# Nginx configuration for React SPA
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;

    # Logging
    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
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;

    # 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/x-javascript
        application/xml+rss
        application/rss+xml
        font/truetype
        font/opentype
        application/vnd.ms-fontobject
        image/svg+xml;
    gzip_disable "msie6";

    server {
        listen 80;
        server_name _;
        root /usr/share/nginx/html;
        index index.html;

        # 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;

        # Health check endpoint
        location /health {
            access_log off;
            return 200 "healthy\n";
            add_header Content-Type text/plain;
        }

        # Proxy API requests to backend
        location /api/ {
            proxy_pass http://backend:3000;
            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;
        }

        # Cache static assets
        location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot)$ {
            expires 1y;
            add_header Cache-Control "public, immutable";
            access_log off;
        }

        # SPA routing - serve index.html for all routes
        location / {
            try_files $uri $uri/ /index.html;

            # Don't cache index.html
            add_header Cache-Control "no-cache, no-store, must-revalidate";
            add_header Pragma "no-cache";
            add_header Expires "0";
        }

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

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