Overview This microservice allows users to store and retrieve ratings for artwork using ZeroMQ for communication. The ratings are saved in a JSON file (artwork_ratings.json) for persistence. The microservice can: 1. Store a rating for an artwork based on its ID. 2. Retrieve a rating for an artwork by its ID.

Prerequisites Python 3.x pyzmq Python Library(pip3 install pyzmq)

How to Use the Microservice Run the Microservice Start the microservice by running: python rating_service_zmq.py The service will bind to tcp://*:5555 and wait for requests.

Communication Contract The microservice communicates via JSON objects. The client must follow these structures to interact with the service.

1. Send a Rating
    To store a rating for an artwork, send a JSON object with the following structure:
    {
        "action": "rate",
        "artwork_id": "<ARTWORK_ID>",
        "rating": <RATING>
    }
    <ARTWORK_ID>: A unique identifier for the artwork (string or number).
    <RATING>: A value between 1 and 5 (inclusive).

Example Call (Python):
    socket.send_json({
        "action": "rate",
        "artwork_id": "123456",
        "rating": 4
    })
    response = socket.recv_json()
    print(response)  # Expected: {"message": "Rating recorded successfully."}

2. Retrieve a Rating
    To retrieve a rating for an artwork, send a JSON object with the following structure:
    {
        "action": "retrieve",
        "artwork_id": "<ARTWORK_ID>"
    }
    <ARTWORK_ID>: The unique identifier for the artwork whose rating is being retrieved.
    
Example Call (Python):
    socket.send_json({
        "action": "retrieve",
        "artwork_id": "123456"
    })
response = socket.recv_json()
print(response)  # Expected: {"artwork_id": "123456", "rating": 4}

Error Handling
If the artwork_id is not provided or invalid, the server responds with:
    {"error": "Invalid artwork ID or rating. Rating must be between 1 and 5."}

If no rating exists for the given artwork_id, the server responds with:
    {"error": "No rating found for artwork ID <ARTWORK_ID>"}

If an unsupported action is sent, the server responds with:
    {"error": "Invalid action"}