#!/usr/bin/env bash
# Injects mermaid.js script into HTML files that contain mermaid code blocks.
# Usage: inject-mermaid.sh <html_directory>

HTML_DIR="${1:-.}"

inject_mermaid() {
  local html_file="$1"
  python3 - "$html_file" << 'PYEOF'
import sys

path = sys.argv[1]
snippet = """\
<script type="module">
import mermaid from 'https://cdn.jsdelivr.net/npm/mermaid@11/dist/mermaid.esm.min.mjs';
document.querySelectorAll('code.language-mermaid').forEach(el => {
  const div = document.createElement('div');
  div.className = 'mermaid';
  div.textContent = el.textContent;
  el.closest('pre').replaceWith(div);
});
mermaid.initialize({ startOnLoad: true, theme: 'dark' });
</script>"""

with open(path, encoding='utf-8') as f:
    content = f.read()

# Skip if already injected
if 'mermaid.esm' in content:
    sys.exit(0)

# Skip if no mermaid blocks
if 'language-mermaid' not in content:
    sys.exit(0)

new_content = content.replace('</body>', snippet + '\n</body>', 1)
if new_content == content:
    print(f"Warning: </body> not found in {path}", file=sys.stderr)
    sys.exit(1)

with open(path, 'w', encoding='utf-8') as f:
    f.write(new_content)
PYEOF
}

# Find and process all HTML files in the directory
if command -v python3 &>/dev/null; then
  for html_file in "$HTML_DIR"/*.html; do
    [ -f "$html_file" ] || continue
    [ "$(basename "$html_file")" = "index.html" ] && continue

    if grep -q 'language-mermaid' "$html_file" 2>/dev/null; then
      if ! grep -q 'mermaid.esm' "$html_file" 2>/dev/null; then
        inject_mermaid "$html_file" && echo "  Injected mermaid.js into $(basename "$html_file")"
      fi
    fi
  done
else
  echo "Warning: python3 not found — skipping mermaid injection"
  exit 1
fi