from django.http.response import StreamingHttpResponse
from rest_framework.decorators import api_view, permission_classes
from rest_framework.response import Response
from contextlib import suppress
import asyncio


_connections = set()


@api_view(['POST'])
@permission_classes([])
def create_sse_event(request):
    """
    创建一个简单的SSE事件流响应，用于测试和演示目的。
    """

    def sse_stream():
        queue = asyncio.Queue()
        _connections.add(queue)

        try:
            while True:
                data = queue.get()
                yield f"data: {data}\n\n"
        finally:
            _connections.remove(queue)

    response = StreamingHttpResponse(sse_stream(), content_type='text/event-stream')
    response['Cache-Control'] = 'no-cache'
    return response


@api_view(['POST'])
@permission_classes([])
def push_sse_event(request):
    """
    向所有连接的客户端广播一个SSE事件。
    请求体应包含一个 'message' 字段，表示要发送的消息内容。
    """
    message = request.data.get('message', 'Hello, SSE!')
    for q in list(_connections):
        with suppress(asyncio.QueueFull):
            q.put_nowait(message)
    return Response({'status': 'message sent'})