/// 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 '';
}

/// The project a flow file effectively belongs to: its own
/// `project:` slug, or `general` when the file declares none.
/// Display/filter semantics only — the FILE stays the truth and
/// is never rewritten to make this explicit.
String effectiveFlowProject(String fileProject) =>
    fileProject.isEmpty ? 'general' : fileProject;

/// Whether a flow file belongs in the list under the active
/// workspace filter. Empty [activeProject] = "all projects";
/// otherwise the file's effective project (no key = `general`)
/// must match.
bool flowVisibleInProject(String fileProject, String activeProject) =>
    activeProject.isEmpty ||
    effectiveFlowProject(fileProject) == activeProject;

/// 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;
}