"""
审查进度SSE实时推送接口
"""

import json
import asyncio
from typing import Dict
from datetime import datetime
from pydantic import BaseModel
from fastapi import APIRouter, Query
from .schemas.error_schemas import TaskProgressErrors
from fastapi.responses import StreamingResponse
from foundation.logger.loggering import server_logger as logger
from foundation.trace.trace_context import TraceContext, auto_trace
from core.base.progress_manager import ProgressManager, sse_callback_manager

progress_manager = ProgressManager()

task_progress_router = APIRouter(prefix="/sgsc", tags=["进度推送"])

async def sse_progress_callback(callback_task_id: str, current_data: dict):
    """SSE推送回调函数 - 接收进度更新并推送到客户端"""
    await sse_manager.send_progress(callback_task_id, current_data)

class TaskProgressResponse(BaseModel):
    code: int
    data: dict


class SimpleSSEManager:
    """SSE连接管理器 - 管理客户端SSE连接和消息推送"""


    def __init__(self):
        self.connections: Dict[str, asyncio.Queue] = {}


    async def connect(self, callback_task_id: str):
        """建立SSE连接 - 创建消息队列并发送连接确认"""
        queue = asyncio.Queue()
        self.connections[callback_task_id] = queue

        await queue.put({
            "type": "connection_established",
            "callback_task_id": callback_task_id,
            "timestamp": datetime.now().isoformat()
        })

        logger.info(f"SSE连接: {callback_task_id}")
        return queue


    async def disconnect(self, callback_task_id: str):
        """断开SSE连接 - 清理连接队列"""
        if callback_task_id in self.connections:
            del self.connections[callback_task_id]
        logger.info(f"SSE连接已断开: {callback_task_id}")


    async def send_progress(self, callback_task_id: str, current_data: dict):
        """发送进度更新 - 将进度数据放入队列推送给客户端"""
        queue = self.connections.get(callback_task_id)
        if queue:
            await queue.put({
                "type": "progress_update",
                "data": current_data,
                "timestamp": datetime.now().isoformat()
            })
            logger.debug(f"SSE进度已推送: {callback_task_id}")

sse_manager = SimpleSSEManager()

def format_sse_event(event_type: str, data: str) -> str:
    """格式化SSE事件 - 按照SSE协议格式化事件数据"""
    lines = [
        f"event: {event_type}",
        f"data: {data}",
        "",
        ""
    ]
    return "\n".join(lines) + "\n" 


@task_progress_router.get("/sse/current/{callback_task_id}")
@auto_trace("callback_task_id")
async def sse_progress_stream(
    callback_task_id: str,
    user: str = Query(..., description="用户标识")
):
    """SSE实时进度推送接口 - 建立SSE连接并实时推送任务进度"""
    try:
        valid_users = {"user-001", "user-002", "user-003"}
        if user not in valid_users:
            raise TaskProgressErrors.invalid_user()
        sse_callback_manager.register_callback(callback_task_id, sse_progress_callback)

        queue = await sse_manager.connect(callback_task_id)

        async def generate_events():
            """生成SSE事件流 - 处理连接确认、进度推送和任务完成检测"""
            try:
                logger.info(f"开始SSE事件流: {callback_task_id}")

                connected_data = json.dumps({
                    "callback_task_id": callback_task_id,
                    "message": "SSE连接已建立，等待进度更新...",
                    "timestamp": datetime.now().isoformat()
                }, ensure_ascii=False)
                yield format_sse_event("connected", connected_data)

                current_progress = await progress_manager.get_progress(callback_task_id)
                if current_progress:
                    progress_json = json.dumps(current_progress, ensure_ascii=False)
                    yield format_sse_event("current", progress_json)

                logger.debug(f"开始监听队列中的进度更新: {callback_task_id}")

                while True:
                    try:
                        message = await queue.get()

                        if message.get("type") == "progress_update":
                            current_data = message.get("data")
                            if current_data:
                                logger.info(f"总流程处理进度: {current_data.get("message")}")

                                progress_json = json.dumps(current_data, ensure_ascii=False)
                                yield format_sse_event("current", progress_json)

                                overall_task_status = current_data.get("overall_task_status")

                                if overall_task_status in ["completed", "failed"]:
                                    completion_data = {
                                        "callback_task_id": callback_task_id,
                                        "task_status": overall_task_status,
                                        "overall_progress": current_data.get("current", 100),
                                        "timestamp": datetime.now().isoformat(),
                                        "message": "全部任务完成！"
                                    }
                                    completion_json = json.dumps(completion_data, ensure_ascii=False)
                                    yield format_sse_event("completed", completion_json)

                                    logger.info(f"全部任务完成，断开SSE连接: {callback_task_id}, 状态: {overall_task_status}")
                                    break

                        elif message.get("type") == "connection_established":
                            pass

                    except Exception as e:
                        logger.error(f"队列消息处理异常: {callback_task_id}, {e}")
                        break

            except Exception as e:
                logger.error(f"SSE事件流异常: {callback_task_id}, {e}")
                error_data = json.dumps({
                    "error": f"SSE异常: {str(e)}",
                    "timestamp": datetime.now().isoformat()
                }, ensure_ascii=False)
                yield format_sse_event("error", error_data)

            finally:
                sse_callback_manager.unregister_callback(callback_task_id)
                await sse_manager.disconnect(callback_task_id)
                logger.debug(f"SSE流已结束: {callback_task_id}")

        return StreamingResponse(
            generate_events(),
            media_type="text/event-stream",
            headers={
                "Cache-Control": "no-cache, no-store, must-revalidate",
                "Connection": "keep-alive",
                "Access-Control-Allow-Origin": "*",
                "Access-Control-Allow-Headers": "Cache-Control, EventSource",
                "Access-Control-Allow-Methods": "GET, POST, OPTIONS",
                "X-Accel-Buffering": "no",  
                "X-Content-Type-Options": "nosniff"
            }
        )

    except Exception as e:
        logger.error(f"SSE连接失败: {callback_task_id}, {e}")
        raise TaskProgressErrors.server_internal_error(e)


@task_progress_router.get("/sse/status")
async def get_sse_status():
    """获取SSE连接状态 - 返回当前活跃的SSE连接信息"""
    return {
        "active_connections": len(sse_manager.connections),
        "connections": list(sse_manager.connections.keys()),
        "timestamp": datetime.now().isoformat()
    }