#pragma once

#include <Arduino.h>

#define MAX_FRAME_SIZE  176   // +4 for transport codes (region scoping)

class BaseSerialInterface {
protected:
  BaseSerialInterface() { }

public:
  virtual void enable() = 0;
  virtual void disable() = 0;
  virtual bool isEnabled() const = 0;

  virtual bool isConnected() const = 0;
  virtual void loop() {};

  virtual bool isReadBusy() const = 0;
  virtual bool isWriteBusy() const = 0;
  // True while application-level transport work still needs loop service.
  // Backends whose busy methods are throttling/high-water signals should
  // override this with their actual queue state.
  virtual bool hasPendingIO() const { return isReadBusy() || isWriteBusy(); }
  // Returns true once for each pending Bluetooth pairing prompt. Non-BLE
  // transports keep the default implementation so UI code can poll safely.
  virtual bool takePairingRequest() { return false; }
  // Capture and later address the transport which supplied the current
  // command. Multi-transport implementations override these so asynchronous
  // replies do not follow a newer client's command or fall back to broadcast.
  virtual BaseSerialInterface* captureReplyRoute() { return this; }
  virtual bool isReplyRouteAvailable(BaseSerialInterface* route) const {
    return route == this && isEnabled() && isConnected();
  }
  virtual bool isReplyRouteWriteBusy(BaseSerialInterface* route) const {
    return !isReplyRouteAvailable(route) || isWriteBusy();
  }
  virtual size_t writeFrameToRoute(BaseSerialInterface* route,
                                   const uint8_t src[], size_t len) {
    return route == this ? writeFrame(src, len) : 0;
  }
  // Multi-transport implementations can pin a sequence of response frames to
  // the interface which supplied the current command. Single transports have
  // nothing to route, so their default implementations are no-ops.
  virtual void lockReplyRoute() {}
  virtual void unlockReplyRoute() {}
  virtual size_t writeFrame(const uint8_t src[], size_t len) = 0;
  virtual size_t checkRecvFrame(uint8_t dest[]) = 0;
};