//
// GamepadPanel.cpp：手柄输入可视化回显（极简手柄视图）。
//
// 一块画布 = 手柄俯视图：顶部扳机条 + 肩键，左上左摇杆、左下十字键、
// 右上 ABXY（Xbox 语义色）、右下右摇杆，中央 Back/Guide/Start 小键。
// 按下即亮蓝（面键亮语义色），无数值无卡片——位置即实体，一眼对上
// 手里的手柄。数据源 = Window::PollGamepad（GLFW 原始轴值/按键）。
//

#include "GamepadPanel.h"

#include <Engine/Core/Window.h>

#include <imgui.h>

#include <cmath>

namespace {

    // GLFW 标准布局下标
    enum PadBtn {
        kA = 0, kB = 1, kX = 2, kY = 3,
        kLB = 4, kRB = 5, kBack = 6, kStart = 7, kGuide = 8,
        kLS = 9, kRS = 10, kUp = 11, kRight = 12, kDown = 13, kLeft = 14,
    };

    constexpr ImU32 kLit = IM_COL32(90, 170, 250, 255);       // 按下亮蓝
    constexpr ImU32 kFill = IM_COL32(52, 52, 60, 255);        // 暗态填充
    constexpr ImU32 kEdge = IM_COL32(104, 104, 114, 255);     // 暗态描边
    constexpr ImU32 kTxt = IM_COL32(215, 215, 220, 255);      // 标签文字

    // 块状键（肩键 / Back / Start）
    void Block(ImDrawList* dl, const ImVec2& c, float w, float h,
               const char* label, bool pressed)
    {
        const ImVec2 mn(c.x - w * 0.5f, c.y - h * 0.5f);
        const ImVec2 mx(c.x + w * 0.5f, c.y + h * 0.5f);
        dl->AddRectFilled(mn, mx, pressed ? kLit : kFill, 5.0f);
        dl->AddRect(mn, mx, pressed ? IM_COL32(160, 210, 255, 255) : kEdge,
                    5.0f);
        const ImVec2 ts = ImGui::CalcTextSize(label);
        dl->AddText(ImVec2(c.x - ts.x * 0.5f, c.y - ts.y * 0.5f), kTxt, label);
    }

    // 圆键（Guide）
    void Circle(ImDrawList* dl, const ImVec2& c, float r, const char* label,
                bool pressed)
    {
        dl->AddCircleFilled(c, r, pressed ? kLit : kFill);
        dl->AddCircle(c, r, pressed ? IM_COL32(160, 210, 255, 255) : kEdge, 0,
                      1.5f);
        const ImVec2 ts = ImGui::CalcTextSize(label);
        dl->AddText(ImVec2(c.x - ts.x * 0.5f, c.y - ts.y * 0.5f), kTxt, label);
    }

    // Xbox 语义色面键
    void Face(ImDrawList* dl, const ImVec2& c, float r, char label,
              bool pressed)
    {
        ImU32 col;
        switch (label)
        {
            case 'A': col = IM_COL32(32, 150, 40, 255); break;
            case 'B': col = IM_COL32(200, 45, 45, 255); break;
            case 'X': col = IM_COL32(50, 110, 220, 255); break;
            default:  col = IM_COL32(225, 185, 40, 255); break;
        }
        dl->AddCircleFilled(c, r, pressed ? col : IM_COL32(col & 0xFF,
                                                           (col >> 8) & 0xFF,
                                                           (col >> 16) & 0xFF,
                                                           60));
        dl->AddCircle(c, r, pressed ? col : kEdge, 0, 2.0f);
        const ImVec2 ts = ImGui::CalcTextSize(&label, &label + 1);
        dl->AddText(ImVec2(c.x - ts.x * 0.5f, c.y - ts.y * 0.5f),
                    pressed ? IM_COL32(255, 255, 255, 255) : kTxt, &label);
    }

    // 摇杆画布（底座 + 死区圈 + 轴点）
    void Stick(ImDrawList* dl, const ImVec2& c, float r, float ax, float ay,
               float deadzone)
    {
        dl->AddCircleFilled(c, r, IM_COL32(32, 32, 37, 255));
        dl->AddCircle(c, r, kEdge, 0, 1.5f);
        dl->AddCircle(c, r * deadzone, IM_COL32(90, 140, 210, 110), 0, 1.2f);
        dl->AddLine(ImVec2(c.x - r * 0.93f, c.y), ImVec2(c.x + r * 0.93f, c.y),
                    IM_COL32(50, 50, 58, 255), 1.0f);
        dl->AddLine(ImVec2(c.x, c.y - r * 0.93f), ImVec2(c.x, c.y + r * 0.93f),
                    IM_COL32(50, 50, 58, 255), 1.0f);
        const float mag = std::sqrt(ax * ax + ay * ay);
        const float cl = (mag > 1.0f) ? 1.0f / mag : 1.0f;
        const ImVec2 pt(c.x + ax * cl * (r - 8.0f),
                        c.y + ay * cl * (r - 8.0f));
        if (mag > deadzone)
        {
            dl->AddCircleFilled(pt, 10.0f, IM_COL32(90, 170, 250, 70));
        }
        dl->AddCircleFilled(pt, 7.0f,
                            mag > deadzone ? kLit
                                           : IM_COL32(140, 140, 148, 255));
    }

    // 十字键（真十字形，按下臂亮）
    void Dpad(ImDrawList* dl, const ImVec2& c, float arm, float w,
              const bool* b)
    {
        const ImVec2 l0(c.x - arm, c.y - w * 0.5f);
        const ImVec2 l1(c.x, c.y + w * 0.5f);
        const ImVec2 r0(c.x, c.y - w * 0.5f);
        const ImVec2 r1(c.x + arm, c.y + w * 0.5f);
        const ImVec2 u0(c.x - w * 0.5f, c.y - arm);
        const ImVec2 u1(c.x + w * 0.5f, c.y);
        const ImVec2 d0(c.x - w * 0.5f, c.y);
        const ImVec2 d1(c.x + w * 0.5f, c.y + arm);
        dl->AddRectFilled(l0, l1, b[kLeft] ? kLit : kFill, 4.0f);
        dl->AddRectFilled(r0, r1, b[kRight] ? kLit : kFill, 4.0f);
        dl->AddRectFilled(u0, u1, b[kUp] ? kLit : kFill, 4.0f);
        dl->AddRectFilled(d0, d1, b[kDown] ? kLit : kFill, 4.0f);
        dl->AddRect(l0, l1, kEdge, 4.0f);
        dl->AddRect(r0, r1, kEdge, 4.0f);
        dl->AddRect(u0, u1, kEdge, 4.0f);
        dl->AddRect(d0, d1, kEdge, 4.0f);
    }

    // 线性扳机条（GLFW -1..1 → 0..1 填充）
    void Trigger(ImDrawList* dl, const ImVec2& mn, const ImVec2& mx,
                 float raw)
    {
        dl->AddRectFilled(mn, mx, IM_COL32(32, 32, 37, 255), 4.0f);
        const float t = (raw + 1.0f) * 0.5f;
        if (t > 0.02f)
        {
            dl->AddRectFilled(mn, ImVec2(mn.x + (mx.x - mn.x) * t, mx.y),
                              IM_COL32(235, 120, 55, 255), 4.0f);
        }
        dl->AddRect(mn, mx, kEdge, 4.0f);
    }

} // namespace

void GamepadPanel::Draw(const EditorContext& ctx)
{
    if (!m_Open)
    {
        return;
    }
    if (!ImGui::Begin("Gamepad", &m_Open))
    {
        ImGui::End();
        return;
    }

    Engine::GamepadState gp;
    const bool connected =
        ctx.app && ctx.app->GetWindow().PollGamepad(gp);

    if (!connected)
    {
        ImGui::TextColored(ImVec4(0.60f, 0.60f, 0.60f, 1.0f),
                           "○ Not connected (JOYSTICK_1)");
        ImGui::End();
        return;
    }
    ImGui::TextColored(ImVec4(0.40f, 0.85f, 0.40f, 1.0f), "● Connected");
    ImGui::Spacing();

    // ---- 手柄画布（固定尺寸，元素 = 手柄真实位置；无背景板）----
    constexpr float kW = 440.0f, kH = 262.0f;
    constexpr float kDead = 0.15f;   // = InputMap kRadialDeadZone
    ImGui::BeginChild("pad", ImVec2(kW, kH), false);
    ImDrawList* dl = ImGui::GetWindowDrawList();
    const ImVec2 o = ImGui::GetWindowPos();
    auto C = [&](float x, float y) { return ImVec2(o.x + x, o.y + y); };

    // 顶部：线性扳机条 + 肩键
    Trigger(dl, C(52, 8), C(122, 20), gp.axes[4]);           // LT
    Trigger(dl, C(kW - 122, 8), C(kW - 52, 20), gp.axes[5]); // RT
    Block(dl, C(78, 40), 76.0f, 20.0f, "LB", gp.buttons[kLB]);
    Block(dl, C(kW - 78, 40), 76.0f, 20.0f, "RB", gp.buttons[kRB]);

    // 左上：左摇杆｜左下：十字键（向右错开——真实手柄摇杆与十字不对齐）
    Stick(dl, C(76, 118), 46.0f, gp.axes[0], gp.axes[1], kDead);
    Dpad(dl, C(128, 210), 36.0f, 24.0f, gp.buttons);

    // 中央：Back / Guide / Start
    Block(dl, C(184, 74), 40.0f, 16.0f, "Back", gp.buttons[kBack]);
    Circle(dl, C(220, 58), 13.0f, "G", gp.buttons[kGuide]);
    Block(dl, C(256, 74), 40.0f, 16.0f, "Start", gp.buttons[kStart]);

    // 右上：ABXY 菱形｜右下：右摇杆（对称错开，向中心收）
    const ImVec2 fc = C(360, 118);
    Face(dl, ImVec2(fc.x, fc.y - 24), 17.0f, 'Y', gp.buttons[kY]);
    Face(dl, ImVec2(fc.x - 24, fc.y), 17.0f, 'X', gp.buttons[kX]);
    Face(dl, ImVec2(fc.x + 24, fc.y), 17.0f, 'B', gp.buttons[kB]);
    Face(dl, ImVec2(fc.x, fc.y + 24), 17.0f, 'A', gp.buttons[kA]);
    Stick(dl, C(312, 210), 46.0f, gp.axes[2], gp.axes[3], kDead);

    ImGui::EndChild();
    ImGui::End();
}