#pragma once

#include "FluidSim/Fluid.hpp"
#include <array>
#include <cstdint>

namespace fluidsim::port {

// RHB31/VZ21-size mean-line approximation. Geometry, losses and coefficients
// are estimates, not a digitized or validated manufacturer performance map.
struct TurboConfig {
    static TurboConfig gt17(); // estimated Saab GT1752-size calibration
    double shaft_inertia{4e-6}; // kg m^2, compressor+turbine+shaft rigid rotor
    double compressor_radius{.018}, turbine_radius{.0135};
    double compressor_head_coefficient{.60}, compressor_efficiency{.65};
    double turbine_peak_efficiency{.65}, turbine_optimum_speed_ratio{.70};
    double compressor_effective_area{110e-6}, turbine_effective_area{100e-6};
    double bearing_viscous{1e-7}, windage{2e-11}; // Nm/(rad/s), Nm/(rad/s)^2
    // Estimated pressure-can/spring wastegate. Set maximum lift to zero for a
    // pure ungated turbo bench test. This changes bypass AREA, never boost.
    double gate_diaphragm_area{8e-4}, gate_spring_preload{40}, gate_spring_stiffness{6000};
    double gate_damping{120}, gate_diameter{.014}, gate_maximum_lift{.004};
    double reference_pressure{101325};
    float compressor_inlet_volume{20e-6f}, compressor_outlet_volume{30e-6f};
    float turbine_inlet_volume{30e-6f}, turbine_outlet_volume{20e-6f};
    std::array<float, 4> connection_diameters{.024f, .024f, .025f, .026f};
};

struct TurboSnapshot {
    double rpm{}, angle{}, shaft_energy{}, turbine_power{}, compressor_power{}, bearing_power{};
    double compressor_flow{}, turbine_flow{}, compressor_pressure_ratio{}, turbine_pressure_ratio{};
    double turbine_inlet_pressure{}, turbine_outlet_pressure{}, charge_pressure{}, charge_temperature{};
    double bearing_heat{}, energy_residual{};
    std::uint64_t limited_transfers{};
    double wastegate_flow{}, wastegate_lift{};
};

// Four pressure-storage nodes joined by turbine/nozzle and centrifugal-pump
// characteristics. Existing pipe orifices exchange conserved mass/enthalpy.
// The whole turbo is ONE solver component; do not also register its volumes.
class Turbocharger final : public Component {
public:
    explicit Turbocharger(TurboConfig config = {});
    const TurboConfig config;
    Volume0D compressor_inlet, compressor_outlet, turbine_inlet, turbine_outlet;
    Port& compressor_inlet_port;
    Port& compressor_outlet_port;
    Port& turbine_inlet_port;
    Port& turbine_outlet_port;

    void connect(BoundarySystem& boundaries, const std::vector<Pipe1D>& pipes,
                 int compressor_in, bool compressor_in_left, int compressor_out, bool compressor_out_left,
                 int turbine_in, bool turbine_in_left, int turbine_out, bool turbine_out_left);
    std::vector<Port*> ports() override;
    void update_state(float dt) override;
    TurboSnapshot snapshot() const;
    double omega() const { return omega_; }
    double shaft_energy() const { return .5*config.shaft_inertia*omega_*omega_; }
    double fluid_energy() const;
    // Intended for standalone initialization/tests, never an imposed running speed.
    void set_initial_rpm(double rpm);
    void set_wastegate_duty(double duty) { gate_duty_ = std::isfinite(duty) ? std::clamp(duty, 0., .85) : 0.; }

private:
    std::array<Port*, 4> internal_;
    std::array<float, 4> connection_areas_{};
    double omega_{}, angle_{}, bearing_heat_{};
    double turbine_power_{}, compressor_power_{}, bearing_power_{}, energy_residual_{};
    double compressor_flow_{}, turbine_flow_{};
    double wastegate_flow_{}, wastegate_lift_{};
    std::uint64_t limited_transfers_{};
    bool connected_{};
    double gate_duty_{}; // pneumatic bleed fraction; zero restores spring boost
    static double nozzle(double upstream_pressure, double upstream_temperature,
                         double downstream_pressure, double area);
    double transfer_flow(Volume0D& inlet, Volume0D& outlet, Port& inlet_external,
                         Port& outlet_external, double requested, double dt);
    static void set_transfer(Volume0D& inlet, Volume0D& outlet, Port& inlet_internal,
                             Port& outlet_internal, double flow, double shaft_work, double dt);
};
} // namespace fluidsim::port