/// Parsing + normalization for a flow file's own top-level
/// `project:` key. Kept separate from the page so the "file wins"
/// semantics are unit-testable without pumping the whole editor.
///
/// Mirrors the hub's `resolve_project` (file's `project:` is the
/// run's project unless the caller overrides it) and
/// `normalize_project_slug`, so the chip the editor shows compares
/// equal to what the hub actually stamps.
library;

/// The flow's own top-level `project:` slug (normalized), or empty
/// when the YAML declares none. Only a *non-indented* `project:`
/// line counts — a nested `project:` inside a step's `with:` block
/// is ignored.
String parseFlowProject(String yaml) {
  for (final raw in yaml.split('\n')) {
    if (raw.startsWith(' ') || raw.startsWith('\t')) continue;
    final m = RegExp(r'^project:\s*(.+?)\s*$').firstMatch(raw);
    if (m != null) {
      final value = m.group(1)!.replaceAll(RegExp('''^["']|["']\$'''), '');
      return normalizeProjectSlug(value);
    }
  }
  return '';
}

/// Mirror of the hub's `normalize_project_slug`: lowercase,
/// collapse spaces/underscores/dashes to a single `-`, drop
/// everything else, trim trailing dashes. Empty in → empty out
/// (the editor treats "no project" and "blank project" alike).
String normalizeProjectSlug(String raw) {
  final buf = StringBuffer();
  var prevDash = false;
  for (final ch in raw.trim().toLowerCase().split('')) {
    if (RegExp(r'[a-z0-9]').hasMatch(ch)) {
      buf.write(ch);
      prevDash = false;
    } else if ((ch == ' ' || ch == '_' || ch == '-') &&
        !prevDash &&
        buf.isNotEmpty) {
      buf.write('-');
      prevDash = true;
    }
  }
  var out = buf.toString();
  while (out.endsWith('-')) {
    out = out.substring(0, out.length - 1);
  }
  return out;
}