user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;

events {
    worker_connections 1024;
}

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

    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;

    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    client_max_body_size 10M;

    # Gzip compression
    gzip on;
    gzip_disable "msie6";
    gzip_vary on;
    gzip_proxied any;
    gzip_comp_level 6;
    gzip_types text/plain text/css text/xml text/javascript 
               application/json application/javascript application/xml+rss 
               application/rss+xml font/truetype font/opentype 
               application/vnd.ms-fontobject image/svg+xml;

    # Rate limiting
    limit_req_zone $binary_remote_addr zone=api_limit:10m rate=10r/s;
    limit_req_zone $binary_remote_addr zone=docs_limit:10m rate=30r/s;

    # Upstream servers
    upstream docs_server {
        server docs-server:8000;
    }

    upstream mcp_server {
        server docs-server:8001;
    }

    # HTTP to HTTPS redirect
    server {
        listen 80;
        server_name docs.datacenter.local;
        return 301 https://$server_name$request_uri;
    }

    # HTTPS server
    server {
        listen 443 ssl http2;
        server_name docs.datacenter.local;

        # SSL configuration
        ssl_certificate /etc/nginx/ssl/cert.pem;
        ssl_certificate_key /etc/nginx/ssl/key.pem;
        ssl_protocols TLSv1.2 TLSv1.3;
        ssl_ciphers HIGH:!aNULL:!MD5;
        ssl_prefer_server_ciphers on;
        ssl_session_cache shared:SSL:10m;
        ssl_session_timeout 10m;

        # Security headers
        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
        add_header X-Frame-Options "SAMEORIGIN" always;
        add_header X-Content-Type-Options "nosniff" always;
        add_header X-XSS-Protection "1; mode=block" always;
        add_header Referrer-Policy "no-referrer-when-downgrade" always;

        # Root location
        location / {
            limit_req zone=docs_limit burst=20 nodelay;
            proxy_pass http://docs_server;
            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;
            
            # Caching
            proxy_cache_bypass $http_upgrade;
            proxy_cache_valid 200 10m;
            proxy_cache_valid 404 1m;
        }

        # API endpoints
        location /api/ {
            limit_req zone=api_limit burst=10 nodelay;
            proxy_pass http://docs_server;
            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;
            
            # No caching for API
            proxy_no_cache 1;
            proxy_cache_bypass 1;
        }

        # MCP Server
        location /mcp/ {
            limit_req zone=api_limit burst=10 nodelay;
            proxy_pass http://mcp_server/;
            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;
        }

        # Health check
        location /health {
            access_log off;
            proxy_pass http://docs_server/health;
        }

        # Static files caching
        location ~* \.(jpg|jpeg|png|gif|ico|css|js|svg|woff|woff2|ttf|eot)$ {
            proxy_pass http://docs_server;
            expires 30d;
            add_header Cache-Control "public, immutable";
        }
    }
}