"""In-process job dispatch. SQS when JOBS_QUEUE_URL is set; otherwise run inline."""

from __future__ import annotations

import importlib.util
import json
import logging
import os
import sys
from pathlib import Path

import boto3

from shared.holiday_flow import activate, deactivate
from shared.schedule import ShiftSchedule

logger = logging.getLogger(__name__)

_SRC = Path(__file__).resolve().parents[1]
_sqs = None
_handlers: dict[str, object] = {}


def _client():
    global _sqs
    if _sqs is None:
        _sqs = boto3.client("sqs")
    return _sqs


def _load_lambda_app(dirname: str):
    if dirname in _handlers:
        return _handlers[dirname]
    path = _SRC / dirname / "app.py"
    name = f"afterhours_{dirname.replace('-', '_')}"
    spec = importlib.util.spec_from_file_location(name, path)
    if spec is None or spec.loader is None:
        raise ImportError(f"cannot load {path}")
    mod = importlib.util.module_from_spec(spec)
    sys.modules[name] = mod
    spec.loader.exec_module(mod)
    _handlers[dirname] = mod
    return mod


def enqueue_job(payload: dict) -> None:
    queue_url = os.environ.get("JOBS_QUEUE_URL", "").strip()
    body = json.dumps(payload, default=str)
    if not queue_url:
        run_job(payload)
        return
    _client().send_message(QueueUrl=queue_url, MessageBody=body)


def _run_holiday(payload: dict) -> dict:
    action = payload.get("action")
    date = payload.get("date")
    if not date:
        return {"error": True, "reason": "missing_date"}
    schedule = ShiftSchedule()
    if action == "activate":
        return activate(schedule, date)
    if action == "deactivate":
        return deactivate(schedule, date)
    return {"error": True, "reason": "unknown_action", "action": action}


def run_job(payload: dict) -> dict:
    event_type = payload.get("event", "")
    if event_type == "holiday":
        return _run_holiday(payload)
    forced = {**payload, "force": True}
    if event_type == "weekly_post":
        return _load_lambda_app("weekly-post").handler(forced, None)
    if event_type == "roster_sync":
        return _load_lambda_app("roster-sync").handler(forced, None)
    if event_type in {"ring_scheduler_daily", "ring_scheduler_weekend"}:
        return _load_lambda_app("ring-scheduler").handler(forced, None)
    raise ValueError(f"unknown job event {event_type!r}")