"""Single source for JobRunState reads/writes.

Mirrors ``settings_store``: ``record_finish`` never commits — the caller owns
the transaction — and reads are batched so the admin listing stays one query.
"""

from __future__ import annotations

import logging
from collections.abc import Iterable
from datetime import datetime, timezone

from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.models.job_run_state import JobRunState

logger = logging.getLogger(__name__)


def _as_datetime(value: object) -> datetime | None:
    """Runtime snapshots carry ISO strings; the column wants a datetime."""
    if isinstance(value, datetime):
        return value
    if isinstance(value, str) and value:
        try:
            return datetime.fromisoformat(value)
        except ValueError:
            return None
    return None


async def get_map(db: AsyncSession, job_names: Iterable[str]) -> dict[str, JobRunState]:
    """Return {job_name: row} for the given jobs that have ever finished."""
    result = await db.execute(
        select(JobRunState).where(JobRunState.job_name.in_(list(job_names)))
    )
    return {row.job_name: row for row in result.scalars().all()}


async def record_finish(db: AsyncSession, job_name: str, runtime: dict) -> JobRunState:
    """Upsert the last-run row from a scheduler runtime snapshot.

    Select-then-update-or-insert rather than a dialect-specific upsert, matching
    ``settings_store.upsert_setting`` — tests run on SQLite, prod on Postgres.
    """
    existing = await db.execute(
        select(JobRunState).where(JobRunState.job_name == job_name)
    )
    row = existing.scalar_one_or_none()

    finished_at = _as_datetime(runtime.get("finished_at")) or datetime.now(timezone.utc)
    status = str(runtime.get("status") or "completed")
    message = runtime.get("message")
    values = {
        "status": status,
        "started_at": _as_datetime(runtime.get("started_at")),
        "finished_at": finished_at,
        "processed": runtime.get("processed"),
        "total": runtime.get("total"),
        "message": str(message)[:4000] if message else None,
    }

    if row is None:
        row = JobRunState(job_name=job_name, **values)
        db.add(row)
    else:
        for field, value in values.items():
            setattr(row, field, value)
    return row