from flask import Flask, request, Response
import requests

app = Flask(__name__)

@app.route('/', defaults={'path': ''})
@app.route('/<path:path>')
def proxy(path):
    # 解析请求 URL
    url = request.url
    url_obj = requests.compat.urlparse(url)

    # 默认目标主机为 chatgpt.com，若路径以 /assets 开头则切换为 cdn.oaistatic.com
    target_host = 'chatgpt.com'
    if url_obj.path.startswith('/assets'):
        target_host = 'cdn.oaistatic.com'

    new_url = url_obj._replace(netloc=target_host).geturl()

    # 创建新的 Headers 对象，复制原始请求头
    new_headers = dict(request.headers)

    # 设置 User-Agent 为模拟无头浏览器的标识，这里结合了 Edge 和 HeadlessChrome 的特征
    new_headers['User-Agent'] = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) HeadlessChrome/92.0.4515.107 Safari/537.36 Edg/92.0.902.55'

    # 添加额外的 HTTP 头信息以模拟无头浏览器的请求行为
    new_headers['sec-ch-ua'] = '"Chromium";v="92", " Not A;Brand";v="99", "HeadlessChrome";v="92"'
    new_headers['sec-ch-ua-mobile'] = '?0'
    new_headers['sec-ch-ua-platform'] = '"Windows"'
    new_headers['sec-fetch-site'] = 'none'
    new_headers['sec-fetch-mode'] = 'navigate'
    new_headers['sec-fetch-user'] = '?1'
    new_headers['sec-fetch-dest'] = 'document'

    # 构造新的请求，保留原有的 method、body（非 GET/HEAD 请求）
    if request.method in ['GET', 'HEAD']:
        resp = requests.request(request.method, new_url, headers=new_headers, allow_redirects=True)
    else:
        resp = requests.request(request.method, new_url, headers=new_headers, data=request.get_data(), allow_redirects=True)

    # 创建响应对象
    response = Response(resp.content, resp.status_code)
    for key, value in resp.headers.items():
        if key.lower() not in ['content-encoding', 'content-length', 'transfer-encoding', 'connection']:
            response.headers[key] = value

    return response

if __name__ == '__main__':
    app.run(debug=True)