import 'package:tasq/models/leave_of_absence.model.dart';
import 'package:tasq/models/pass_slip.model.dart';
import 'programmer_daily_time.dart';

/// Index approved leaves covering the given moment by user ID.
///
/// Filters to leaves where:
/// - status == 'approved'
/// - startTime <= now < endTime
///
/// Returns a map from userId to the leave record.
Map<String, LeaveOfAbsence> activeLeaveByUser(
  List<LeaveOfAbsence> leaves,
  DateTime now,
) {
  final result = <String, LeaveOfAbsence>{};
  for (final leave in leaves) {
    if (leave.status == 'approved' &&
        !leave.startTime.isAfter(now) &&
        leave.endTime.isAfter(now)) {
      result[leave.userId] = leave;
    }
  }
  return result;
}

/// Index active pass slips by user ID.
///
/// Filters to slips where slip.isActive is true.
///
/// Returns a map from userId to the pass slip record.
Map<String, PassSlip> activePassSlipByUser(List<PassSlip> slips) {
  final result = <String, PassSlip>{};
  for (final slip in slips) {
    if (slip.isActive) {
      result[slip.userId] = slip;
    }
  }
  return result;
}

/// Get the set of Manila calendar days covered by approved leaves for a user.
///
/// Iterates through all approved leaves for the given user and collects the
/// set of Manila day keys (as DateTime.utc(year, month, day)) from each
/// leave's start date through end date, inclusive.
Set<DateTime> approvedLeaveDays(
  List<LeaveOfAbsence> leaves,
  String userId,
) {
  final result = <DateTime>{};
  for (final leave in leaves) {
    if (leave.userId == userId && leave.status == 'approved') {
      var current = manilaDay(leave.startTime);
      final endDay = manilaDay(leave.endTime);
      while (!current.isAfter(endDay)) {
        result.add(current);
        current = current.add(Duration(days: 1));
      }
    }
  }
  return result;
}