import 'dart:ui' show FontFeature;
import 'package:flutter/material.dart';

import '../models/work_day.dart';

String monthTitle(DateTime m) {
  const months = [
    'Januar', 'Februar', 'März', 'April', 'Mai', 'Juni',
    'Juli', 'August', 'September', 'Oktober', 'November', 'Dezember'
  ];
  return '${months[m.month - 1]} ${m.year}';
}

String leftDayLabel(DateTime d) => '${ddmm(d)} ${weekdayShort(d)}';
String rightDayLabel(DateTime d) => '${weekdayShort(d)} ${ddmm(d)}';

String weekdayShort(DateTime d) {
  switch (d.weekday) {
    case DateTime.monday: return 'Mo';
    case DateTime.tuesday: return 'Di';
    case DateTime.wednesday: return 'Mi';
    case DateTime.thursday: return 'Do';
    case DateTime.friday: return 'Fr';
    case DateTime.saturday: return 'Sa';
    case DateTime.sunday: return 'So';
    default: return '';
  }
}

String ddmm(DateTime d) =>
    '${d.day.toString().padLeft(2, '0')}.${d.month.toString().padLeft(2, '0')}';

Widget mono(String s) =>
    Text(s, style: const TextStyle(fontFeatures: [FontFeature.tabularFigures()]));

String fmtTimeOfDay(TimeOfDay t) =>
    '${t.hour.toString().padLeft(2, '0')}:${t.minute.toString().padLeft(2, '0')}';

String minutesToHHMM(int minutes) {
  final h = minutes ~/ 60;
  final m = minutes % 60;
  return '${h.toString().padLeft(2, '0')}:${m.toString().padLeft(2, '0')}';
}

String minutesToSignedHHMM(int minutes) {
  final sign = minutes < 0 ? '-' : '+';
  final absMin = minutes.abs();
  final h = absMin ~/ 60;
  final m = absMin % 60;
  return '$sign${h.toString().padLeft(2, '0')}:${m.toString().padLeft(2, '0')}';
}

TimeOfDay? parseHHMM(dynamic v) {
  if (v == null) return null;
  final s = v.toString().trim();
  if (s.isEmpty) return null;
  final parts = s.split(':');
  if (parts.length < 2) return null;
  final h = int.tryParse(parts[0]) ?? 0;
  final m = int.tryParse(parts[1]) ?? 0;
  if (h < 0 || h > 23 || m < 0 || m > 59) return null;
  return TimeOfDay(hour: h, minute: m);
}

TimeOfDay? parseTextHHMM(String s) {
  final t = s.trim();
  if (t.length != 5 || t[2] != ':') return null;
  final h = int.tryParse(t.substring(0, 2));
  final m = int.tryParse(t.substring(3, 5));
  if (h == null || m == null) return null;
  if (h < 0 || h > 23 || m < 0 || m > 59) return null;
  return TimeOfDay(hour: h, minute: m);
}

String ymd(DateTime d) =>
    '${d.year.toString().padLeft(4, '0')}-${d.month.toString().padLeft(2, '0')}-${d.day.toString().padLeft(2, '0')}';

// Füllt alle Tage des Monats auf
List<WorkDay> fillMonth(DateTime monthStart, List<WorkDay> existing) {
  final map = <String, WorkDay>{for (final w in existing) ymd(w.date): w};
  final nextMonth = DateTime(monthStart.year, monthStart.month + 1, 1);
  final out = <WorkDay>[];
  for (DateTime d = monthStart; d.isBefore(nextMonth); d = d.add(const Duration(days: 1))) {
    final key = ymd(d);
    final wd = map[key];
    if (wd != null) {
      out.add(wd);
    } else {
      final isWeekend = d.weekday == DateTime.saturday || d.weekday == DateTime.sunday;
      final target = isWeekend ? 0 : 8 * 60;
      out.add(WorkDay(date: d, intervals: const [], targetMinutes: target));
    }
  }
  return out;
}

/// "HH:MM:SS" → Minuten (Sekunden ignoriert). Ungültig => null.
int? minutesFromHHMMSS(String? s) {
  if (s == null) return null;
  final parts = s.split(':');
  if (parts.length != 3) return null;
  final h = int.tryParse(parts[0]) ?? 0;
  final m = int.tryParse(parts[1]) ?? 0;
  return h * 60 + m;
}

// Abwesenheitscodes und Labels
const List<String> kAbsenceCodes = ['GZ', 'K', 'U', 'SU', 'T'];

String codeLabel(String? code) {
  switch (code) {
    case 'GZ': return 'Gleitzeit';
    case 'K':  return 'Krankenstand';
    case 'U':  return 'Urlaub';
    case 'SU': return 'Sonderurlaub';
    case 'T':  return 'Training';
    default:   return '—';
  }
}