import json

from smelog.factory import BoundLogger

from juno_filters_messages.clients import service
from juno_filters_messages.constants import DATA_FIELDS, TTL


def parse_events(lambda_event: dict) -> list:
    result = []
    for record in lambda_event.get("Records", []):
        body = json.loads(record["body"])
        event = json.loads(body.get("Message", {}))
        if event:
            result.append(event)
    return result


def handler(logger: BoundLogger, lambda_event: dict):
    """Lambda job.

    Args:
        logger: Logger instance.
        lambda_event: Lambda event obj.

    Returns:
        JSON serializable response

    """

    event_list = parse_events(lambda_event)

    if event_list:
        settings_list = service.user_data.get_settings()
    else:
        settings_list = []

    for event in event_list:
        event_id = event["id"]

        sent_message_list = [
            (i["account_id"], i["meta"]["filter_id"])
            for i in service.user_data.get_messages(event_id)
        ]

        logger.debug(f"{event_id}: {len(sent_message_list)} messages found")

        new_message_list = []
        for settings in settings_list:
            user_id, account_id, settings_id, filter_map = (
                settings["user_id"],
                settings["account_id"],
                settings["settings"]["id"],
                settings["settings"]["data"].get("juno_filters", {}).get("filters", {}),
            )
            for filter_id, filter_data in filter_map.items():
                if not filter_data.get("is_subscribed") or (account_id, filter_id) in sent_message_list:
                    continue

                new_message_list.append(
                    {
                        "ttl": TTL,
                        "event_id": event_id,
                        "account_id": account_id,
                        "meta": {
                            "subject": "juno_digest",
                            "views": ["juno_email"],
                            "user_id": user_id,
                            "settings_id": settings_id,
                            "filter_id": filter_id,
                        },
                        "data": {
                            key: value for key, value in filter_data.items() if key in DATA_FIELDS
                        },
                    }
                )

        logger.debug(f"{len(new_message_list)} messages to send")
        if new_message_list:
            service.user_data.post_messages(data=new_message_list)