import functools


def Debounce(threshold=100):
    """
    Simple debouncing decorator for apigpio callbacks.

    Example:

    `@Debouncer()
     def my_cb(gpio, level, tick)
         print('gpio cb: {} {} {}'.format(gpio, level, tick))
    `

    The threshold can be given to the decorator as an argument (in millisec).
    This decorator can be used both on function and object's methods.

    Warning: as the debouncer uses the tick from pigpio, which wraps around
    after approximately 1 hour 12 minutes, you could theoretically miss one
    call if your callback is called twice with that interval.
    """
    threshold *= 1000

    class _decorated(object):

        def __init__(self, pigpio_cb):
            self._fn = pigpio_cb
            self.last = 0
            self.is_method = False

        def __call__(self, *args, **kwargs):
            if self.is_method:
                tick = args[3]
            else:
                tick = args[2]
            if tick - self.last > threshold:
                self._fn(*args, **kwargs)
                self.last = tick

        def __get__(self, instance, type=None):
            # with is called when an instance of `_decorated` is used as a class
            # attribute, which is the case when decorating a method in a class
            self.is_method = True
            return functools.partial(self, instance)

    return _decorated

import functools


def Debounce(threshold=100):
    """
    Simple debouncing decorator for apigpio callbacks.

    Example:

    `@Debouncer()
     def my_cb(gpio, level, tick)
         print('gpio cb: {} {} {}'.format(gpio, level, tick))
    `

    The threshold can be given to the decorator as an argument (in millisec).
    This decorator can be used both on function and object's methods.

    Warning: as the debouncer uses the tick from pigpio, which wraps around
    after approximately 1 hour 12 minutes, you could theoretically miss one
    call if your callback is called twice with that interval.
    """
    threshold *= 1000
    max_tick = 0xFFFFFFFF

    class _decorated(object):

        def __init__(self, pigpio_cb):
            self._fn = pigpio_cb
            self.last = 0
            self.is_method = False

        def __call__(self, *args, **kwargs):
            if self.is_method:
                tick = args[3]
            else:
                tick = args[2]
            if self.last > tick:
                delay = max_tick-self.last + tick
            else:
                delay = tick - self.last
            if delay > threshold:
                self._fn(*args, **kwargs)
                print('call passed by debouncer {} {} {}'
                      .format(tick, self.last, threshold))
                self.last = tick
            else:
                print('call filtered out by debouncer {} {} {}'
                      .format(tick, self.last, threshold))

        def __get__(self, instance, type=None):
            # with is called when an instance of `_decorated` is used as a class
            # attribute, which is the case when decorating a method in a class
            self.is_method = True
            return functools.partial(self, instance)

    return _decorated

Fix callback erroneously filtered out
Fix callback erroneously filtered out

The tick from pigpio wraps aroud after xFFFFFFFF,
approximately 1h13. When it wraps the delay was not computed
correctly, causing all following calls to be filtered out.
