// native_bridge/include/FxRealtimeIPC.h
// SHM layout cho fx_vst_bridge --realtime-fx (VST FX xử lý realtime, cloud-FX
// loop): engine (Python) tạo mapping, bridge mở và chạy vòng lặp audio.
// Tất cả field u32/float (4-byte) — KHÔNG padding — mirror chính xác bằng
// ctypes trong app/core/fx_realtime.py.
#pragma once
#include <cstdint>

#define FXRT_MAGIC 0x46585254u      // "FXRT"
#define FXRT_BLOCK 256
#define FXRT_IN_SLOTS 4             // engine -> bridge
#define FXRT_OUT_SLOTS 8            // bridge -> engine
#define FXRT_CTRL_SLOTS 8           // SET_PARAM commands (engine -> bridge)
#define FXRT_LAT_SLOTS 8            // REPORT_LATENCY reports (bridge -> engine)
#define FXRT_STATE_STARTING 0
#define FXRT_STATE_READY 1
#define FXRT_STATE_ERROR 2

// Header 72 bytes (18 u32) — giữ thứ tự khớp fx_realtime.py.
struct FxRealtimeHeader {
    volatile uint32_t magic;
    volatile uint32_t state;
    uint32_t sampleRate;
    uint32_t blockSize;
    volatile uint32_t running;      // engine set 0 → bridge thoát
    volatile uint32_t heartbeat;    // bridge tăng mỗi 100ms (watchdog)
    volatile uint32_t inWrite;      // producer: engine
    volatile uint32_t inRead;       // consumer: bridge
    uint32_t inSlots;
    volatile uint32_t outWrite;     // producer: bridge
    volatile uint32_t outRead;      // consumer: engine
    uint32_t outSlots;
    volatile uint32_t ctrlWrite;    // producer: engine (SET_PARAM ring)
    volatile uint32_t ctrlRead;     // consumer: bridge
    uint32_t ctrlSlots;
    volatile uint32_t latWrite;     // producer: bridge (REPORT_LATENCY ring)
    volatile uint32_t latRead;      // consumer: engine
    uint32_t latSlots;
};

// SET_PARAM: {slot_idx, key[16], value} — 24 bytes.
struct FxCtrlCmd {
    volatile uint32_t slot;
    char key[16];
    volatile float value;
};
static_assert(sizeof(FxCtrlCmd) == 24, "FxCtrlCmd must be 24 bytes");

// REPORT_LATENCY: {slot_idx, samples} — 8 bytes.
struct FxLatReport {
    volatile uint32_t slot;
    volatile uint32_t samples;
};
static_assert(sizeof(FxLatReport) == 8, "FxLatReport must be 8 bytes");

struct FxRealtimeIPC {
    FxRealtimeHeader h;
    float inL[FXRT_IN_SLOTS][FXRT_BLOCK];
    float inR[FXRT_IN_SLOTS][FXRT_BLOCK];
    float outL[FXRT_OUT_SLOTS][FXRT_BLOCK];
    float outR[FXRT_OUT_SLOTS][FXRT_BLOCK];
    FxCtrlCmd ctrl[FXRT_CTRL_SLOTS];
    FxLatReport lat[FXRT_LAT_SLOTS];
};