upstream hms_backend {
    server app:3000;
    keepalive 32;
}

server {
    listen 80;
    server_name _;
    return 301 https://$host$request_uri;
}

server {
    listen 443 ssl http2;
    server_name _;

    # ── TLS ──
    ssl_certificate     /etc/nginx/ssl/fullchain.pem;
    ssl_certificate_key /etc/nginx/ssl/privkey.pem;
    ssl_protocols       TLSv1.2 TLSv1.3;
    ssl_ciphers         ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384;
    ssl_prefer_server_ciphers off;
    ssl_session_cache   shared:SSL:10m;
    ssl_session_timeout 1d;
    ssl_session_tickets off;

    # ── 安全头 ──
    add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-Frame-Options "DENY" always;
    add_header X-XSS-Protection "1; mode=block" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
    add_header Permissions-Policy "camera=(), microphone=(), geolocation=()" always;
    add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; img-src 'self' data: blob:; font-src 'self'; connect-src 'self' wss:; frame-ancestors 'none'" always;

    # ── 日志 ──
    access_log /var/log/nginx/hms_access.log;
    error_log  /var/log/nginx/hms_error.log warn;

    # ── 上传文件（化验单/体检报告）──
    location /uploads/ {
        proxy_pass http://hms_backend;
        proxy_set_header Host $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;
        # 大文件上传限制
        client_max_body_size 50m;
    }

    # ── SSE（消息推送/AI 分析）──
    location ~ ^/api/v1/(message|ai)/.*sse {
        proxy_pass http://hms_backend;
        proxy_set_header Host $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;
        proxy_http_version 1.1;
        proxy_set_header Connection "";
        proxy_buffering off;
        proxy_cache off;
        proxy_read_timeout 86400s;
        chunked_transfer_encoding on;
    }

    # ── API 反代 ──
    location /api/ {
        proxy_pass http://hms_backend;
        proxy_set_header Host $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;
        proxy_http_version 1.1;
        proxy_set_header Connection "";
        client_max_body_size 50m;
    }

    # ── 健康检查 ──
    location /health {
        proxy_pass http://hms_backend/api/v1/health;
        access_log off;
    }

    # ── 指标（仅内网可访问）──
    location /metrics {
        # 生产环境应限制为 Prometheus 访问
        allow 172.16.0.0/12;
        allow 10.0.0.0/8;
        deny all;
        proxy_pass http://hms_backend:9090/metrics;
        access_log off;
    }

    location / {
        return 404;
    }
}