FSM.hh

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#ifndef COSA_FSM_HH
#define COSA_FSM_HH

#include "Cosa/Job.hh"
#include "Cosa/Event.hh"
#include "Cosa/Watchdog.hh"

class FSM : protected Job {
public:
  typedef bool (*StateHandler)(FSM* fsm, uint8_t type);

  FSM(StateHandler init, Job::Scheduler* scheduler = NULL, uint16_t period = 0) :
    Job(scheduler),
    m_state(init),
    m_period(period),
    m_param(0)
  {}

  void state(StateHandler fn)
    __attribute__((always_inline))
  {
    if (UNLIKELY(fn == NULL)) return;
    m_state = fn;
  }

  StateHandler state() const
    __attribute__((always_inline))
  {
    return (m_state);
  }

  void period(uint8_t ms)
  {
    m_period = ms;
  }

  void get(uint16_t& param) const
  {
    param = m_param;
  }

  void get(void*& param) const
  {
    param = (void*) m_param;
  }

  void send(uint8_t type, uint16_t value = 0)
    __attribute__((always_inline))
  {
    Event::push(type, this, value);
  }

  void send(uint8_t type, void* value)
    __attribute__((always_inline))
  {
    Event::push(type, this, value);
  }

  bool begin()
  {
    if ((m_period != 0) && (m_period != TIMEOUT_REQUEST)) {
      expire_after(m_period);
      start();
    }
    send(Event::BEGIN_TYPE);
    return (true);
  }

  void end()
  {
    cancel_timer();
    send(Event::END_TYPE);
  }

  void set_timer(uint16_t ms)
    __attribute__((always_inline))
  {
    m_period = TIMEOUT_REQUEST;
    expire_after(ms);
    start();
  }

  void cancel_timer()
    __attribute__((always_inline))
  {
    if (UNLIKELY(m_period == 0)) return;
    stop();
    m_period = 0;
  }

private:
  static const uint16_t TIMEOUT_REQUEST = 0xffff;
  StateHandler m_state;
  uint16_t m_period;
  uint16_t m_param;

  virtual void on_event(uint8_t type, uint16_t value)
  {
    m_param = value;
    m_state(this, type);
    if (type == Event::TIMEOUT_TYPE) {
      if ((m_period != 0) && (m_period != TIMEOUT_REQUEST)) {
        expire_after(m_period);
        start();
      }
    }
  }
};

#endif