#pragma once

#include <JuceHeader.h>

namespace serum
{

// ===========================================================================
// ADSR envelope with curve tension. Durations are in seconds; the sustain
// level is 0..1. Retriggering (noteOn while active) starts from the current
// value for click-free legato behaviour.
// ===========================================================================
class Envelope
{
public:
    void prepare (double sampleRate) { sr = sampleRate; reset(); }
    void reset();

    void noteOn();
    void noteOff();

    void setParams (float attackSec, float decaySec, float sustain, float releaseSec, float curve);

    float process() noexcept;       // advance one sample and return the value
    float getValue() const noexcept { return value; }
    bool  isActive() const noexcept { return stage != Stage::Idle; }

    // Snapshot for GUI rendering.
    struct Shape { float attack = 0, decay = 0, sustain = 0, release = 0, curve = 0.5f; };
    Shape getShape() const noexcept { return shape; }

private:
    enum class Stage { Idle, Attack, Decay, Sustain, Release };

    Stage  stage = Stage::Idle;
    double sr = 44100.0;

    float  value = 0.0f;
    float  startValue = 0.0f, endValue = 0.0f;
    double elapsed = 0.0, duration = 0.0;
    double attackShape = 1.0, decayShape = 1.0;

    float  sustain = 0.7f;
    double attackSamples = 0.0, decaySamples = 0.0, releaseSamples = 0.0;
    Shape  shape;
};

} // namespace serum