Add pruning mechanism

Author: SebastianZug

prune_pdfs.sh

@@ -0,0 +1,68 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Remove PDFs in assets/**/pdf that are not referenced by any generated HTML
+# Usage: ./prune_pdfs.sh [--dry-run]
+
+DRY_RUN=false
+if [[ ${1-} == "--dry-run" ]]; then
+  DRY_RUN=true
+fi
+
+repo_root="$(cd "$(dirname "$0")" && pwd)"
+cd "$repo_root"
+
+# Collect referenced PDFs from all HTML files
+mapfile -t html_files < <(ls *.html 2>/dev/null || true)
+if [[ ${#html_files[@]} -eq 0 ]]; then
+  echo "No HTML files found; nothing to prune."
+  exit 0
+fi
+
+echo "Scanning HTML files for PDF references..."
+referenced=$(grep -hoE 'assets/[A-Za-z0-9_-]+/pdf/[A-Za-z0-9._-]+\.pdf|assets/pdf/[A-Za-z0-9._-]+\.pdf' -- *.html 2>/dev/null | sort -u || true)
+
+# Normalize to absolute paths
+declare -A keep
+while IFS= read -r rel; do
+  [[ -z "$rel" ]] && continue
+  abs="$repo_root/$rel"
+  keep["$abs"]=1
+done < <(printf "%s\n" "$referenced")
+
+# Find all PDFs under assets/**/pdf
+mapfile -t all_pdfs < <(find assets -type f -name '*.pdf')
+
+# Determine unreferenced PDFs
+unreferenced=()
+for f in "${all_pdfs[@]}"; do
+  if [[ -z ${keep["$repo_root/${f#${repo_root}/}"]+x} && -z ${keep["$f"]+x} ]]; then
+    unreferenced+=("$f")
+  fi
+done
+
+count_total=${#all_pdfs[@]}
+count_keep=${#keep[@]}
+count_delete=${#unreferenced[@]}
+
+echo "Total PDFs: $count_total"
+echo "Referenced PDFs: $count_keep"
+if [[ $count_delete -eq 0 ]]; then
+  echo "No unreferenced PDFs to delete."
+  exit 0
+fi
+
+echo "Unreferenced PDFs to delete ($count_delete):"
+printf " - %s\n" "${unreferenced[@]}"
+
+if $DRY_RUN; then
+  echo "Dry run: not deleting files."
+  exit 0
+fi
+
+echo "Deleting unreferenced PDFs..."
+for f in "${unreferenced[@]}"; do
+  rm -f -- "$f"
+done
+
+echo "Done."