from django.http import StreamingHttpResponse
from django.views import View
import time

# 定義生成器函數(shù)，用于逐塊生成數(shù)據(jù)
def stream_generator():
    """生成器函數(shù)，逐行返回?cái)?shù)據(jù)（模擬實(shí)時(shí)生成內(nèi)容）"""
    for i in range(5):
        # 模擬耗時(shí)操作（如讀取大文件、實(shí)時(shí)計(jì)算）
        time.sleep(1)
        # 每塊數(shù)據(jù)末尾加換行符，讓客戶端能實(shí)時(shí)看到
        yield f"這是第 {i+1} 塊數(shù)據(jù)\n"

class StreamView(View):
    def get(self, request):
        # 創(chuàng)建 StreamingHttpResponse，傳入生成器
        response = StreamingHttpResponse(stream_generator())
        # 設(shè)置響應(yīng)頭，確?？蛻舳税戳魈幚恚蛇x但推薦）
        response['Content-Type'] = 'text/plain; charset=utf-8'
        # 禁用緩存，確保數(shù)據(jù)實(shí)時(shí)推送
        response['Cache-Control'] = 'no-cache'
        # 添加流式傳輸 headers，禁用緩沖
        # 注意：Transfer-Encoding 和 Connection 是 hop-by-hop headers，由 WSGI 服務(wù)器自動(dòng)處理，不能在應(yīng)用層設(shè)置
        # response['Cache-Control'] = 'no-cache, no-store, must-revalidate'
        # response['Pragma'] = 'no-cache'
        # response['Expires'] = '0'
        # response['X-Accel-Buffering'] = 'no'  # 禁用 Nginx 緩沖

        # logger.info(f"[StreamingView] StreamingHttpResponse 已創(chuàng)建，headers 已配置用于流式傳輸")
        return response

from django.http import StreamingHttpResponse
from django.views import View
import os

def file_stream_generator(file_path, chunk_size=8192):
    """讀取文件并逐塊生成數(shù)據(jù)"""
    with open(file_path, 'rb') as f:
        while chunk := f.read(chunk_size):
            yield chunk

class LargeFileDownloadView(View):
    def get(self, request):
        # 替換為你的大文件路徑
        file_path = "/path/to/your/large_file.zip"
        if not os.path.exists(file_path):
            return HttpResponse("文件不存在", status=404)
        
        # 獲取文件名
        file_name = os.path.basename(file_path)
        # 創(chuàng)建流式響應(yīng)
        response = StreamingHttpResponse(
            file_stream_generator(file_path),
            content_type='application/octet-stream'  # 二進(jìn)制文件類型
        )
        # 設(shè)置下載頭，指定文件名
        response['Content-Disposition'] = f'attachment; filename="{file_name}"'
        # 設(shè)置分塊傳輸編碼
        response['Transfer-Encoding'] = 'chunked'
        return response

from django.http import StreamingHttpResponse
from django.views import View
import time
import json

def sse_generator():
    """生成 SSE 格式的實(shí)時(shí)數(shù)據(jù)"""
    for i in range(10):
        time.sleep(1)
        # SSE 格式要求：data: 內(nèi)容\n\n
        data = json.dumps({"progress": i * 10, "message": f"處理中 {i*10}%"})
        yield f"data: {data}\n\n"

class SSEView(View):
    def get(self, request):
        response = StreamingHttpResponse(sse_generator())
        # SSE 專用 Content-Type
        response['Content-Type'] = 'text/event-stream'
        # 禁用緩存和超時(shí)
        response['Cache-Control'] = 'no-cache'
        response['X-Accel-Buffering'] = 'no'  # 禁用 nginx 緩沖（關(guān)鍵）
        return response

from django.urls import path
from .views import StreamView, LargeFileDownloadView, SSEView

urlpatterns = [
    path('stream/', StreamView.as_view(), name='stream'),
    path('download-large-file/', LargeFileDownloadView.as_view(), name='download'),
    path('sse/', SSEView.as_view(), name='sse'),
]