import 'package:flutter/material.dart';

import '../../app_theme.dart';
import '../../model/requests/create_alarm_request.dart';
import '../../model/requests/create_relative_time_alarm_request.dart';
import '../../service/validators.dart';

class RelativeTimeAlarmForm extends StatefulWidget {
  const RelativeTimeAlarmForm({
    super.key,
    required this.request,
    required this.onChanged,
  });
  final CreateRelativeTimeAlarmRequest request;
  final ValueChanged<CreateAlarmRequest> onChanged;

  @override
  State<RelativeTimeAlarmForm> createState() => _RelativeTimeAlarmFormState();
}

class _RelativeTimeAlarmFormState extends State<RelativeTimeAlarmForm> {
  final timeController = TextEditingController();

  static const List<DropdownMenuEntry<TimeUnit>> timeUnitOptions = [
    DropdownMenuEntry<TimeUnit>(value: TimeUnit.minute, label: 'Minutes'),
    DropdownMenuEntry<TimeUnit>(value: TimeUnit.hour, label: 'Hours'),
    DropdownMenuEntry<TimeUnit>(value: TimeUnit.day, label: 'Days'),
  ];

  static const List<DropdownMenuEntry<TimeRelation>> timeRelationOptions = [
    DropdownMenuEntry<TimeRelation>(
      value: TimeRelation.before,
      label: 'Before',
    ),
    DropdownMenuEntry<TimeRelation>(value: TimeRelation.after, label: 'After'),
  ];

  late TimeUnit selectedTimeUnit;
  late TimeRelation selectedTimeRelation;

  @override
  void initState() {
    super.initState();

    if (widget.request.triggerAt == null) {
      selectedTimeUnit = TimeUnit.minute;
      selectedTimeRelation = TimeRelation.before;
      return;
    }

    final duration = widget.request.triggerAt!;

    selectedTimeRelation = duration.isNegative
        ? TimeRelation.before
        : TimeRelation.after;

    final absDuration = duration.abs();

    if (absDuration.inMinutes <= 99 && absDuration.inMinutes % 60 != 0) {
      selectedTimeUnit = TimeUnit.minute;
      timeController.text = absDuration.inMinutes.toString();
    } else if (absDuration.inHours <= 99 && absDuration.inHours % 24 != 0) {
      selectedTimeUnit = TimeUnit.hour;
      timeController.text = absDuration.inHours.toString();
    } else {
      selectedTimeUnit = TimeUnit.day;
      timeController.text = absDuration.inDays.toString();
    }
  }

  @override
  Widget build(BuildContext context) {
    return Flex(
      direction: Axis.horizontal,
      spacing: AppTheme.formColumnSpacing,
      children: [
        Flexible(
          flex: 7,
          child: TextFormField(
            controller: timeController,
            maxLength: 2,
            onChanged: onTimeChanged,
            validator: (value) =>
                notEmptyValidator(value) ?? wholeNumberValidator(value),
            keyboardType: TextInputType.number,
            textInputAction: TextInputAction.next,
            decoration: InputDecoration(label: Text('Time'), counterText: ''),
          ),
        ),
        Flexible(
          flex: 10,
          child: DropdownMenuFormField<TimeUnit>(
            dropdownMenuEntries: timeUnitOptions,
            initialSelection: selectedTimeUnit,
            showTrailingIcon: false,
            onSelected: (value) {
              selectedTimeUnit = value!;
              onTimeChanged(timeController.text);
            },
          ),
        ),
        Flexible(
          flex: 10,
          child: DropdownMenuFormField<TimeRelation>(
            dropdownMenuEntries: timeRelationOptions,
            initialSelection: selectedTimeRelation,
            showTrailingIcon: false,
            onSelected: (value) {
              selectedTimeRelation = value!;
              onTimeChanged(timeController.text);
            },
          ),
        ),
      ],
    );
  }

  void onTimeChanged(String value) {
    int? time = int.tryParse(value);
    if (wholeNumberValidator(value) != null || time == null) return;
    Duration duration;
    int signedTime = selectedTimeRelation.apply(time);

    switch (selectedTimeUnit) {
      case TimeUnit.minute:
        duration = Duration(minutes: signedTime);
      case TimeUnit.hour:
        duration = Duration(hours: signedTime);
      case TimeUnit.day:
        duration = Duration(days: signedTime);
    }

    widget.onChanged(CreateRelativeTimeAlarmRequest(triggerAt: duration));
  }
}

enum TimeRelation {
  before,
  after;

  int apply(int value) => switch (this) {
    TimeRelation.before => -value,
    TimeRelation.after => value,
  };
}

enum TimeUnit { minute, hour, day }