import 'package:flutter_test/flutter_test.dart';
import 'package:marianum_mobile/api/mhsl/custom_timetable_event/custom_timetable_event.dart';
import 'package:marianum_mobile/api/mhsl/custom_timetable_event/get/get_custom_timetable_event_response.dart';
import 'package:marianum_mobile/api/webuntis/queries/get_holidays/get_holidays_response.dart';
import 'package:marianum_mobile/api/webuntis/queries/get_timetable/get_timetable_response.dart';
import 'package:marianum_mobile/widget_data/widget_data.dart';
import 'package:marianum_mobile/widget_data/widget_data_mapper.dart';

CustomTimetableEvent _event({
  required String id,
  required String title,
  required DateTime start,
  required DateTime end,
}) => CustomTimetableEvent(
  id: id,
  title: title,
  description: '',
  startDate: start,
  endDate: end,
  color: 'orange',
  rrule: '',
  createdAt: start,
  updatedAt: start,
);

GetTimetableResponseObject _lesson({
  required int date,
  required int startTime,
  required int endTime,
  String? code,
  String? subjectName,
  String? room,
  int teacherId = 1,
  String? teacherName,
  String? teacherOrgname,
  String? substText,
}) => GetTimetableResponseObject(
  id: 1,
  date: date,
  startTime: startTime,
  endTime: endTime,
  code: code,
  substText: substText,
  kl: const [],
  te: teacherName != null
      ? [
          GetTimetableResponseObjectTeacher(
            teacherId,
            teacherName,
            teacherName,
            teacherOrgname == null ? null : 9,
            teacherOrgname,
            null,
          ),
        ]
      : const [],
  su: subjectName != null
      ? [
          GetTimetableResponseObjectSubject(
            5,
            subjectName,
            subjectName,
          ),
        ]
      : const [],
  ro: room != null
      ? [GetTimetableResponseObjectRoom(7, room, room)]
      : const [],
);

void main() {
  group('resolveDayAnchor', () {
    test('weekday before cutoff stays today', () {
      final anchor = WidgetDataMapper.resolveDayAnchor(
        DateTime(2026, 5, 6, 10),
      );
      expect(anchor, DateTime(2026, 5, 6));
    });

    test('weekday after cutoff jumps to next school day', () {
      final anchor = WidgetDataMapper.resolveDayAnchor(
        DateTime(2026, 5, 6, 19),
      );
      expect(anchor, DateTime(2026, 5, 7));
    });

    test('Friday after cutoff jumps to Monday', () {
      final anchor = WidgetDataMapper.resolveDayAnchor(
        DateTime(2026, 5, 8, 18),
      );
      expect(anchor, DateTime(2026, 5, 11));
    });

    test('Saturday morning jumps to Monday', () {
      final anchor = WidgetDataMapper.resolveDayAnchor(
        DateTime(2026, 5, 9, 10),
      );
      expect(anchor, DateTime(2026, 5, 11));
    });

    test('Sunday evening jumps to Monday', () {
      final anchor = WidgetDataMapper.resolveDayAnchor(
        DateTime(2026, 5, 10, 22),
      );
      expect(anchor, DateTime(2026, 5, 11));
    });
  });

  group('resolveWeekAnchor', () {
    test('Tuesday returns the Monday of that week', () {
      final anchor = WidgetDataMapper.resolveWeekAnchor(
        DateTime(2026, 5, 5, 10),
      );
      expect(anchor, DateTime(2026, 5, 4));
    });

    test('Sunday returns next Monday', () {
      final anchor = WidgetDataMapper.resolveWeekAnchor(
        DateTime(2026, 5, 10, 10),
      );
      expect(anchor, DateTime(2026, 5, 11));
    });
  });

  group('buildDayData', () {
    final now = DateTime(2026, 5, 6, 10);

    test('only includes lessons on the anchor day', () {
      final lessons = [
        _lesson(date: 20260506, startTime: 800, endTime: 845, subjectName: 'MA'),
        _lesson(date: 20260507, startTime: 800, endTime: 845, subjectName: 'EN'),
      ];
      final data = WidgetDataMapper.buildDayData(
        now: now,
        lessons: lessons,
        subjects: null,
        rooms: null,
        holidays: null,
      );
      expect(data.lessons, hasLength(1));
      expect(data.lessons.first.subjectShort, 'MA');
    });

    test('classifies cancelled and irregular lessons', () {
      final lessons = [
        _lesson(
          date: 20260506,
          startTime: 800,
          endTime: 845,
          subjectName: 'MA',
          code: 'cancelled',
        ),
        _lesson(
          date: 20260506,
          startTime: 900,
          endTime: 945,
          subjectName: 'EN',
          code: 'irregular',
        ),
        _lesson(
          date: 20260506,
          startTime: 1000,
          endTime: 1045,
          subjectName: 'BIO',
          teacherName: 'Müller',
          teacherOrgname: 'Schmidt',
        ),
      ];
      final data = WidgetDataMapper.buildDayData(
        now: now,
        lessons: lessons,
        subjects: null,
        rooms: null,
        holidays: null,
      );
      expect(
        data.lessons.map((l) => l.status).toList(),
        [
          WidgetLessonStatus.cancelled,
          WidgetLessonStatus.irregular,
          WidgetLessonStatus.teacherChanged,
        ],
      );
    });

    test('marks day as holiday when in holiday range', () {
      final holidays = GetHolidaysResponse({
        GetHolidaysResponseObject(
          1,
          'Pfingsten',
          'Pfingstferien',
          20260506,
          20260510,
        ),
      });
      final data = WidgetDataMapper.buildDayData(
        now: now,
        lessons: const [],
        subjects: null,
        rooms: null,
        holidays: holidays,
      );
      expect(data.isHoliday, isTrue);
      expect(data.holidayName, 'Pfingstferien');
    });

    test('lessons are sorted by start time', () {
      final lessons = [
        _lesson(
          date: 20260506,
          startTime: 1000,
          endTime: 1045,
          subjectName: 'BIO',
        ),
        _lesson(
          date: 20260506,
          startTime: 800,
          endTime: 845,
          subjectName: 'MA',
        ),
        _lesson(
          date: 20260506,
          startTime: 900,
          endTime: 945,
          subjectName: 'EN',
        ),
      ];
      final data = WidgetDataMapper.buildDayData(
        now: now,
        lessons: lessons,
        subjects: null,
        rooms: null,
        holidays: null,
      );
      expect(
        data.lessons.map((l) => l.subjectShort).toList(),
        ['MA', 'EN', 'BIO'],
      );
    });
  });

  group('event collision bumping', () {
    final now = DateTime(2026, 5, 6, 10);

    test('long event bumps every regular lesson it covers', () {
      final lessons = [
        _lesson(date: 20260506, startTime: 800, endTime: 845, subjectName: 'MA'),
        _lesson(date: 20260506, startTime: 900, endTime: 945, subjectName: 'EN'),
        _lesson(date: 20260506, startTime: 1000, endTime: 1045, subjectName: 'BIO'),
      ];
      final events = GetCustomTimetableEventResponse([
        _event(
          id: 'a',
          title: 'Wandertag',
          start: DateTime(2026, 5, 6, 8),
          end: DateTime(2026, 5, 6, 11),
        ),
      ]);
      final data = WidgetDataMapper.buildDayData(
        now: now,
        lessons: lessons,
        subjects: null,
        rooms: null,
        holidays: null,
        customEvents: events,
      );
      expect(data.lessons, hasLength(3));
      for (final l in data.lessons) {
        expect(l.siblingCount, 1, reason: '${l.subjectShort} should be bumped');
      }
    });

    test('event + same-slot duplicate regular: kept lesson shows +2', () {
      // User scenario: a long custom event covers the slot, and Webuntis
      // reports two regular lessons starting at the same time (different
      // class group). The user wants "+2" — one for the hidden event, one
      // for the parallel regular lesson — not just "+1".
      final lessons = [
        _lesson(date: 20260506, startTime: 900, endTime: 945, subjectName: 'EN'),
        _lesson(date: 20260506, startTime: 900, endTime: 945, subjectName: 'MA'),
      ];
      final events = GetCustomTimetableEventResponse([
        _event(
          id: 'long',
          title: 'Wandertag',
          start: DateTime(2026, 5, 6, 8),
          end: DateTime(2026, 5, 6, 12),
        ),
      ]);
      final data = WidgetDataMapper.buildDayData(
        now: now,
        lessons: lessons,
        subjects: null,
        rooms: null,
        holidays: null,
        customEvents: events,
      );
      expect(data.lessons, hasLength(1));
      expect(data.lessons.first.siblingCount, 2);
    });

    test('multi-day event splits into one block per calendar day', () {
      final events = GetCustomTimetableEventResponse([
        _event(
          id: 'multi',
          title: 'Klassenfahrt',
          start: DateTime(2026, 5, 4, 8),
          end: DateTime(2026, 5, 6, 14),
        ),
      ]);
      final data = WidgetDataMapper.buildWeekData(
        now: DateTime(2026, 5, 5, 10),
        lessons: const [],
        subjects: null,
        rooms: null,
        holidays: null,
        customEvents: events,
      );
      expect(data.lessons, hasLength(3));
      expect(data.lessons[0].start, DateTime(2026, 5, 4, 8));
      expect(data.lessons[0].end, DateTime(2026, 5, 4, 23, 59));
      expect(data.lessons[1].start, DateTime(2026, 5, 5, 0));
      expect(data.lessons[1].end, DateTime(2026, 5, 5, 23, 59));
      expect(data.lessons[2].start, DateTime(2026, 5, 6, 0));
      expect(data.lessons[2].end, DateTime(2026, 5, 6, 14));
    });

    test('two events covering the same regular lesson bump it twice', () {
      final lessons = [
        _lesson(date: 20260506, startTime: 900, endTime: 945, subjectName: 'EN'),
      ];
      final events = GetCustomTimetableEventResponse([
        _event(
          id: 'long',
          title: 'Termin lang',
          start: DateTime(2026, 5, 6, 8),
          end: DateTime(2026, 5, 6, 12),
        ),
        _event(
          id: 'short',
          title: 'Termin kurz',
          start: DateTime(2026, 5, 6, 9),
          end: DateTime(2026, 5, 6, 10),
        ),
      ]);
      final data = WidgetDataMapper.buildDayData(
        now: now,
        lessons: lessons,
        subjects: null,
        rooms: null,
        holidays: null,
        customEvents: events,
      );
      expect(data.lessons, hasLength(1));
      expect(data.lessons.first.subjectShort, 'EN');
      expect(data.lessons.first.siblingCount, 2);
    });
  });

  group('buildWeekData', () {
    final now = DateTime(2026, 5, 5, 10); // Tuesday

    test('contains lessons across the school week', () {
      final lessons = [
        _lesson(date: 20260504, startTime: 800, endTime: 845, subjectName: 'MO'),
        _lesson(date: 20260506, startTime: 800, endTime: 845, subjectName: 'WE'),
        _lesson(date: 20260508, startTime: 800, endTime: 845, subjectName: 'FR'),
        _lesson(date: 20260511, startTime: 800, endTime: 845, subjectName: 'NEXT'),
      ];
      final data = WidgetDataMapper.buildWeekData(
        now: now,
        lessons: lessons,
        subjects: null,
        rooms: null,
        holidays: null,
      );
      // Anchor is Mon 04.05.; week ends Fri 08.05. exclusive of next Mon
      expect(data.anchorDate, DateTime(2026, 5, 4));
      expect(
        data.lessons.map((l) => l.subjectShort).toList(),
        ['MO', 'WE', 'FR'],
      );
    });
  });
}