# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: Apache-2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


import asyncio
import logging
import threading
import traceback
import weakref
from enum import Enum
from queue import Queue
from typing import Any, Callable, Coroutine, Optional, TypedDict, Union

logger = logging.getLogger(__name__)

AsyncTask = Union[Callable[..., Coroutine[Any, Any, bool]], weakref.WeakMethod]


class RoutingStrategy(Enum):
    ROUND_ROBIN = "round_robin"
    RANDOM = "random"
    PREFIX = "prefix"


class RequestType(Enum):
    CHAT = "chat"
    COMPLETION = "completion"


class ServerType(Enum):
    # Generation server used for disaggregated and aggregated requests
    GEN = "gen"
    # Context server used for disaggregated requests
    CTX = "ctx"
    # Dynamo run server used for Dynamo run requests
    DYN_RUN = "dyn_run"


class ConversationMessage(TypedDict):
    role: str
    content: str


class ManagedThread(threading.Thread):
    def __init__(
        self,
        task: Optional[AsyncTask],
        error_queue: Optional[Queue] = None,
        name: Optional[str] = None,
        loop: Optional[asyncio.AbstractEventLoop] = None,
        **kwargs,
    ):
        super().__init__(name=name)
        self.task = task
        self.error_queue = error_queue
        self.kwargs = kwargs
        self.loop = loop
        self.daemon = True

        self.stop_event = threading.Event()

    def set_loop(self, loop: asyncio.AbstractEventLoop):
        self.loop = loop

    def run(self):
        while not self.stop_event.is_set():
            task: Optional[AsyncTask] = self.task
            if isinstance(task, weakref.WeakMethod):
                task = task()
                if task is None:
                    # Normally, this should not happen.
                    logger.warning("WeakMethod is expired.")
                    break

            if task is None:
                break

            try:
                if self.loop is None:
                    logger.error("[ManagedThread] Loop not initialized!")
                    break
                future = asyncio.run_coroutine_threadsafe(
                    task(**self.kwargs), self.loop
                )
                _ = future.result()
            except Exception as e:
                logger.error(
                    f"Error in thread {self.name}: {e}\n{traceback.format_exc()}"
                )
                if self.error_queue is not None:
                    self.error_queue.put(e)

        logger.info(f"Thread {self.name} stopped.")

    def stop(self):
        self.stop_event.set()
