events {
    worker_connections 1024;
}

http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    # 日志格式
    log_format main '$remote_addr - $remote_user [$time_local] "$request" '
                    '$status $body_bytes_sent "$http_referer" '
                    '"$http_user_agent" "$http_x_forwarded_for"';

    access_log /var/log/nginx/access.log main;
    error_log /var/log/nginx/error.log;

    # 基本设置
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;

    # 文件上传大小限制
    client_max_body_size 100M;

    # Gzip压缩
    gzip on;
    gzip_vary on;
    gzip_min_length 1024;
    gzip_types
        text/plain
        text/css
        text/xml
        text/javascript
        application/javascript
        application/xml+rss
        application/json;

    # 上游服务器
    upstream dms_backend {
        server dms-compliance-tool:5050;
    }

    # HTTP服务器
    server {
        listen 80;
        server_name localhost;

        # 安全头
        add_header X-Frame-Options "SAMEORIGIN" always;
        add_header X-XSS-Protection "1; mode=block" always;
        add_header X-Content-Type-Options "nosniff" always;
        add_header Referrer-Policy "no-referrer-when-downgrade" always;
        add_header Content-Security-Policy "default-src 'self' http: https: data: blob: 'unsafe-inline'" always;

        # 代理到后端服务
        location / {
            proxy_pass http://dms_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;
            
            # 超时设置
            proxy_connect_timeout 60s;
            proxy_send_timeout 60s;
            proxy_read_timeout 60s;
        }

        # 静态文件缓存
        location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg)$ {
            proxy_pass http://dms_backend;
            proxy_set_header Host $host;
            expires 1y;
            add_header Cache-Control "public, immutable";
        }

        # 健康检查
        location /health {
            proxy_pass http://dms_backend/health;
            access_log off;
        }
    }
}