sequenceDiagram
    participant Z as Zenoh
    participant MLS as McapLoggerService
    participant MW as McapWriter

    MLS ->> Z: Subscribe to key_expr
    %% Message processing loop begins after subscription
    Z ->> MLS: zenoh.Sample (message)
    MLS ->> MLS: Parse JSON payload from sample
    MLS ->> MLS: Validate parsed data
    alt Data is valid and parsed
        alt Topic's schema not yet in schema_map
            alt Topic name ends with "/log" (Foxglove Log)
                MLS ->> MW: register_schema(name="foxglove.Log", encoding="jsonschema", data=JSON_Log_Schema)
                MW -->> MLS: schema_id
                MLS ->> MW: register_channel(schema_id, topic, message_encoding="json")
                MW -->> MLS: channel_id
                MLS ->> MLS: Store schema_id in schema_map
                MLS ->> MLS: Store channel_id in channel_map
            else Regular Topic
                MLS ->> MLS: create_schema(data) (using genson)
                MW -->> MLS: schema_data (JSON bytes)
                MLS ->> MW: register_schema(name=json_topic_name, encoding="jsonschema", data=schema_data)
                MW -->> MLS: schema_id
                MLS ->> MLS: Store schema_id in schema_map
            end
        end

        alt Topic's channel not yet in channel_map AND not a Foxglove Log topic (whose channel was just registered)
            MLS ->> MLS: Get schema_id from schema_map (for regular topic)
            MLS ->> MW: register_channel(schema_id, topic, message_encoding="json")
            MW -->> MLS: channel_id
            MLS ->> MLS: Store channel_id in channel_map
        end

        MLS ->> MLS: Get channel_id from channel_map (guaranteed to be present now)
        MLS ->> MLS: Get current timestamp (ts_ns)
        MLS ->> MW: add_message(channel_id, log_time=ts_ns, publish_time=ts_ns, data=json.dumps(data).encode())
    else Data is invalid or parsing failed
        MLS ->> MLS: Log error/warning and skip message
    end