import logging
from models import POI
from abc import ABC, abstractmethod
from dataclasses import asdict
from pathlib import Path
import json


logger = logging.getLogger(__name__)


class StorageError(Exception):
    pass


class StorageWriter(ABC):
    """Write-only Interface. Klassen MÜSSEN explizit erben."""

    @abstractmethod
    def store(self, results: list[POI]) -> str:
        """
        Speichert eine Liste von POIs.
        Returns:
            str: Identifier der gespeicherten Ressource.
        Raises:
            StorageError: Bei Schreibfehlern.
        """
        raise NotImplementedError


class JsonStorage(StorageWriter):
    """
    """
    def __init__(self, output_dir: Path = Path(".")):
        self.output_dir = output_dir
        self._path = self.output_dir / "pois.json"

    def store(self, results: list[POI]) -> str:
        try:
            with self._path.open("w", encoding="utf-8") as f:
                json.dump([asdict(poi) for poi in results], f, indent=2, ensure_ascii=False)
        except OSError as exc:
            logger.error(f"Fehler beim Speichern: {exc}")
            raise StorageError("Fehler beim Speichern der POIs") from exc
        return str(self._path.resolve())



class PostgresStorage(StorageWriter):
    def __init__(self, connection_string: str, table: str = "pois"):
        pass

    def store(self, results: list[POI]) -> str:
        raise NotImplementedError