upstream liberdiscovery_api {
    server liberdiscovery-api:8080;
    keepalive 32;
}

upstream zabbix_web {
    server zabbix-web:8080;
}

# Rate limiting zones
limit_req_zone $binary_remote_addr zone=api:10m rate=30r/s;
limit_req_zone $binary_remote_addr zone=discovery:10m rate=2r/m;

server {
    listen 80;
    server_name _;
    
    # Redirect to HTTPS in production
    # return 301 https://$host$request_uri;

    # Security headers
    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 "strict-origin-when-cross-origin" always;

    # Gzip compression
    gzip on;
    gzip_types text/plain text/css application/json application/javascript text/xml application/xml image/svg+xml;
    gzip_min_length 1000;
    gzip_comp_level 6;

    # ─── React Frontend (SPA) ─────────────────────────────────────────
    location / {
        root /usr/share/nginx/html;
        index index.html;
        try_files $uri $uri/ /index.html;

        # Cache static assets
        location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot)$ {
            expires 30d;
            add_header Cache-Control "public, immutable";
        }
    }

    # ─── LiberDiscovery Go API ──────────────────────────────────────────────
    location /api/ {
        limit_req zone=api burst=50 nodelay;
        
        proxy_pass http://liberdiscovery_api;
        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_read_timeout 300s;
        proxy_send_timeout 300s;
        proxy_connect_timeout 60s;
        
        # CORS headers (also set in Go, but belt+suspenders)
        add_header Access-Control-Allow-Origin "*" always;
        add_header Access-Control-Allow-Methods "GET, POST, PUT, DELETE, OPTIONS" always;
        add_header Access-Control-Allow-Headers "Origin, Content-Type, Accept, Authorization" always;
        
        if ($request_method = OPTIONS) {
            return 204;
        }
    }

    # ─── Discovery endpoint (stricter rate limit) ─────────────────────
    location /api/v1/discovery/scan {
        limit_req zone=discovery burst=3 nodelay;
        
        proxy_pass http://liberdiscovery_api;
        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_read_timeout 600s;
    }

    # ─── WebSocket ────────────────────────────────────────────────────
    location /ws {
        proxy_pass http://liberdiscovery_api;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_read_timeout 86400s;
        proxy_send_timeout 86400s;
    }

    # ─── Zabbix Frontend ──────────────────────────────────────────────
    location /zabbix/ {
        proxy_pass http://zabbix_web/;
        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 for load balancers ──────────────────────────────
    location /health {
        proxy_pass http://liberdiscovery_api/api/v1/health;
        access_log off;
    }

    # Block common attack paths
    location ~ /\. { deny all; }
    location ~ ~$ { deny all; }
}

# HTTPS server (uncomment when SSL certs are ready)
# server {
#     listen 443 ssl http2;
#     server_name liberdiscovery.example.com;
#     
#     ssl_certificate /etc/nginx/ssl/cert.pem;
#     ssl_certificate_key /etc/nginx/ssl/key.pem;
#     ssl_protocols TLSv1.2 TLSv1.3;
#     ssl_prefer_server_ciphers on;
#     ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256;
#     
#     # HSTS
#     add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
#     
#     # ... same location blocks as above ...
# }