from datetime import datetime

import httpx
from sqlalchemy import and_, select
from sqlalchemy.orm import Session

from ..models import PriceSnapshot, Product, ScrapeRun, Store

AH_AUTH_URL = "https://api.ah.nl/mobile-auth/v1/auth/token/anonymous"
AH_SEARCH_URL = "https://api.ah.nl/mobile-services/product/search/v2"
AH_BASE_URL = "https://www.ah.nl"
AH_CLIENT_ID = "appie"


def _get_token(client: httpx.Client) -> str:
    resp = client.post(AH_AUTH_URL, json={"clientId": AH_CLIENT_ID})
    resp.raise_for_status()
    return resp.json()["access_token"]


def _search(client: httpx.Client, token: str, query: str, page: int = 0, size: int = 30) -> dict:
    resp = client.get(
        AH_SEARCH_URL,
        params={"query": query, "page": page, "size": size},
        headers={"Authorization": f"Bearer {token}"},
    )
    resp.raise_for_status()
    return resp.json()


def _to_cents(value: float | int | None) -> int | None:
    if value is None:
        return None
    return round(float(value) * 100)


def _upsert_store(db: Session) -> Store:
    store = db.scalar(select(Store).where(Store.slug == "albert-heijn"))
    if not store:
        store = Store(
            name="Albert Heijn",
            slug="albert-heijn",
            country="NL",
            website="https://www.ah.nl",
        )
        db.add(store)
        db.commit()
        db.refresh(store)
    return store


def scrape_query(db: Session, query: str) -> ScrapeRun:
    store = _upsert_store(db)

    run = ScrapeRun(store_id=store.id, query=query, started_at=datetime.utcnow())
    db.add(run)
    db.commit()
    db.refresh(run)

    try:
        with httpx.Client(timeout=30.0) as client:
            token = _get_token(client)
            data = _search(client, token, query)

        count = 0
        now = datetime.utcnow()

        for card in data.get("cards", []):
            for raw in card.get("products", []):
                external_id = str(raw.get("webshopId", "")).strip()
                if not external_id:
                    continue

                product = db.scalar(
                    select(Product).where(
                        and_(
                            Product.store_id == store.id,
                            Product.external_id == external_id,
                        )
                    )
                )
                if not product:
                    product = Product(store_id=store.id, external_id=external_id)
                    db.add(product)

                link = raw.get("link", "") or ""
                product.name = raw.get("title", "") or ""
                product.brand = raw.get("brand") or None
                product.category = raw.get("category") or None
                product.ean = raw.get("eanCode") or None
                product.url = f"{AH_BASE_URL}{link}" if link else None
                product.updated_at = now

                price_info = raw.get("price") or {}
                price_cents = _to_cents(price_info.get("now"))
                was_cents = _to_cents(price_info.get("was"))

                unit_info = price_info.get("unitInfo") or {}
                unit_price_cents = _to_cents(unit_info.get("price"))
                unit_description = unit_info.get("description") or None

                discount = raw.get("discount") or {}
                discount_label = discount.get("label") or None
                discount_description = discount.get("description") or None

                db.flush()  # get product.id if newly created

                if price_cents is not None:
                    snapshot = PriceSnapshot(
                        product_id=product.id,
                        scrape_run_id=run.id,
                        price=price_cents,
                        unit_price=unit_price_cents,
                        unit_description=unit_description,
                        was_price=was_cents,
                        is_on_sale=was_cents is not None or discount_label is not None,
                        discount_label=discount_label,
                        discount_description=discount_description,
                        timestamp=now,
                    )
                    db.add(snapshot)
                    count += 1

        db.commit()
        run.status = "success"
        run.products_found = count
        run.finished_at = datetime.utcnow()
        db.commit()

    except Exception as exc:
        db.rollback()
        run.status = "failed"
        run.error_message = str(exc)[:900]
        run.finished_at = datetime.utcnow()
        db.commit()
        raise

    return run