import json
from datetime import datetime
from pathlib import Path
from typing import Any, Optional, Dict, List

from fastmcp import FastMCP
from pydantic import BaseModel, ValidationError


class MemoryEntry(BaseModel):
    value: Any
    timestamp: str


class MemoryServer:
    def __init__(self):
        self.mcp = FastMCP("Memory-Server")
        self.storage_path = Path("./memory_data.json")
        # Register tools
        self.mcp.tool()(self.save)
        self.mcp.tool()(self.get)
        self.mcp.tool()(self.delete)
        self.mcp.tool()(self.list_keys)
        self.mcp.tool()(self.save_with_namespace)
        self.mcp.tool()(self.get_with_namespace)
        self.mcp.tool()(self.delete_with_namespace)
        self.mcp.tool()(self.list_keys_with_namespace)

    def _load_memory(self) -> Dict[str, Dict[str, Any]]:
        """Загружает память из JSON-файла."""
        if not self.storage_path.exists():
            return {}
        try:
            with open(self.storage_path, "r", encoding="utf-8") as f:
                data = json.load(f)
                # Validate structure
                validated = {}
                for k, v in data.items():
                    try:
                        entry = MemoryEntry(**v)
                        validated[k] = entry.dict()
                    except ValidationError:
                        # Skip invalid entries
                        continue
                return validated
        except (json.JSONDecodeError, OSError):
            return {}

    def _save_memory(self, data: Dict[str, Dict[str, Any]]) -> None:
        """Сохраняет память в JSON-файл."""
        self.storage_path.parent.mkdir(parents=True, exist_ok=True)
        try:
            with open(self.storage_path, "w", encoding="utf-8") as f:
                json.dump(data, f, indent=2, ensure_ascii=False)
        except OSError as e:
            # Log error if needed
            print(f"Error saving memory: {e}")

    # Core CRUD operations

    def save(self, key: str, value: Any) -> bool:
        """Сохраняет значение по ключу в память сервера."""
        data = self._load_memory()
        entry = {"value": value, "timestamp": datetime.utcnow().isoformat()}
        data[key] = entry
        self._save_memory(data)
        return True

    def get(self, key: str) -> Optional[Dict[str, Any]]:
        """Возвращает значение по ключу с метаданными."""
        data = self._load_memory()
        entry = data.get(key)
        return entry if entry else None

    def delete(self, key: str) -> bool:
        """Удаляет ключ из памяти."""
        data = self._load_memory()
        if key in data:
            del data[key]
            self._save_memory(data)
            return True
        return False

    def list_keys(self) -> List[str]:
        """Возвращает список всех ключей."""
        data = self._load_memory()
        return list(data.keys())

    # Namespace-aware operations

    def _compose_key(self, namespace: str, key: str) -> str:
        return f"{namespace}:{key}"

    def save_with_namespace(self, namespace: str, key: str, value: Any) -> bool:
        composite = self._compose_key(namespace, key)
        return self.save(composite, value)

    def get_with_namespace(self, namespace: str, key: str) -> Optional[Dict[str, Any]]:
        composite = self._compose_key(namespace, key)
        return self.get(composite)

    def delete_with_namespace(self, namespace: str, key: str) -> bool:
        composite = self._compose_key(namespace, key)
        return self.delete(composite)

    def list_keys_with_namespace(self, namespace: str) -> List[str]:
        data = self._load_memory()
        prefix = f"{namespace}:"
        return [k[len(prefix) :] for k in data.keys() if k.startswith(prefix)]


if __name__ == "__main__":
    server = MemoryServer()
    print("Starting Memory MCP Server...")
    server.mcp.run()