# Use $request_id as a pseudo-nonce for Content Security Policy (CSP)
# $request_id is unique per request and will serve as a nonce value here.

# Map $request_id to a variable named $nonce
map $request_id $nonce {
    default "$request_id";
}

server {
    listen 8080;
    root /usr/share/nginx/html;
    index resume.html;

    # Security headers
    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
    add_header Permissions-Policy "camera=(), microphone=(), geolocation=(), accelerometer=(), gyroscope=(), magnetometer=(), payment=(), usb=()" always;

    # Content Security Policy (CSP) with injected $nonce for script-src
    # Allows inline scripts that match the nonce generated for each request
    add_header Content-Security-Policy "default-src 'none'; script-src 'self' 'nonce-$nonce' https://matomo.nixc.us; style-src 'self' 'unsafe-inline' https://colinknapp.com; img-src 'self' https://matomo.nixc.us https://colinknapp.com https://hedgedoc.nixc.us; font-src 'self' data:; frame-ancestors 'self'; base-uri 'self'; form-action 'self';" always;

    # Cross-origin isolation headers
    add_header Cross-Origin-Embedder-Policy "require-corp" always;
    add_header Cross-Origin-Resource-Policy "same-origin" always;
    add_header Cross-Origin-Opener-Policy "same-origin" always;

    # Use sub_filter to inject the nonce into inline <script> tags automatically
    # This works for HTML responses where <script> tags are inline in the HTML
    sub_filter '<script>' '<script nonce="$nonce">';
    sub_filter_once off; # Apply the replacement to all instances of <script> tags
    sub_filter_types text/html; # Only apply the sub_filter to HTML content

    # Redirect demo.hedgedoc.org resources to hedgedoc.nixc.us for compatibility
    sub_filter "https://demo.hedgedoc.org" "https://hedgedoc.nixc.us";

    location / {
        try_files $uri $uri/ =404;
    }
}
