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

events {
    worker_connections 1024;
    use epoll;
}

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;

    # Performance optimizations for 2 vCPU
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    client_max_body_size 50M;

    # Gzip compression
    gzip on;
    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 application/atom+xml image/svg+xml 
               text/x-component text/x-cross-domain-policy;
    gzip_disable "msie6";

    # Rate limiting (prevent abuse)
    limit_req_zone $binary_remote_addr zone=api_limit:10m rate=100r/s;
    limit_req_zone $binary_remote_addr zone=general_limit:10m rate=30r/s;

    # Upstream Paperclip
    upstream paperclip {
        server paperclip:3000;
    }

    # HTTP server (redirect to HTTPS)
    server {
        listen 80;
        server_name _;
        
        location /.well-known/acme-challenge/ {
            root /usr/share/nginx/html;
        }

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

    # HTTPS server (main)
    server {
        listen 443 ssl http2;
        server_name _;

        # SSL Configuration (update paths after Let's Encrypt setup)
        ssl_certificate /etc/nginx/ssl/cert.pem;
        ssl_certificate_key /etc/nginx/ssl/key.pem;
        
        # SSL Security
        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;

        # Access logging
        access_log /var/log/nginx/ezygas_access.log main;
        error_log /var/log/nginx/ezygas_error.log warn;

        # Health check endpoint (no auth required)
        location /health {
            access_log off;
            proxy_pass http://paperclip;
            proxy_http_version 1.1;
        }

        # API endpoints (rate limited)
        location /api/ {
            limit_req zone=api_limit burst=20 nodelay;
            
            proxy_pass http://paperclip;
            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_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
            proxy_connect_timeout 60s;
            proxy_send_timeout 60s;
            proxy_read_timeout 60s;
        }

        # Main application (rate limited)
        location / {
            limit_req zone=general_limit burst=10 nodelay;
            
            proxy_pass http://paperclip;
            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_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
            
            # Timeouts for long-running requests
            proxy_connect_timeout 60s;
            proxy_send_timeout 300s;
            proxy_read_timeout 300s;
            
            # Buffering for large responses
            proxy_buffering on;
            proxy_buffer_size 4k;
            proxy_buffers 8 4k;
            proxy_busy_buffers_size 8k;
        }

        # Deny access to sensitive files
        location ~ /\. {
            deny all;
            access_log off;
            log_not_found off;
        }
    }
}