#pragma once

#include <string>
#include <vector>

struct GLFWwindow;

// One row for the extensible right-hand stats list (oil temp, coolant
// temp, etc.) — push more entries onto EngineStats::extra_stats as the
// sim grows, no Gui changes needed.
struct StatEntry {
    std::string label;
    double value;
    std::string unit;
};

// Plain data the GUI reads each frame. The GUI knows nothing about
// Engine/Transmission/Vehicle — main.cpp fills this in from Simulation.
struct EngineStats {
    double rpm = 0.0;
    double redline_rpm = 6500.0;  // tach gauge: start of red zone
    double max_rpm = 8000.0;      // tach gauge: full scale

    double fuel_consumption_lph = 0.0;
    double crank_power_kw = 0.0;
    double output_heat_j = 0.0;

    std::vector<StatEntry> extra_stats;
};

class Gui {
public:
    bool init();                     // create window + ImGui context
    bool begin_frame();               // returns false when the window should close
    void render(const EngineStats& stats);
    void end_frame();                 // swap buffers
    void shutdown();

private:
    GLFWwindow* m_window = nullptr;
};