import 'package:fluent_ui/fluent_ui.dart';
import 'package:flutter/material.dart' show ButtonSegment, SegmentedButton;
import 'package:syncfusion_flutter_calendar/calendar.dart' as calendar;
import 'package:task_hub/models/schedule.dart';
import 'package:task_hub/widgets/schedule_dialog.dart';

class AppointmentDataSource extends calendar.CalendarDataSource {
  AppointmentDataSource(List<calendar.Appointment> source) {
    appointments = source;
  }
}

class SchedulePage extends StatefulWidget {
  const SchedulePage({super.key});

  @override
  State<SchedulePage> createState() => _SchedulePageState();
}

class _SchedulePageState extends State<SchedulePage> {
  final calendar.CalendarController _calendarController =
      calendar.CalendarController();
  late List<calendar.Appointment> _appointments = [];
  String _viewType = 'week';

  void _addSchedule(Schedule? schedule) {
    showDialog(
      context: context,
      builder: (context) => ScheduleDialog(
        schedule: schedule,
        onSave: (schedule) {
          setState(() {
            final appointment = calendar.Appointment(
              id: schedule.id,
              subject: schedule.title,
              startTime: schedule.startTime,
              endTime: schedule.endTime,
            );
            _appointments.add(appointment);
          });
        },
      ),
    );
  }

  void _editSchedule(calendar.Appointment appointment) {
    final schedule = Schedule(
      id: appointment.id as int,
      title: appointment.subject,
      startTime: appointment.startTime,
      endTime: appointment.endTime,
    );

    showDialog(
      context: context,
      builder: (context) => ScheduleDialog(
        schedule: schedule,
        onSave: (editedSchedule) {
          setState(() {
            final index = _appointments.indexWhere(
              (t) => t.id == editedSchedule.id,
            );
            if (index != -1) {
              final appointment = calendar.Appointment(
                id: editedSchedule.id,
                subject: editedSchedule.title,
                startTime: editedSchedule.startTime,
                endTime: editedSchedule.endTime,
              );
              _appointments[index] = appointment;
            }
          });
        },
      ),
    );
  }

  void _deleteSchedule(calendar.Appointment appointment) async {
    await showDialog<String>(
      context: context,
      builder: (context) => ContentDialog(
        title: const Text('确认删除该日程？'),
        actions: [
          Button(
            child: const Text('取消'),
            onPressed: () => Navigator.pop(context),
          ),
          FilledButton(
            child: const Text('确认'),
            onPressed: () {
              setState(() {
                _appointments.removeWhere(
                  (schedule) => schedule.id == appointment.id,
                );
              });
              Navigator.pop(context);
              // Delete file here
            },
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return ScaffoldPage.withPadding(
      header: PageHeader(
        title: const Text('日程安排', style: TextStyle(color: Colors.white)),
        commandBar: CommandBar(
          mainAxisAlignment: MainAxisAlignment.end,
          primaryItems: [
            CommandBarButton(
              icon: const Icon(FluentIcons.add, color: Colors.white),
              label: const Text('添加日程', style: TextStyle(color: Colors.white)),
              onPressed: () => _addSchedule(null),
            ),
          ],
        ),
      ),
      content: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            SegmentedButton<String>(
              showSelectedIcon: false,
              selected: <String>{_viewType},
              onSelectionChanged: (Set<String> value) {
                setState(() {
                  _viewType = value.first;
                  switch (_viewType) {
                    case 'week':
                      _calendarController.view = calendar.CalendarView.week;
                      break;
                    case 'month':
                      _calendarController.view = calendar.CalendarView.month;
                      break;
                    case 'schedule':
                      _calendarController.view = calendar.CalendarView.schedule;
                      break;
                  }
                });
              },
              segments: const [
                ButtonSegment(
                  value: 'week',
                  label: Text(
                    '周视图',
                    style: TextStyle(
                      fontFamily: 'CustomFont',
                      color: Colors.white,
                    ),
                  ),
                ),
                ButtonSegment(
                  value: 'month',
                  label: Text(
                    '月视图',
                    style: TextStyle(
                      fontFamily: 'CustomFont',
                      color: Colors.white,
                    ),
                  ),
                ),
                ButtonSegment(
                  value: 'schedule',
                  label: Text(
                    '日程视图',
                    style: TextStyle(
                      fontFamily: 'CustomFont',
                      color: Colors.white,
                    ),
                  ),
                ),
              ],
            ),
            const SizedBox(height: 20),
            Expanded(child: Card(child: _buildSfCalendar())),
          ],
        ),
      ),
    );
  }

  Widget _buildSfCalendar() {
    return calendar.SfCalendar(
      view: calendar.CalendarView.week,
      controller: _calendarController,
      backgroundColor: Colors.grey[20],
      headerStyle: calendar.CalendarHeaderStyle(
        backgroundColor: Colors.grey[20],
      ),
      dataSource: AppointmentDataSource(_appointments),
      firstDayOfWeek: 1,
      showDatePickerButton: true,
      showNavigationArrow: true,
      showTodayButton: true,
      allowViewNavigation: true,
      // 月份视图设置
      monthViewSettings: calendar.MonthViewSettings(
        appointmentDisplayMode:
            calendar.MonthAppointmentDisplayMode.appointment,
        showAgenda: true,
      ),
      scheduleViewSettings: calendar.ScheduleViewSettings(
        monthHeaderSettings: calendar.MonthHeaderSettings(
          backgroundColor: Colors.grey[20],
          height: 85,
        ),
      ),
      // 时间区域设置
      timeSlotViewSettings: calendar.TimeSlotViewSettings(
        startHour: 7,
        endHour: 23,
        timeFormat: 'HH:mm',
        timeInterval: Duration(minutes: 30),
        timeRulerSize: 60,
      ),
      // 选择日期回调
      onTap: (calendar.CalendarTapDetails details) {
        if (_calendarController.view == calendar.CalendarView.week) {
          if (details.targetElement == calendar.CalendarElement.calendarCell) {
            if (!details.date!.isBefore(DateTime.now())) {
              final schedule = Schedule(
                title: '',
                startTime: details.date!,
                endTime: details.date!.add(Duration(minutes: 30)),
              );
              _addSchedule(schedule);
            }
          } else if (details.targetElement ==
              calendar.CalendarElement.appointment) {
            if (details.appointments?.length == 1) {
              _editSchedule(details.appointments!.first);
            }
          }
        }
      },
      // 选择日程回调
      onLongPress: (calendar.CalendarLongPressDetails details) async {
        if (details.targetElement == calendar.CalendarElement.appointment) {
          if (details.appointments?.length == 1) {
            _deleteSchedule(details.appointments!.first);
          }
        }
      },
    );
  }
}