import structlog

logger = structlog.get_logger()

PAIRS = [
    ("GBP", "USD"), ("GBP", "EUR"), ("GBP", "JPY"), ("GBP", "CAD"),
    ("GBP", "AUD"), ("GBP", "CHF"), ("USD", "GBP"), ("EUR", "GBP"),
]


async def fx_sync_job() -> None:
    from app.dependencies import get_session_factory
    session_factory = get_session_factory()
    if not session_factory:
        return

    try:
        import requests
        r = requests.get(
            "https://api.exchangerate-api.com/v4/latest/GBP",
            timeout=10,
        )
        r.raise_for_status()
        data = r.json()
        rates = data.get("rates", {})
    except Exception as exc:
        logger.error("fx_fetch_failed", error=str(exc))
        return

    from datetime import datetime, timezone
    from decimal import Decimal
    import uuid as _uuid
    from sqlalchemy import select
    from app.db.models.currency import ExchangeRate  # type: ignore[attr-defined]

    async with session_factory() as db:
        try:
            now = datetime.now(timezone.utc)
            for base, quote in PAIRS:
                if base == "GBP":
                    rate_val = rates.get(quote)
                else:
                    gbp_to_base = rates.get(base)
                    if not gbp_to_base or gbp_to_base == 0:
                        continue
                    rate_val = 1 / gbp_to_base

                if not rate_val:
                    continue

                result = await db.execute(
                    select(ExchangeRate).where(
                        ExchangeRate.base_currency == base,
                        ExchangeRate.quote_currency == quote,
                    )
                )
                existing = result.scalar_one_or_none()
                if existing:
                    existing.rate = Decimal(str(round(rate_val, 8)))
                    existing.fetched_at = now
                else:
                    db.add(ExchangeRate(
                        id=_uuid.uuid4(),
                        base_currency=base,
                        quote_currency=quote,
                        rate=Decimal(str(round(rate_val, 8))),
                        source="exchangerate-api",
                        fetched_at=now,
                    ))
            await db.commit()
            logger.info("fx_sync_done", pairs=len(PAIRS))
        except Exception as exc:
            await db.rollback()
            logger.error("fx_sync_db_failed", error=str(exc))