"""
Contains the parent class all mods should inherit from, and some utility
functions mods will need to use.
"""


def pysweep_listen(mod, trigger):
    """
    Decorator for methods that need to be callable by other mods.
    """
    def decorate(f):
        try:
            f.pysweep_listening_to
        except:
            f.pysweep_listening_to = []
        f.pysweep_listening_to.append((mod, trigger))
        return f
    return decorate

def pysweep_trigger(f):
    """
    Decorator for methods that need to trigger mods listening to this event.

    The method should return an event object which is passed to the mods
    listening to this function.
    """
    def _wrap(self, *args, **kwargs):
        event = f(_wrap)
        listener_events = []
        for listener in f.pysweep_listened_by:
            listener_events = listener(event)
        event.children = listener_events
        return event
    _wrap.pysweep_is_trigger = True
    return _wrap

class Mod:
    def pysweep_init(self, pysweep):
        self.pysweep = pysweep

    def pysweep_triggers_init(self):
        self.triggers = []
        for func in self.__dict__.values():
            try:
                func.pysweep_is_trigger
            except:
                func.pysweep_is_trigger = False

            if func.pysweep_is_trigger:
                self.triggers.append(func)
                self.trigger.pysweep_listened_by = []

    def pysweep_listeners_init(self):
        for func in self.__dict__.values():
            try:
                func.pysweep_listening_to
            except:
                func.pysweep_listening_to = []

            for mod, trigger in func.pysweep_listening_to:
                self.pysweep.mods[mod].pysweep_register(trigger, func)

    def pysweep_register(self, trigger, func):
        try:
            self.trigger
        except:
            raise ValueError("Trigger {} does not exist".format(trigger))

        if not self.trigger.pysweep_is_trigger:
            raise ValueError("{} is not a trigger".format(trigger))

        self.trigger.pysweep_listened_by.append(func)