import device



# This class is a dispatcher. It will send the MIDI event to the appropriate fonction

# MIDI event dispatcher transforms the MIDI event into a value through a transform function provided at construction
# time. This value is then used as a key into a lookup table that provides a dispatcher and filter function. If the
# filter function returns true, then the event is sent to the dispatcher function.

class MidiEventDispatcher:


    def __init__(self, transform_fn):
        self._transform_fn = transform_fn
        # Table contains a mapping of status code -> (callback_fn, filter_fn)
        self._dispatch_map = {}


    def NewHandler(self, key, callback_fn, filter_fn =None):
        #This function will create a new like between a key and a function

        # param key: the result value of transform_fn(event) to match against.
        # param callback_fn: function that is called with the event in the event the transformed event matches.
        # param filter_fn: function that takes an event and returns true if the event should be dispatched. If false
        # is returned, then the event is dropped and never passed to callback_fn. Not specifying means that callback_fn
        # is always called if transform_fn matches the key.

        
        def _default_true_fn(_): return True
        if filter_fn is None:
            filter_fn = _default_true_fn
        self._dispatch_map[key] = (callback_fn, filter_fn)
        return self


    def NewHandlerForKeys(self, keys, callback_fn, filter_fn=None):
        
        # Same function but for a group of controls
        
        for k in keys:
            self.NewHandler(k, callback_fn, filter_fn=filter_fn)
        return self


    def Dispatch(self, event):
        # This function will dispatch the event
    
        key = self._transform_fn(event)
        processed = False
        if key in self._dispatch_map:
            callback_fn, filter_fn = self._dispatch_map[key]
            if filter_fn(event):
                callback_fn(event)
                processed = True
            else:
                processed = True
        return processed



def send_to_device(data) :
    #The only function that will sens SysEx data to the controller
    device.midiOutSysex(bytes([0xF0, 0x00, 0x20, 0x6B, 0x7F, 0x42]) + data + bytes([0xF7]))