// native_bridge/include/StateStore.h
// G2: persist bridge instrument state to a JSON file so a bridge respawn
// (crash, kill, restart) can reload instruments and continue playing.
#ifndef STATE_STORE_H
#define STATE_STORE_H

#include <cstdint>
#include <string>
#include <vector>

// One instrument slot persisted to disk.
struct InstrumentStateEntry {
    uint32_t channel = 0;
    int type = 0;                 // InstrumentType as int (0=VST3, 1=VST2, 2=SF2/SF3, 3=SFZ)
    std::string path;             // absolute plugin/soundfont path
    std::string presetBase64;     // VST3 serialized preset (empty for non-VST)
    uint32_t bank = 0;            // last bank select (SF2/SF3)
    uint32_t program = 0;         // last program change
};

// Whole-bridge snapshot written to disk.
struct BridgeStateSnapshot {
    std::vector<InstrumentStateEntry> instruments;
    bool playing = false;
    double playhead = 0.0;
};

// Hand-rolled JSON persistence (no external JSON dependency).
// File format: {"version":1,"playing":bool,"playhead":num,"instruments":[...]}
// Writes are atomic: temp file + rename (crash mid-write never corrupts state).
class StateStore {
public:
    // %APPDATA%/SonicForgeDAW/state/bridge_state.json (UTF-8).
    static std::string defaultPath();

    // Serialize snapshot to `path` (atomic). Returns false on IO error.
    static bool save(const BridgeStateSnapshot& snap, const std::string& path);
    // Read `path` into `out`; returns false if missing or unparsable.
    static bool load(BridgeStateSnapshot& out, const std::string& path);
    // Remove the state file (and any stale .tmp). Returns false if missing.
    static bool clear(const std::string& path);
};

#endif // STATE_STORE_H