events {
    worker_connections 1024;
}

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

    # Logging Formats
    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 warn;

    # Performance & Security Controls
    sendfile        on;
    tcp_nopush      on;
    tcp_nodelay     on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    server_tokens off;

    # Gzip Compression
    gzip on;
    gzip_disable "msie6";
    gzip_comp_level 6;
    gzip_min_length 256;
    gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript image/svg+xml;

    # Rate Limiting Zones
    limit_req_zone $binary_remote_addr zone=api_limit:10m rate=15r/s;

    # Upstream Clusters
    upstream frontend_cluster {
        server frontend:3000;
    }

    upstream backend_cluster {
        server backend:5000;
    }

    # HTTP Server (Redirects to HTTPS in production)
    server {
        listen 80;
        server_name indianbooksworldwide.com www.indianbooksworldwide.com;

        location /.well-known/acme-challenge/ {
            root /var/www/certbot;
        }

        location / {
            return 301 https://$host$request_uri;
        }
    }

    # HTTPS SSL Server
    server {
        listen 443 ssl http2;
        server_name indianbooksworldwide.com www.indianbooksworldwide.com;

        ssl_certificate /etc/letsencrypt/live/indianbooksworldwide.com/fullchain.pem;
        ssl_certificate_key /etc/letsencrypt/live/indianbooksworldwide.com/privkey.pem;

        ssl_protocols TLSv1.2 TLSv1.3;
        ssl_ciphers HIGH:!aNULL:!MD5;
        ssl_prefer_server_ciphers on;

        # Frontend Next.js SSR Routing
        location / {
            proxy_pass http://frontend_cluster;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection 'upgrade';
            proxy_set_header Host $host;
            proxy_cache_bypass $http_upgrade;
        }

        # Backend Express API Routing
        location /api/ {
            limit_req zone=api_limit burst=20 nodelay;
            proxy_pass http://backend_cluster;
            proxy_http_version 1.1;
            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;
        }
    }
}