#include <chrono>
#include "imgui.h"
#include "engine/simulation.h"
#include "gui/gui.h"

int main() {
    Gui gui;
    if (!gui.init()) return 1;

    Simulation sim;
    const double SIM_DT = 1.0 / 360.0;
    double accumulator = 0.0;

    auto last_time = std::chrono::steady_clock::now();

    while (gui.begin_frame()) {
        // 'r' resets the engine (rpm -> 0). false = don't auto-repeat while held.
        if (ImGui::IsKeyPressed(ImGuiKey_R, false)) {
            sim.engine().reset();
        }

        auto now = std::chrono::steady_clock::now();
        double frame_time = std::chrono::duration<double>(now - last_time).count();
        last_time = now;
        if (frame_time > 0.25) frame_time = 0.25; // clamp huge stalls (e.g. breakpoint)

        accumulator += frame_time;
        while (accumulator >= SIM_DT) {
            sim.step(SIM_DT);
            accumulator -= SIM_DT;
        }

        // Build this frame's display data. Only rpm is real right now;
        // the rest are placeholders until those models exist.
        EngineStats stats;
        stats.rpm = sim.engine().rpm();
        stats.fuel_consumption_lph = 0.0; // TODO: derive from fuel model
        stats.crank_power_kw = 0.0;       // TODO: torque_nm * rpm -> kW
        stats.output_heat_j = 0.0;        // TODO: energy balance / exhaust heat model

        stats.extra_stats.push_back({"Oil Temp", 0.0, "C"});
        stats.extra_stats.push_back({"Coolant Temp", 0.0, "C"});

        gui.render(stats);
        gui.end_frame();
    }

    gui.shutdown();
    return 0;
}