from __future__ import annotations

import json
from typing import Any

from redis.asyncio import Redis
from redis.exceptions import RedisError


class RedisHotCache:
    """Best-effort accelerator; callers must always retain a PostgreSQL fallback."""

    def __init__(self, client: Redis | None) -> None:
        self.client = client

    async def get(self, key: str) -> dict[str, Any] | None:
        if not self.client:
            return None
        try:
            value = await self.client.get(f"han:safety:{key}")
            return json.loads(value) if value else None
        except (RedisError, ValueError, TypeError):
            return None

    async def put(self, key: str, value: dict[str, Any], ttl: int) -> None:
        if not self.client:
            return
        try:
            await self.client.set(
                f"han:safety:{key}",
                json.dumps(value, separators=(",", ":"), sort_keys=True),
                ex=ttl,
            )
        except RedisError:
            return