"""Base adapter interface for flight price sources."""

from abc import ABC, abstractmethod
from typing import Optional


class FlightAdapter(ABC):
    """Abstract base class for flight search adapters.

    All adapters must return a list of flight result dicts with keys:
        price_eur   (float)  - total round-trip price in EUR
        outbound_date (str)  - departure date YYYY-MM-DD
        return_date   (str)  - return date YYYY-MM-DD
        deep_link     (str)  - booking URL
        carrier       (str)  - airline name or IATA code
    """

    @abstractmethod
    def search(
        self,
        origin: str,
        destination: str,
        date_from: str,
        date_to: str,
        min_nights: int,
        max_nights: int,
    ) -> list[dict]:
        """Search for round-trip flights.

        Args:
            origin:      IATA airport/city code (e.g. "BER")
            destination: IATA airport/city code (e.g. "EZE")
            date_from:   Earliest outbound date, YYYY-MM-DD
            date_to:     Latest outbound date, YYYY-MM-DD
            min_nights:  Minimum stay duration
            max_nights:  Maximum stay duration

        Returns:
            List of result dicts (may be empty). Sorted by price ascending
            is preferred but not required.
        """
        ...