import asyncio
from typing import Any, Dict, List, Optional


class AsyncDictStore:
    """A small async-safe in-memory key-value store for dict items.

    This encapsulates the usual pattern of a module-level dict guarded by
    an asyncio.Lock and provides simple CRUD methods that are safe to call
    concurrently from FastAPI request handlers and background tasks.
    """

    def __init__(self) -> None:
        self._items: Dict[str, Dict[str, Any]] = {}
        self._lock = asyncio.Lock()

    async def upsert(self, key: str, value: Dict[str, Any]) -> None:
        async with self._lock:
            self._items[key] = value

    async def update_fields(
        self, key: str, updates: Dict[str, Any]
    ) -> Optional[Dict[str, Any]]:
        async with self._lock:
            item = self._items.get(key)
            if item is None:
                return None
            item.update(updates)
            return item

    async def get(self, key: str) -> Optional[Dict[str, Any]]:
        async with self._lock:
            return self._items.get(key)

    async def pop(self, key: str) -> Optional[Dict[str, Any]]:
        async with self._lock:
            return self._items.pop(key, None)

    async def list_values(self) -> List[Dict[str, Any]]:
        async with self._lock:
            return list(self._items.values())


# Global stores shared by OpenAI entrypoints
# [request_id, dict]
VIDEO_STORE = AsyncDictStore()
IMAGE_STORE = AsyncDictStore()
MESH_STORE = AsyncDictStore()