"""Exact lookups: Komm-Nr, DVN, VIN.

Loco-Soft Komm-Nr-Schema:
  Type-Buchstabe (N/T/V/D/G/L) + DVN-Zahl (4-6 Stellen)
  Beispiele: 'D9094' (Nissan Leaf), 'N8093' (Askoll XKP45), 'L9083' (Opel)

  N = Neu, T = Tageszul., V = Vorfuehr,
  D = Differenzbest., G = Gebraucht, L = Leihgabe

DVN allein ist eindeutig pro Fahrzeug, deshalb auch als Such-Einstieg möglich.
"""
import re

from app import db
from app.schemas import SearchResultItem


COLUMNS = """
    vehicle_id, dvn, commission_number, vin, brand, model, title,
    price::float8 as price, primary_image_id::text as primary_image_id,
    directus_product_id, dealer_vehicle_type
"""

KOMM_NR_RE = re.compile(r"^([NTVDGLntvdgl])\s*(\d{4,6})$")


def normalize_komm_nr(raw: str) -> str | None:
    """'D 9094' / 'd9094' / ' D9094 ' -> 'D9094'. Returns None if not a valid pattern."""
    if not raw:
        return None
    m = KOMM_NR_RE.match(raw.strip())
    if not m:
        return None
    return m.group(1).upper() + m.group(2)


async def by_komm_nr(raw: str) -> list[SearchResultItem]:
    """Lookup by full Komm-Nr (Type-Letter + DVN). Eindeutig wenn vorhanden."""
    normalized = normalize_komm_nr(raw)
    if not normalized:
        return []
    sql = f"SELECT {COLUMNS} FROM search_vehicles WHERE commission_number = $1 LIMIT 5"
    rows = await db.fetch(sql, normalized)
    return [_row_to_item(r, matched_via="exact_komm") for r in rows]


async def by_dvn(number: str) -> list[SearchResultItem]:
    """Lookup by DVN allein (4-6 stellige Zahl ohne Type-Buchstabe).
    DVN ist eindeutig pro Fahrzeug, also liefert das immer 0 oder 1 Treffer."""
    try:
        dvn_int = int(number)
    except (ValueError, TypeError):
        return []
    sql = f"SELECT {COLUMNS} FROM search_vehicles WHERE dvn = $1 LIMIT 5"
    rows = await db.fetch(sql, dvn_int)
    return [_row_to_item(r, matched_via="exact_dvn") for r in rows]


async def by_vin(vin: str) -> list[SearchResultItem]:
    sql = f"SELECT {COLUMNS} FROM search_vehicles WHERE vin = $1 LIMIT 5"
    rows = await db.fetch(sql, vin)
    return [_row_to_item(r, matched_via="exact_vin") for r in rows]


def _row_to_item(row, matched_via: str) -> SearchResultItem:
    return SearchResultItem(
        vehicle_id=row["vehicle_id"],
        commission_number=row["commission_number"],
        vin=row["vin"],
        brand=row["brand"],
        model=row["model"],
        title=row["title"] or "",
        price=row["price"],
        primary_image_id=row["primary_image_id"],
        directus_product_id=row["directus_product_id"],
        score=1.0,
        matched_via=matched_via,
    )