"""Kiwi/Tequila flight search adapter.

Requires a free API key from https://tequila.kiwi.com/
Set it via the KIWI_API_KEY environment variable.

Without a key this adapter acts as a stub: it logs instructions and returns
an empty list so the rest of the monitor pipeline still runs cleanly.
"""

import logging
import os
from datetime import datetime

import requests

from .base import FlightAdapter

logger = logging.getLogger(__name__)

KIWI_API_URL = "https://api.tequila.kiwi.com/v2/search"


class KiwiAdapter(FlightAdapter):
    """Adapter for the Kiwi/Tequila v2 flight search API."""

    def __init__(self):
        self.api_key = os.environ.get("KIWI_API_KEY", "").strip()

    # ------------------------------------------------------------------
    # Public interface
    # ------------------------------------------------------------------

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

        Returns an empty list (with a log warning) when no API key is set.
        """
        if not self.api_key:
            logger.warning(
                "Kiwi adapter requires API key — set KIWI_API_KEY env var. "
                "Get a free key at https://tequila.kiwi.com/"
            )
            return []

        return self._fetch(
            origin=origin,
            destination=destination,
            date_from=date_from,
            date_to=date_to,
            min_nights=min_nights,
            max_nights=max_nights,
        )

    # ------------------------------------------------------------------
    # Internal
    # ------------------------------------------------------------------

    def _fetch(
        self,
        origin: str,
        destination: str,
        date_from: str,
        date_to: str,
        min_nights: int,
        max_nights: int,
    ) -> list[dict]:
        params = {
            "fly_from": origin,
            "fly_to": destination,
            "date_from": self._kiwi_date(date_from),
            "date_to": self._kiwi_date(date_to),
            "nights_in_dst_from": min_nights,
            "nights_in_dst_to": max_nights,
            "flight_type": "round",
            "curr": "EUR",
            "limit": 5,
            "sort": "price",
        }
        headers = {"apikey": self.api_key}

        try:
            resp = requests.get(KIWI_API_URL, params=params, headers=headers, timeout=20)
            resp.raise_for_status()
            data = resp.json()
        except requests.RequestException as exc:
            logger.error("Kiwi API request failed: %s", exc)
            return []

        results = []
        for item in data.get("data", []):
            try:
                results.append(self._parse(item))
            except (KeyError, TypeError, ValueError) as exc:
                logger.debug("Skipping malformed Kiwi result: %s", exc)

        return results

    @staticmethod
    def _parse(item: dict) -> dict:
        """Normalise a Kiwi result dict into the standard adapter format."""
        # Kiwi returns Unix timestamps; convert to YYYY-MM-DD
        outbound_ts = item["dTime"]
        return_ts = item["aTimeReturn"] if "aTimeReturn" in item else item["dTimeReturn"]

        outbound_date = datetime.utcfromtimestamp(outbound_ts).strftime("%Y-%m-%d")
        return_date = datetime.utcfromtimestamp(return_ts).strftime("%Y-%m-%d")

        # Carrier: prefer marketing airline of first leg
        try:
            carrier = item["airlines"][0]
        except (KeyError, IndexError):
            carrier = "unknown"

        return {
            "price_eur": float(item["price"]),
            "outbound_date": outbound_date,
            "return_date": return_date,
            "deep_link": item.get("deep_link", ""),
            "carrier": carrier,
        }

    @staticmethod
    def _kiwi_date(iso_date: str) -> str:
        """Convert YYYY-MM-DD → DD/MM/YYYY (Kiwi format)."""
        dt = datetime.strptime(iso_date, "%Y-%m-%d")
        return dt.strftime("%d/%m/%Y")