"""Helpers for publishing invalid messages to the DLQ."""

from typing import Sequence

from confluent_kafka.serialization import StringSerializer
from kafka_utils.producer.event import EventProducer
from lambdacommon.common_config import logger
import config
from src.models.preference_change import InvalidPreferenceMessage


def send_invalid_messages(messages: Sequence[InvalidPreferenceMessage]) -> None:
    """Send invalid preference change messages to the configured DLQ topic."""
    if not messages:
        return

    logger.info(f'Sending {len(messages)} invalid message(s) to DLQ topic {config.settings.kafka_dlq_topic}')
    event_producer_params = dict(
        bootstrap_servers=config.settings.kafka_bootstrap_servers,
        key_serializer=StringSerializer(),
        value_serializer=StringSerializer(),
        security_protocol=config.settings.kafka_security_protocol
    )

    with EventProducer(**event_producer_params) as producer:
        for message in messages:
            headers = {
                'errorType': message.error_type.encode(),
                'errorMessage': message.error_message.encode(),
            }
            producer.produce(
                topic=config.settings.kafka_dlq_topic,
                event_key=message.message_key,
                event_value=message.message_value,
                headers=headers,
                auto_flush=False,
            )