server {
    listen 80;
    server_name localhost;
    root /usr/share/nginx/html;
    index index.html;
    
    # Enable gzip compression
    gzip on;
    gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;

    # Protect all routes with basic authentication
    location / {
        # Include authentication configuration
        include /etc/nginx/auth.conf;
        
        # Serve static files
        try_files $uri $uri/ =404;
        
        # CORS headers
        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, X-Requested-With, Content-Type, Accept, Authorization' always;
        
        # Handle preflight requests
        if ($request_method = 'OPTIONS') {
            add_header 'Access-Control-Allow-Origin' '*';
            add_header 'Access-Control-Allow-Methods' 'GET, POST, PUT, DELETE, OPTIONS';
            add_header 'Access-Control-Allow-Headers' 'Origin, X-Requested-With, Content-Type, Accept, Authorization';
            add_header 'Access-Control-Max-Age' 1728000;
            add_header 'Content-Type' 'text/plain charset=UTF-8';
            add_header 'Content-Length' 0;
            return 204;
        }
    }
    
    # Special location for index.html to avoid redirection loops
    location = /index.html {
        # Include authentication configuration
        include /etc/nginx/auth.conf;
        
        # CORS headers
        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, X-Requested-With, Content-Type, Accept, Authorization' always;
    }

    # Proxy requests to the data API - no auth required for API endpoints
    location /data/ {
        # No authentication for data API to allow the app to save/load data
        auth_basic off; # Explicitly disable auth for data API
        proxy_pass http://localhost:3000/data/;
        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;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        
        # CORS headers for data API
        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, X-Requested-With, Content-Type, Accept, Authorization' always;
        
        # Handle preflight requests for the API
        if ($request_method = 'OPTIONS') {
            add_header 'Access-Control-Allow-Origin' '*';
            add_header 'Access-Control-Allow-Methods' 'GET, POST, PUT, DELETE, OPTIONS';
            add_header 'Access-Control-Allow-Headers' 'Origin, X-Requested-With, Content-Type, Accept, Authorization';
            add_header 'Access-Control-Max-Age' 1728000;
            add_header 'Content-Type' 'text/plain charset=UTF-8';
            add_header 'Content-Length' 0;
            return 204;
        }
    }

    # Enable browser caching for static assets
    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg)$ {
        expires 30d;
        add_header Cache-Control "public, no-transform";
        add_header 'Access-Control-Allow-Origin' '*' always;
    }

    # Error pages
    error_page 404 /index.html;
    error_page 500 502 503 504 /50x.html;
    location = /50x.html {
        root /usr/share/nginx/html;
    }
}