from datetime import date, timedelta
from decimal import Decimal
from flask import current_app
from .http import get_json

PRODUCT_IDS = {"PB95": 41, "PB98": 42, "DIESEL": 43}
POLISH_REGIONS = (
    "dolnośląskie", "kujawsko-pomorskie", "lubelskie", "lubuskie", "łódzkie",
    "małopolskie", "mazowieckie", "opolskie", "podkarpackie", "podlaskie",
    "pomorskie", "śląskie", "świętokrzyskie", "warmińsko-mazurskie",
    "wielkopolskie", "zachodnio-pomorskie",
)


def _rows(url, params=None):
    data = get_json(url, params=params, timeout_key="ORLEN_TIMEOUT_SECONDS")
    if not isinstance(data, list):
        raise ValueError("Nieprawidłowa odpowiedź API Orlen")
    return data


def fetch_orlen_range(fuel_type, date_from, date_to, region="mazowieckie"):
    fuel_type = fuel_type.upper()
    if fuel_type == "LPG":
        result, seen = [], set()
        current = date_from
        while current <= date_to:
            rows = _rows(current_app.config["ORLEN_LPG_BY_DATE_URL"], {"date": current.isoformat()})
            for row in rows:
                row_region = (row.get("locationName") or "").strip().lower()
                if region and str(region).lower() not in ("all", "*") and row_region != str(region).lower():
                    continue
                effective = date.fromisoformat(row["effectiveDate"][:10])
                if not (date_from <= effective <= date_to):
                    continue
                key = (effective, row_region)
                if key in seen:
                    continue
                seen.add(key)
                value = Decimal(str(row["value"]))
                result.append({"fuel_type": "LPG", "effective_date": effective, "price_per_liter": value,
                    "raw_value": value, "region": row_region, "product_name": row.get("productName") or "LPG",
                    "source": f"Orlen LPG ByDate, {row_region}"})
            current += timedelta(days=1)
        return result

    product_id = PRODUCT_IDS.get(fuel_type)
    if not product_id:
        raise ValueError("Nieobsługiwany rodzaj paliwa")
    rows = _rows(current_app.config["ORLEN_WHOLESALE_URL"], {
        "productId": product_id, "from": date_from.isoformat(), "to": date_to.isoformat()
    })
    result = []
    for row in rows:
        effective = date.fromisoformat(row["effectiveDate"][:10])
        raw = Decimal(str(row["value"]))
        result.append({"fuel_type": fuel_type, "effective_date": effective, "price_per_liter": raw / Decimal("1000"),
            "raw_value": raw, "region": "", "product_name": row.get("productName") or fuel_type,
            "source": f"Orlen {row.get('productName') or fuel_type}, netto/m³ → zł/l"})
    return result


def fetch_orlen_price(fuel_type, day=None, region="mazowieckie"):
    day = day or date.today()
    rows = fetch_orlen_range(fuel_type, day.replace(day=1), day, region)
    candidates = [row for row in rows if row["effective_date"] <= day]
    if not candidates:
        raise ValueError("Brak ceny Orlen dla wybranej daty")
    row = max(candidates, key=lambda item: item["effective_date"])
    return {"price_per_liter": float(row["price_per_liter"]), "date": row["effective_date"].isoformat(), "source": row["source"]}