#pragma once

#include <vector>

namespace fluidsim::port {

struct AudioFrame { float left{}, right{}; };
struct Vec3 { float x{}, y{}, z{}; };

// Flow-derivative sound source used by the C# two-stroke and pulse scenarios.
class SoundProcessor {
public:
    float gain{1.0f};
    explicit SoundProcessor(int sample_rate = 44100, float listener_distance = 1.0f);
    float process(float mass_flow_out);
private:
    float dt_{}, scale_factor_{}, lowpass_alpha_{}, derivative_alpha_{};
    float flow_lowpass_{}, previous_flow_{}, smooth_derivative_{};
};

class RadiationSource {
public:
    float flow_tau{0.005f}, smooth_tau{0.020f}, gain{15.0f};
    Vec3 pipe_end{}, pipe_axis{1.0f, 0.0f, 0.0f};
    Vec3 listener{0.0f, 0.0f, 1.5f}, listener_right{1.0f, 0.0f, 0.0f};
    float ear_spacing{0.18f}, head_shadow_cutoff{4000.0f}, speed_of_sound{343.0f};
    float directivity_balance{0.30f}, air_absorption_exponent{0.002f}, min_air_cutoff{1500.0f};

    explicit RadiationSource(int sample_rate = 44100);
    AudioFrame process(float mass_flow);
    float last_mono_pressure() const { return last_mono_pressure_; }

private:
    class DelayLine;
    class OnePole;
    int sample_rate_{};
    float dt_{}, flow_lp_{}, previous_flow_lp_{}, smooth_derivative_{};
    float last_mono_pressure_{};
    std::vector<float> left_delay_, right_delay_;
    std::size_t write_position_{}, left_offset_{}, right_offset_{};
    float air_filter_{}, shadow_left_{}, shadow_right_{};

    static float dot(Vec3 a, Vec3 b);
    static float length(Vec3 value);
    static Vec3 subtract(Vec3 a, Vec3 b);
    float one_pole(float input, float cutoff, float& state) const;
    float delayed(float input, std::vector<float>& buffer, std::size_t offset);
};

} // namespace fluidsim::port