#pragma once

// Gear ratio + final drive coupling between engine and wheels.
// Torque flows engine -> wheels; rpm flows wheels -> engine (reflected).
class Transmission {
public:
    void set_gear(int gear); // 0 = neutral, 1..N = forward gears
    int gear() const;

    double output_torque_nm(double engine_torque_nm) const;
    double reflected_engine_rpm(double wheel_rpm) const;

private:
    double ratio() const;

    int m_gear = 1;

    static constexpr double kFinalDrive = 3.42;
    static constexpr double kGearRatios[] = {0.0, 3.5, 2.1, 1.4, 1.0, 0.8};
    static constexpr int kNumGears =
        static_cast<int>(sizeof(kGearRatios) / sizeof(kGearRatios[0])) - 1;
};