map $http_upgrade $connection_upgrade {
    default upgrade;
    ''      close;
}

server {
    listen 80;
    server_name localhost;

    location ~ ^/jupyter/(?<workspace_id>[^/]+)/?$ {
        return 403 "Direct directory access is forbidden. Please specify a notebook path.";
    }

    # 精准匹配入口：仅允许访问特定 notebook 页面与配套资源
    location ~ ^/jupyter/(?<workspace_id>[^/]+)(?<rest_uri>/.*)$ {

        # 触发后端鉴权
        auth_request /internal-auth;

        auth_request_set $target_upstream $upstream_http_x_upstream_addr;
        auth_request_set $jupyter_token $upstream_http_x_jupyter_internal_token;

        # 拼接完整 URL 并输出到 Response Header 方便调试
        add_header X-Debug-Full-Url "$target_upstream/jupyter/$workspace_id$rest_uri$is_args$args" always;

        # 代理到具体的 Jupyter 子进程
        proxy_pass $target_upstream/jupyter/$workspace_id$rest_uri$is_args$args;
        proxy_set_header Authorization "token $jupyter_token";

        # 支持 WebSocket (Jupyter Kernel 必需)
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;

        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }

    # 2. 内部 Auth 子请求 location
    location = /internal-auth {
        internal;
        # 打到宿主机的 FastAPI 8000 端口
        proxy_pass http://host.docker.internal:8000/api/v1/auth/jupyter;

        proxy_pass_request_body off;
        proxy_set_header Content-Length "";

        proxy_pass_header x-upstream-addr;
        proxy_pass_header x-jupyter-internal-token;

        proxy_set_header X-Original-Workspace-Id $workspace_id;
        proxy_set_header X-Original-URI $request_uri;

        proxy_set_header Cookie $http_cookie;
        proxy_set_header Authorization $http_authorization;
    }

    # 拒绝其余非法路径
    location /jupyter/ {
        return 403 "Access Denied";
    }
}