# ----------------------------------------------------------------------------
# NOTE: this file is mounted into the nginx container as a TEMPLATE.
# scripts/nginx-entrypoint.sh (mounted as /docker-entrypoint.sh) substitutes
# the single ${S3_ENDPOINT} placeholder at container start. The rendered
# output is written to /etc/nginx/conf.d/default.conf and execs nginx.
# ----------------------------------------------------------------------------

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

server {
    listen 80;
    server_name localhost;
    # 全局或针对存储服务设置最大上传限制 (100G)
    client_max_body_size 100G;
    # 指定 Docker 内置 DNS 解析器，并设置 30 秒缓存
    resolver 127.0.0.11 valid=30s ipv6=off;

    # S3 upstream — full URL passed through to proxy_pass below.
    set $s3_backend "${S3_ENDPOINT}";

    location / {
        root   /usr/share/nginx/html;       # 前端静态文件存放在容器中的路径
        index  index.html index.htm;

        # 核心：支持 SPA 路由（前端 React Router / Vue Router 刷新不报 404）
        try_files $uri $uri/ /index.html;
    }

    #（可选）针对静态文件资源加长期缓存优化
#     location ~* \.(?:css|js|jpg|jpeg|gif|png|ico|cur|gz|svg|svgz|mp4|ogg|ogv|webm|htc|woff|woff2)$ {
#         root /usr/share/nginx/html;
#         expires 2h; # 前端静态缓存2小时
#         add_header Cache-Control "public, no-transform";
#     }

    location /api/ {
        proxy_pass http://backend:8000/api/;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-Host $http_host;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        # Explicitly forward the session cookie set by
        # POST /api/v1/auth/login. nginx forwards it by default, but
        # spelling it out keeps the auth contract visible.
        proxy_set_header Cookie $http_cookie;
        # Defense in depth: blank out the legacy identity headers so a
        # malicious client cannot bypass the cookie-based auth flow
        # by stuffing X-User-ID / X-Workspace-ID into the request.
        # The backend's RequestContext no longer reads them (it
        # derives identity from the access_token cookie), so this is
        # belt-and-suspenders against a future regression.
        proxy_set_header X-User-ID      "";
        proxy_set_header X-Workspace-ID "";
    }

    # =========================================================================
    # 1. S3 对象存储服务转发 (/storage/)
    # =========================================================================
    location /storage/ {
        # 核心：透传 Host，确保 S3 生成的 Presigned URL 包含公网地址
        proxy_set_header Host $http_host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;

        # 转发至 S3（$s3_backend 来自 set 指令；尾斜杠保留 location /storage/ 前缀剥离语义）
        proxy_pass $s3_backend/;

        # HTTP/1.1 长连接支持
        proxy_http_version 1.1;
        proxy_set_header Connection "";

        # 性能优化：关闭双向 Buffer，实现大文件流式传输
        proxy_buffering off;
        proxy_request_buffering off;

        # 大文件传输超时设置
        proxy_connect_timeout 300s;
        proxy_read_timeout    3600s;
        proxy_send_timeout    3600s;
    }

    # =========================================================================
    # 2. Jupyter 服务配置
    # =========================================================================
    # 拒绝直接访问目录
    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;
        # Defense in depth: do not let the browser-supplied identity
        # headers leak past the auth subrequest. The auth subrequest
        # only forwards the Cookie + Authorization it cares about;
        # the actual Jupyter upstream is fully trusted (the address
        # comes from the backend's runtime registry), so a leaked
        # X-User-ID here would not matter for the proxy target but
        # could pollute audit logs.
        proxy_set_header X-User-ID      "";
        proxy_set_header X-Workspace-ID "";
    }

    # 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://backend: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;
        # Defense in depth: the auth subrequest reads the session
        # cookie / Authorization header, not the legacy identity
        # headers. Blank them out so a poisoned client header cannot
        # be confused for an authenticated identity if the backend
        # code is ever refactored to read them again.
        proxy_set_header X-User-ID      "";
        proxy_set_header X-Workspace-ID "";
    }

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