adding untracked files

controller/state/__init__.py

@@ -0,0 +1,19 @@
+
+
+def sync():
+    server = Server(API_BASE_URL, CONTROLLER_ID)
+    local = File(STATE_FILE)
+    server_state = server.get_state()
+
+    if local.present():
+        local.load()
+    else:
+        local.data = server_state
+        local.save()
+
+    local_state = local.data
+
+    changer = Changer(local_state, remote_state)
+    current_state = changer.process_change()
+
+    server.post_state(current_state)

controller/state/changer.py

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+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

controller/state/exceptions.py

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+
+class ClassNotReadyException(Exception):
+    def __init__(self, value):
+        self.value = value
+
+    def __str__(self):
+        return repr(self.value)
+
+class ErrorCommunicatingWithServerException(Exception):
+    def __init__(self, value):
+        self.value = value
+
+    def __str__(self):
+        return repr(self.value)

controller/state/file.py

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+import json
+import os.path
+
+
+
+class File(object):
+    "Holds controller state in the file"
+    def __init__(self, filename=None):
+        self.filename = filename
+
+    def present(self):
+        os.path.isfile(self.filename) 
+
+    def load(self):
+        if self.filename is None:
+            raise ClassNotReadyException("Filename not set!")
+        with open(self.filename) as input_file:
+            self.data = json.load(input_file)
+
+    def save(self):
+        if self.filename is None:
+            raise ClassNotReadyException("Filename not set!")
+        if self.data is None:
+            raise ClassNotReadyException("Data not loaded!")
+
+        with open(self.filename, 'w') as out_file:
+            json.dump(self.data, out_file)

controller/state/server.py

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+import json
+import requests
+
+
+class Server(object):
+    "Gets state from server and sends it to the server after change"
+    def __init__(self, url_base=None, controller_id=None):
+        self.url_base = url_base
+        self.controller_id = controller_id
+
+    def get_state(self):
+        result = requests.get(self.full_url('state/%s') % self.controller_id)
+        return handle_response(result)
+
+    def post_state(self, local_state):
+        result = requests.post(self.full_url('state/%s') % self.controller_id, local_state)
+        return handle_response(result)
+
+
+
+    def full_url(self, action):
+        if self.controller_id is None:
+            raise ClassNotReadyException("Controller id not set!")
+        if self.url_base is None:
+            raise ClassNotReadyException("URL base not set!")
+        return self.url_base + '/' + action
+
+
+def handle_response(response):
+    if response.status_code != 200:
+        raise ErrorCommunicatingWithServerException("Response not 200!")
+    else:
+        return response.json()