server {
    listen 80;
    server_name localhost;

    client_max_body_size 100M;

    root /usr/share/nginx/html;
    index index.html;

    include /etc/nginx/mime.types;

    # Gzip compression
    gzip on;
    gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;

    # Priority prefix location for uploads - proxies to Express backend container
    location ^~ /uploads/ {
        proxy_pass http://backend:3005/uploads/;
        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;

        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
    }

    # Priority prefix location for backend API
    location ^~ /api/ {
        proxy_pass http://backend:3005/api/;
        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;
        proxy_set_header X-Forwarded-Proto $scheme;

        # Prevent 504 Gateway Timeouts
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
    }

    # Explicit handling for static JS, CSS, images, and fonts
    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot|map)$ {
        try_files $uri /citpl_website$uri =404;
        expires 30d;
        add_header Cache-Control "public, no-transform";
    }

    # Handle React SPA routing for main site
    location / {
        try_files $uri $uri/ /index.html;
    }

    # Support /citpl_website/ prefix routing
    location /citpl_website/ {
        alias /usr/share/nginx/html/;
        try_files $uri $uri/ /index.html;
    }

    # Handle Admin SPA routing
    location /admin {
        try_files $uri $uri/ /admin.html;
    }

    # Handle Preview SPA routing
    location /preview {
        try_files $uri $uri/ /preview.html;
    }

    error_page 500 502 503 504 /50x.html;
    location = /50x.html {
        root /usr/share/nginx/html;
    }
}