import asyncio
from contextlib import asynccontextmanager
from functools import partial

from fastapi import APIRouter, FastAPI, status
from graphiti_core.nodes import EpisodeType  # type: ignore
from graphiti_core.utils import clear_data  # type: ignore

from graph_service.dto import AddMessagesRequest, Message, Result
from graph_service.zep_graphiti import ZepGraphitiDep


class AsyncWorker:
    def __init__(self):
        self.queue = asyncio.Queue()
        self.task = None

    async def worker(self):
        while True:
            try:
                print(f'Got a job: (size of remaining queue: {self.queue.qsize()})')
                job = await self.queue.get()
                await job()
            except asyncio.CancelledError:
                break

    async def start(self):
        self.task = asyncio.create_task(self.worker())

    async def stop(self):
        if self.task:
            self.task.cancel()
            await self.task
        while not self.queue.empty():
            self.queue.get_nowait()


async_worker = AsyncWorker()


@asynccontextmanager
async def lifespan(_: FastAPI):
    await async_worker.start()
    yield
    await async_worker.stop()


router = APIRouter(lifespan=lifespan)


@router.post('/messages', status_code=status.HTTP_202_ACCEPTED)
async def add_messages(
    request: AddMessagesRequest,
    graphiti: ZepGraphitiDep,
):
    async def add_messages_task(m: Message):
        # Will pass a group_id to the add_episode call once it is implemented
        await graphiti.add_episode(
            name=m.name,
            episode_body=f"{m.role or ''}({m.role_type}): {m.content}",
            reference_time=m.timestamp,
            source=EpisodeType.message,
            source_description=m.source_description,
        )

    for m in request.messages:
        await async_worker.queue.put(partial(add_messages_task, m))

    return Result(message='Messages added to processing queue', success=True)


@router.post('/clear', status_code=status.HTTP_200_OK)
async def clear(
    graphiti: ZepGraphitiDep,
):
    await clear_data(graphiti.driver)
    await graphiti.build_indices_and_constraints()
    return Result(message='Graph cleared', success=True)