import asyncio
from uuid import UUID, uuid4

from app.models import CurrentStatus, Monitor, MonitorCreate, MonitorUpdate, utc_now


class MonitorStore:
    def __init__(self) -> None:
        self._lock = asyncio.Lock()
        self._items: dict[UUID, Monitor] = {}

    async def create(self, value: MonitorCreate) -> Monitor:
        now = utc_now()
        item = Monitor(
            id=uuid4(), name=value.name, url=value.url, created_at=now, updated_at=now, revision=1
        )
        async with self._lock:
            self._items[item.id] = item
        return item.model_copy(deep=True)

    async def list(self) -> list[Monitor]:
        async with self._lock:
            values = sorted(self._items.values(), key=lambda item: item.created_at)
            return [item.model_copy(deep=True) for item in values]

    async def get(self, monitor_id: UUID) -> Monitor | None:
        async with self._lock:
            item = self._items.get(monitor_id)
            return item.model_copy(deep=True) if item else None

    async def update(self, monitor_id: UUID, value: MonitorUpdate) -> Monitor | None:
        async with self._lock:
            old = self._items.get(monitor_id)
            if old is None:
                return None
            changed_url = old.url != value.url
            item = old.model_copy(
                update={
                    "name": value.name,
                    "url": value.url,
                    "updated_at": utc_now(),
                    "revision": old.revision + 1,
                    "current_status": None if changed_url else old.current_status,
                }
            )
            self._items[monitor_id] = item
            return item.model_copy(deep=True)

    async def delete(self, monitor_id: UUID) -> bool:
        async with self._lock:
            return self._items.pop(monitor_id, None) is not None

    async def set_status_if_current(
        self, monitor_id: UUID, revision: int, status: CurrentStatus
    ) -> bool:
        async with self._lock:
            old = self._items.get(monitor_id)
            if old is None or old.revision != revision:
                return False
            self._items[monitor_id] = old.model_copy(
                update={"current_status": status, "updated_at": utc_now()}
            )
            return True