import json
import os
from datetime import datetime
from zoneinfo import ZoneInfo

import boto3

from shared.db import current_week, get_form_status, set_form_status

_lambda = boto3.client("lambda")
EASTERN = ZoneInfo("America/New_York")


def lambda_handler(event, context):
    now_et = datetime.now(EASTERN)
    # EventBridge can fire slightly after midnight ET; accept Thu 23:xx or Fri 00–03
    # ET so a delayed cron still closes the form. Idempotency: already-closed is a no-op.
    in_close_window = (now_et.weekday() == 3 and now_et.hour == 23) or (
        now_et.weekday() == 4 and now_et.hour < 4
    )
    if not in_close_window:
        return {
            "status": "skipped",
            "reason": "outside close window (must be Thu 23:xx or Fri 00–03 ET)",
        }

    week = event.get("week", current_week())

    status = get_form_status(week)
    if status == "closed":
        return {"status": "already_closed", "week": week}

    set_form_status(week, "closed")

    _lambda.invoke(
        FunctionName=os.environ["AGGREGATE_FUNCTION_ARN"],
        InvocationType="Event",
        Payload=json.dumps({"week": week}),
    )

    return {"status": "closed", "week": week, "aggregate_triggered": True}