// native_bridge/src/Vst2Instrument.h
// VST2 (VST 2.4, 64-bit) instrument host. Clean-room ABI header
// (native_bridge/vestige/aeffect.h) — no Steinberg SDK, no LMMS code.
// GUI editor: supported for plugins with kEffectFlagsHasEditor (effEditOpen/
// effEditClose/effEditIdle); preset state is kept via effGetChunk/effSetChunk
// (fxp-style chunks).
#ifndef VST2_INSTRUMENT_H
#define VST2_INSTRUMENT_H

#include "INativeInstrument.h"

#include <string>
#include <vector>

class Vst2Instrument : public INativeInstrument {
public:
    Vst2Instrument();
    ~Vst2Instrument() override;

    bool loadPlugin(const std::string& path, double sampleRate);
    void setChannel(uint32_t channel) { channel_ = channel; }

    bool init(double sampleRate, uint32_t maxBlockSize) override;
    void selectProgram(uint32_t channel, uint32_t bank, uint32_t program) override;
    void noteOn(uint32_t channel, uint32_t pitch, float velocity, uint32_t sampleOffset) override;
    void noteOff(uint32_t channel, uint32_t pitch, uint32_t sampleOffset) override;
    void controlChange(uint32_t channel, uint32_t cc, uint32_t value) override;
    void programChange(uint32_t channel, uint32_t program) override;
    void pitchBend(uint32_t channel, uint32_t bend14) override;
    bool openGUI(void* parentWindowHandle) override;
    bool canOpenGUI() const override;
    bool attachView(void* parentWindowHandle) override;
    void closeGUI() override;
    bool hasAttachedView() const override;
    void guiIdle() override;
    void captureState() override;
    void restoreState() override;
    std::string serializeState() const override;
    void loadSerializedState(const std::string& base64) override;
    void processAudioBlock(float* outputL, float* outputR, uint32_t numSamples) override;

    // Accessors used by the audioMaster callback (same translation unit's
    // friend-ish helpers) without exposing AEffect* in the header.
    double sampleRate() const { return sampleRate_; }
    const std::string& pluginDir() const { return pluginDir_; }
    uint32_t maxBlockSize() const { return maxBlockSize_; }
    const void* effect() const;  // AEffect*; null until loaded
    // Host window the editor is attached to (attachView sets, closeGUI
    // clears). The audioMaster SizeWindow handler moves it via the hook.
    void* editorParent() const { return editorParent_; }
    // Register the SizeWindow hook (main.cpp posts the resize to the UI
    // worker). Probe builds never set it -> no-op.
    static void setResizeHook(void (*fn)(void* hwnd, int w, int h));
    // A14: register the plugin-MIDI-out sink (main.cpp writes SHM
    // midiOutQueue). Probe builds never set it -> no-op.
    static void setMidiOutHook(void (*fn)(uint8_t cmd, uint8_t ch, uint8_t d1,
                                           uint8_t d2, uint32_t deltaFrames));

private:
    void* state_;          // Vst2HostState* (pimpl — aeffect.h stays out of the header)
    std::string path_;
    std::string pluginDir_;
    double sampleRate_;
    uint32_t maxBlockSize_;
    bool loaded_;
    bool guiAttached_ = false;   // effEditOpen done, not yet effEditClose'd
    void* editorParent_ = nullptr;  // host window the editor is a child of
    uint32_t channel_ = 0;
    // scratch buffers for silent plugin inputs and extra output channels
    // (plugins with numOutputs > 2 need full pointer arrays)
    std::vector<float> inL_;
    std::vector<float> inR_;
    std::vector<float> extraOut_;
};

#endif // VST2_INSTRUMENT_H