import webiopi

GPIO = webiopi.GPIO

ICMP_DEVICE = "icmp0"
GAS_PORT = 0
SLEEP = 1

class State(object):
    def __init__(self, name, checks, expr, func):
        self.name    = name
        self.checks  = checks
        self.cnt     = 0
        self.enabled = True
        self.expr    = expr
        self.func    = func

    def incr(self, duration):
        if not self.expr(duration):
            self.cnt = 0
            return
        if self.cnt_reached():
            return
        self.cnt += 1
        if self.cnt_reached() and self.enabled:
            self.trigger()

    def trigger(self):
        webiopi.debug("GAS script - %s triggered" % (self.name))
        self.func()

    def cnt_reached(self):
        return self.cnt >= self.checks

    def __str__(self):
        enabled = "enabled" if self.enabled else "disabled"
        return "%s(%s) %d/%d" % (self.name, enabled, self.cnt,
            self.checks)

_online = State('Online',  5, lambda x: x > 0 and x < 300,
    lambda: GPIO.digitalWrite(GAS_PORT, GPIO.LOW))
_offline = State('Offline', 30, lambda x: not _online.expr(x),
    lambda: GPIO.digitalWrite(GAS_PORT, GPIO.HIGH))
STATES = [ _online, _offline ]

def setup():
    webiopi.debug("GAS script - setup")
    GPIO.setFunction(GAS_PORT, GPIO.OUT)
    GPIO.digitalWrite(GAS_PORT, GPIO.HIGH)

def loop():
    icmp = webiopi.deviceInstance(ICMP_DEVICE)
    if icmp is not None:
        duration = icmp.getMilliseconds()
        webiopi.debug("GAS script - %s: %dms" % (ICMP_DEVICE, duration))
        for s in STATES:
            s.incr(duration)
            webiopi.debug("GAS script - %s" % (s))
    webiopi.sleep(SLEEP)

def destroy():
    webiopi.debug("GAS script - destroy")
    GPIO.setFunction(GAS_PORT, GPIO.OUT)
    GPIO.digitalWrite(GAS_PORT, GPIO.HIGH)

@webiopi.macro
def gas_getPort():
    global GAS_PORT
    return str(GAS_PORT)

_force = None

@webiopi.macro
def gas_getForce():
    global _force
    if _force is None:
        return ""
    return _force.name

@webiopi.macro
def gas_setForce(state = None):
    global _force
    webiopi.debug("GAS script - forcing state %s" % (state))

    if state is None:
        _force = None
        for s in STATES:
            s.enabled = True
            # trigger again if mode is automatic
            if s.cnt_reached():
                s.trigger()
    else:
        for s in STATES:
            if s.name == state:
                _force = s
                break
        if _force is not None:
            for s in STATES:
                s.enabled = False
            _force.trigger()

    return gas_getForce()