adding untracked files

controller/state/changer.py

@@ -0,0 +1,39 @@
+import RPi.GPIO as GPIO
+import config
+
+class Changer(object):
+
+    def __init__(self, local_state, remote_state):
+        self.local_state = local_state
+        self.remote_state = remote_state
+        GPIO.setmode(GPIO.BCM) # Broadcom pin-numbering scheme
+        GPIO.setup(GPIO_PIN_VALVE, GPIO.OUT)
+
+        self.states = {
+          'opening': self.open_valve,
+          'closing': self.close_valve,
+          'open': self.open_valve,
+          'closed': self.close_valve
+
+        }
+
+    def process_change(self):
+        self.validate_states()
+        if self.local_state['out_valve'] != self.remote_state['out_valve']:
+            change = self.states.get(self.remote_state['out_valve'], None )
+            if change is not None:
+                change()
+        return self.local_state
+
+    def open_valve():
+        GPIO.output(GPIO_PIN_VALVE, GPIO.HIGH)
+        self.local_state['out_valve'] = 'open'
+
+    def close_valve():
+        GPIO.output(GPIO_PIN_VALVE, GPIO.LOW)
+        self.local_state['out_valve'] = 'closed'
+
+    def validate_states(self):
+        if self.local_state is None or self.remote_state is None:
+            raise ClassNotReadyException("Both local and remote states must be present!")
+        # TODO: add detailed validation