"""Device credential repository backed by Redis."""

from __future__ import annotations

from typing import Dict, List, Optional

from pydantic import BaseModel, ValidationError

from .core.logging import get_logger
from .core.services.redis_client import redis_manager

logger = get_logger()


class DeviceCredentials(BaseModel):
    """Validated credential tuple for one device."""

    device_id: str
    api_key: str
    secret: str
    is_active: bool


class DeviceRepository:
    """Loads and stores device credentials in memory for low-latency lookup."""

    def __init__(self) -> None:
        self.redis_client = redis_manager.client
        self._credentials_by_id: Dict[str, DeviceCredentials] = {}
        self._credentials_by_key: Dict[str, DeviceCredentials] = {}

    async def _load_credentials(self) -> None:
        """Read `device:*` hashes from Redis and cache them in memory."""
        if not self.redis_client:
            raise ConnectionError("Redis client is not configured.")

        logger.info("Loading device credentials from Redis")
        loaded = 0
        async for key in self.redis_client.scan_iter("device:*"):
            data = await self.redis_client.hgetall(key)
            if not data:
                continue

            data["device_id"] = key.split(":", 1)[1]
            data["is_active"] = data.get("is_active") == "1"

            try:
                creds = DeviceCredentials(**data)
            except ValidationError as exc:
                logger.error("Skipping invalid device credentials", redis_key=key, error=str(exc))
                continue

            self._credentials_by_id[creds.device_id] = creds
            self._credentials_by_key[creds.api_key] = creds
            loaded += 1

        logger.info("Device credentials loaded", count=loaded)

    def get_by_api_key(self, api_key: str) -> Optional[DeviceCredentials]:
        """Get credentials by api key."""
        return self._credentials_by_key.get(api_key)

    def get_by_device_id(self, device_id: str) -> Optional[DeviceCredentials]:
        """Get credentials by device id."""
        return self._credentials_by_id.get(device_id)

    def get_all_devices(self) -> List[DeviceCredentials]:
        """Return all loaded devices."""
        return list(self._credentials_by_id.values())

    def count(self) -> int:
        """Return count of loaded credentials."""
        return len(self._credentials_by_id)