace Engine;   // f32（Engine/Core/Types.h）

void StatsPanel::Draw(const EditorContext& ctx)
{
    ImGui::Begin("Stats");

    auto& renderer = *ctx.renderer;
    auto& app = *ctx.app;

    // ---- View：看哪里（渲染目标）+ 相机位姿（跟随渲染源分派）----
    if (ImGui::CollapsingHeader("View", ImGuiTreeNodeFlags_DefaultOpen))
    {
        // 渲染源分派与 SceneRenderer::BuildFrame 同规则：PIE 内嵌播放
        // 或 kDisplayDirect 全屏预览 = primary 相机，否则编辑器相机
        const bool playing = ctx.playState && *ctx.playState;
        static const char* displayTarget[] = {
            "Fullscreen",
            "Viewport",
        };
        int mode = renderer.GetDisplayMode();
        if (ImGui::Combo("Display Target", &mode, displayTarget,
                         IM_ARRAYSIZE(displayTarget)))
        {
            renderer.SetDisplayMode(mode);
        }
        if ((playing || renderer.GetDisplayMode() == kDisplayDirect))
        {
            Engine::ECS::TransformComponent* camT = nullptr;
            if (ctx.scene->GetPrimaryCamera(&camT) != nullptr && camT != nullptr)
            {
                // world 位姿（相机实体可能挂父层级下）
                const glm::vec3& pos = camT->GetWorldPosition();
                ImGui::Text("Game Camera Pos");
                ImGui::Text("(%.3f, %.3f, %.3f)", pos.x, pos.y, pos.z);
            }
            else
            {
                ImGui::TextDisabled("(no primary camera)");
            }
        }
        else if (ctx.editorCamera)
        {
            const glm::vec3& pos = ctx.editorCamera->GetTransform().GetPosition();
            ImGui::Text("Editor Camera Pos");
            ImGui::Text("(%.3f, %.3f, %.3f)", pos.x, pos.y, pos.z);
        }
        else
        {
            ImGui::TextDisabled("(no camera)");
        }
    }

    // ---- Scene：模拟控制 + 场景级设置。PIE 暂停在主工具栏（UE 语义）----
    if (ImGui::CollapsingHeader("Scene", ImGuiTreeNodeFlags_DefaultOpen))
    {
        ImGui::ColorEdit4("Clear Color",
                          glm::value_ptr(ctx.scene->GetSettings().ClearColor));
    }

    // ---- Rendering：渲染管线参数与开关 ----
    if (ImGui::CollapsingHeader("Rendering", ImGuiTreeNodeFlags_DefaultOpen))
    {
        f32 exposure = renderer.GetExposure();
        if (ImGui::SliderFloat("Exposure", &exposure, 0.1f, 4.0f))
        {
            renderer.SetExposure(exposure);
        }
        bool aces = renderer.GetUseACES();
        if (ImGui::Checkbox("ACES", &aces))
        {
            renderer.SetUseACES(aces);
        }

        // Bloom：开关即显隐——勾上才显示参数
        bool bloom = renderer.GetBloomEnabled();
        if (ImGui::Checkbox("Bloom", &bloom))
        {
            renderer.SetBloomEnabled(bloom);
        }
        if (bloom)
        {
            f32 threshold = renderer.GetBloomThreshold();
            if (ImGui::SliderFloat("Threshold", &threshold, 0.0f, 8.0f,
                                   "%.1f", ImGuiSliderFlags_Logarithmic))
            {
                renderer.SetBloomThreshold(threshold);
            }
            f32 strength = renderer.GetBloomStrength();
            if (ImGui::SliderFloat("Strength", &strength, 0.0f, 2.0f))
            {
                renderer.SetBloomStrength(strength);
            }
        }

        // 无参数的纯开关：横排平铺
        bool shadows = renderer.GetShadowsEnabled();
        if (ImGui::Checkbox("Shadows", &shadows))
        {
            renderer.SetShadowsEnabled(shadows);
        }
        ImGui::SameLine();
        bool taa = renderer.GetTAAEnabled();
        if (ImGui::Checkbox("TAA", &taa))
        {
            renderer.SetTAAEnabled(taa);
        }
        ImGui::SameLine();
        bool lod = renderer.GetLodEnabled();
        if (ImGui::Checkbox("LOD", &lod))
        {
            renderer.SetLodEnabled(lod);   // 关 = 恒绘原网格
        }

        // 调试视图：单看某个 pass 的中间输出（类 UE pass debug）
        const auto& viewNames = renderer.GetDebugViewNames();
        int view = renderer.GetDebugView();
        if (ImGui::Combo("Debug View", &view, viewNames.data(),
                         static_cast<int>(viewNames.size())))
        {
            renderer.SetDebugView(view);
        }
    }

    // ---- Physics：调试可视化（collider/约束/重力/速度/加速度）----
    if (ImGui::CollapsingHeader("Physics"))
    {
        auto& physics = app.GetPhysics();
        u32 bits = physics.GetDebugDrawBits();
        bool master = bits != 0;
        if (ImGui::Checkbox("Debug Draw##Phys", &master))
        {
            bits = master ? kPhyDbgDefault : 0;
        }
        if (master)
        {
            ImGui::Indent();
            auto toggle = [&bits](const char* label, u32 bit) {
                bool on = (bits & bit) != 0;
                if (ImGui::Checkbox(label, &on))
                {
                    bits = on ? (bits | bit) : (bits & ~bit);
                }
            };
            toggle("Colliders", kPhyDbgColliders);
            toggle("Constraints", kPhyDbgConstraints);
            toggle("Gravity", kPhyDbgGravity);
            toggle("Velocity", kPhyDbgVelocity);
            toggle("Acceleration", kPhyDbgAccel);
            ImGui::Unindent();
        }
        physics.SetDebugDrawBits(bits);
        // 碰撞事件计数（最近一次步进；掉落物触地时应 > 0）
        ImGui::Text("contacts (frame): %zu", physics.GetEvents().size());
    }

    // ---- Performance：帧率控制 + GPU 遥测（默认折叠，不占面板高度）----
    if (ImGui::CollapsingHeader("Performance"))
    {
        bool vsync = app.GetVSync();
        if (ImGui::Checkbox("VSync", &vsync))
        {
            app.SetVSync(vsync);
            if (!vsync)
            {
                const f32 target = app.GetTargetFps();
                app.SetTargetFps(target);
            }
        }
        if (!vsync)
        {
            f32 target = app.GetTargetFps();
            if (ImGui::SliderFloat("Target FPS", &target, 24.0f, 360.0f, "%.0f"))
            {
                app.SetTargetFps(target);
            }
        }
        ImGui::Text("fps: %.1f  frame: %llu",
                1.0f / Time::Current().UnscaledDt(),
                static_cast<unsigned long long>(app.GetFrameCount()));

        ImGui::Separator();
        ImGui::Text("instances: %u main / %u shadow",
                    renderer.GetMainInstanceCount(),
                    renderer.GetShadowInstanceCount());
        if (renderer.GetInstancesTruncated())
        {
            ImGui::TextColored(ImVec4(1.0f, 0.3f, 0.3f, 1.0f),
                               "TRUNCATED: instance buffer full!");
        }
        const auto& names = renderer.GetPassNames();
        const auto& times = renderer.GetPassGpuMs();
        for (size_t i = 0; i < names.size() && i < times.size(); ++i)
        {
            ImGui::Text("  %-12s %.3f ms", names[i].c_str(), times[i]);
        }
    }

    ImGui::End();
}