import redis
import hashlib
import json
from typing import Optional, Dict, Any


class ChatData:
    def __init__(self, chat_id: str = "", current_message_id: str = ""):
        self.chat_id = chat_id
        self.current_message_id = current_message_id

    def serialize(self) -> str:
        """Serialize to string format"""
        return f"{self.chat_id};{self.current_message_id}"

    @staticmethod
    def deserialize(text: str) -> 'ChatData':
        """Deserialize from string format"""
        parts = text.split(';')
        if len(parts) > 2:
            raise ValueError("Invalid cache data")

        chat_id = parts[0] if len(parts) > 0 else ""
        current_message_id = parts[1] if len(parts) > 1 else ""

        return ChatData(chat_id=chat_id, current_message_id=current_message_id)


class Cache:
    def __init__(self, redis_addr: str = "localhost:6379"):
        """Initialize cache with Redis connection"""
        host, port = redis_addr.split(':')
        self.redis = redis.Redis(host=host, port=int(port), decode_responses=True)
        # Test connection
        self.redis.ping()

    def _get_key(self, token: str, title: str) -> str:
        """Generate cache key using FNV-1a hash"""
        combined = f"{token};{title}"
        # Simple FNV-1a hash implementation
        hash_value = 0xcbf29ce484222325
        for byte in combined.encode('utf-8'):
            hash_value ^= byte
            hash_value = (hash_value * 0x100000001b3) & 0xffffffffffffffff
        return str(hash_value)

    def get_chat_data(self, token: str, title: str) -> ChatData:
        """Get chat data from cache"""
        key = self._get_key(token, title)
        data = self.redis.get(key)

        if data is None:
            return ChatData(chat_id="", current_message_id="")

        return ChatData.deserialize(data)

    def set_chat_data(self, token: str, title: str, data: ChatData) -> None:
        """Set chat data in cache"""
        key = self._get_key(token, title)
        self.redis.set(key, data.serialize())

    def close(self):
        """Close Redis connection"""
        self.redis.close()