| 1 | import asyncio |
| 2 | import logging |
| 3 | from datetime import datetime, timezone |
| 4 | from typing import Sequence |
| 5 | |
| 6 | import ocpp.v201 |
| 7 | import websockets |
| 8 | from ocpp.routing import on |
| 9 | from ocpp.v201 import call_result |
| 10 | from ocpp.v201.enums import RegistrationStatusType, ClearCacheStatusType |
| 11 | |
| 12 | # Setting up the logging configuration to display debug level messages. |
| 13 | logging.basicConfig(level=logging.DEBUG) |
| 14 | |
| 15 | |
| 16 | # Define a ChargePoint class inheriting from the OCPP 2.0.1 ChargePoint class. |
| 17 | class ChargePoint(ocpp.v201.ChargePoint): |
| 18 | # Message handlers to receive OCPP message. |
| 19 | @on('BootNotification') |
| 20 | async def on_boot_notification(self, charging_station, reason, **kwargs): |
| 21 | logging.info("Received BootNotification") |
| 22 | # Create and return a BootNotification response with the current time, |
| 23 | # an interval of 10 seconds, and an accepted status. |
| 24 | return call_result.BootNotification( |
| 25 | current_time=datetime.now(timezone.utc).isoformat(), |
| 26 | interval=10, |
| 27 | status=RegistrationStatusType.accepted |
| 28 | ) |
| 29 | |
| 30 | # Request handlers to emit OCPP messages. |
| 31 | async def send_clear_cache(self): |
| 32 | request = ocpp.v201.call.ClearCache() |
| 33 | response = await self.call(request) |
| 34 | |
| 35 | if response.status == ClearCacheStatusType.accepted: |
| 36 | logging.info("Cache cleared successfully") |
| 37 | else: |
| 38 | logging.info("Cache clearing failed") |
| 39 | |
| 40 | |
| 41 | # Function to handle new WebSocket connections. |
| 42 | async def on_connect(websocket, path): |
| 43 | """ For every new charge point that connects, create a ChargePoint instance and start |
| 44 | listening for messages.""" |
| 45 | try: |
| 46 | requested_protocols = websocket.request_headers['Sec-WebSocket-Protocol'] |
| 47 | except KeyError: |
| 48 | logging.info("Client hasn't requested any Subprotocol. Closing Connection") |
| 49 | return await websocket.close() |
| 50 | |
| 51 | if websocket.subprotocol: |
| 52 | logging.info("Protocols Matched: %s", websocket.subprotocol) |
| 53 | else: |
| 54 | logging.warning('Protocols Mismatched | Expected Subprotocols: %s,' |
| 55 | ' but client supports %s | Closing connection', |
| 56 | websocket.available_subprotocols, |
| 57 | requested_protocols) |
| 58 | return await websocket.close() |
| 59 | |
| 60 | charge_point_id = path.strip('/') |
| 61 | cp = ChargePoint(charge_point_id, websocket) |
| 62 | |
| 63 | # Start the ChargePoint instance to listen for incoming messages. |
| 64 | await cp.start() |
| 65 | |
| 66 | |
| 67 | # Main function to start the WebSocket server. |
| 68 | async def main(): |
| 69 | # Create the WebSocket server and specify the handler for new connections. |
| 70 | server = await websockets.serve( |
| 71 | on_connect, |
| 72 | '127.0.0.1', # Listen on loopback. |
| 73 | 9000, # Port number. |
| 74 | subprotocols=Sequence['ocpp2.0', 'ocpp2.0.1'] # Specify OCPP 2.0.1 subprotocols. |
| 75 | ) |
| 76 | logging.info("WebSocket Server Started") |
| 77 | # Wait for the server to close (runs indefinitely). |
| 78 | await server.wait_closed() |
| 79 | |
| 80 | |
| 81 | # Entry point of the script. |
| 82 | if __name__ == '__main__': |
| 83 | # Run the main function to start the server. |
| 84 | asyncio.run(main()) |