// SignalRouter: dispatches DSP hardware signals to handlers based on priority.

#pragma once

#include <cstdint>

#include <functional>

// Priority threshold for critical signal routing.

// Signals with priority strictly less than CRITICAL_THRESHOLD go to the critical handler.

// Signals with priority >= CRITICAL_THRESHOLD go to the standard event queue.

static constexpr uint8_t CRITICAL_THRESHOLD = 5;

struct Signal {

  uint8_t  priority; // signal urgency: 0 = highest urgency, 255 = lowest

  uint16_t sourceId; // hardware source channel identifier

  uint32_t payload;  // signal-specific data word

};

using HandlerFn = std::function<void(const Signal&)>;

// Routes incoming hardware signals to one of two registered handlers.

// Both handlers are invoked synchronously from route().

class SignalRouter {

public:

  // Parameters:

  //   onCritical - invoked for signals with priority < CRITICAL_THRESHOLD

  //   onStandard - invoked for signals with priority >= CRITICAL_THRESHOLD

  // Returns: new SignalRouter instance

  explicit SignalRouter(HandlerFn onCritical, HandlerFn onStandard);

  // Routes the signal to the appropriate handler based on its priority.

  // Parameters:

  //   sig - the hardware signal to dispatch

  // Returns: void

  void route(const Signal& sig);

  // Returns the cumulative number of signals routed since construction.

  uint32_t totalRouted() const { return totalRouted_; }

private:

  HandlerFn onCritical_; // handler for priority < CRITICAL_THRESHOLD

  HandlerFn onStandard_; // handler for priority >= CRITICAL_THRESHOLD

  uint32_t  totalRouted_ = 0; // cumulative count of all dispatched signals

};