/// Tab enumeration and helpers for the Programmer Tasks list screen.
///
/// This-slice tabs (Task 10):
///   Admin:      [monitor, mine, all]
///   Non-admin:  [mine, all]
///
/// approvals and daySheets are deferred to later slices.
enum ProgrammerTasksTab { monitor, approvals, mine, all, daySheets }

/// Returns the ordered tab list for the current role.
///
/// Admin:      [monitor, approvals, mine, all]
/// Programmer: [mine, all, daySheets]
List<ProgrammerTasksTab> programmerTasksTabsFor({required bool isStrictAdmin}) {
  if (isStrictAdmin) {
    return [
      ProgrammerTasksTab.monitor,
      ProgrammerTasksTab.approvals,
      ProgrammerTasksTab.mine,
      ProgrammerTasksTab.all,
    ];
  }
  return [
    ProgrammerTasksTab.mine,
    ProgrammerTasksTab.all,
    ProgrammerTasksTab.daySheets,
  ];
}

/// Parses a URL query-parameter value to a [ProgrammerTasksTab].
///
/// Valid values: 'monitor', 'approvals', 'mine', 'all', 'day-sheets'.
/// Returns null for unrecognised or null input.
ProgrammerTasksTab? parseProgrammerTasksTab(String? q) {
  switch (q) {
    case 'monitor':
      return ProgrammerTasksTab.monitor;
    case 'approvals':
      return ProgrammerTasksTab.approvals;
    case 'mine':
      return ProgrammerTasksTab.mine;
    case 'all':
      return ProgrammerTasksTab.all;
    case 'day-sheets':
    case 'daySheets':
      return ProgrammerTasksTab.daySheets;
    default:
      return null;
  }
}

/// Human-readable tab label for display in [TabBar].
String programmerTasksTabLabel(ProgrammerTasksTab t) {
  switch (t) {
    case ProgrammerTasksTab.monitor:
      return 'Monitor';
    case ProgrammerTasksTab.approvals:
      return 'Approvals';
    case ProgrammerTasksTab.mine:
      return 'Mine';
    case ProgrammerTasksTab.all:
      return 'All';
    case ProgrammerTasksTab.daySheets:
      return 'Day Sheets';
  }
}