implemented relativetime input widget

lib/model/alarm/relative_time_alarm.dart

@@ -4,7 +4,7 @@ class RelativeTimeAlarm implements Alarm {
   @override
   final String id;
 
-  final DateTime triggerAt;
+  final Duration triggerAt;
 
   @override
   final AlarmType alarmType;
@@ -15,7 +15,7 @@ class RelativeTimeAlarm implements Alarm {
   factory RelativeTimeAlarm.fromJson(Map<String, dynamic> json) {
     return RelativeTimeAlarm(
       id: json['id'] as String,
-      triggerAt: DateTime.parse(json['triggerAt'] as String),
+      triggerAt: Duration(minutes: json['triggerAt'] as int),
     );
   }
 
@@ -23,7 +23,7 @@ class RelativeTimeAlarm implements Alarm {
   Map<String, dynamic> toJson() {
     return {
       'id': id,
-      'triggerAt': triggerAt.toIso8601String(),
+      'triggerAt': triggerAt.inMinutes,
       'alarmType': alarmType.toJson(),
     };
   }

lib/model/requests/create_relative_time_alarm_request.dart

@@ -3,7 +3,7 @@ import '../alarm/relative_time_alarm.dart';
 import 'create_alarm_request.dart';
 
 class CreateRelativeTimeAlarmRequest extends CreateAlarmRequest {
-  final DateTime? triggerAt;
+  final Duration? triggerAt;
 
   const CreateRelativeTimeAlarmRequest({this.triggerAt})
     : super(alarmType: AlarmType.timeRelative);

lib/pages/task_edit_page.dart

@@ -268,9 +268,8 @@ class _TaskEditPageState extends State<TaskEditPage> {
         alarmRequests.add(CreateLocationAlarmRequest());
       case AlarmType.timeFixed:
         alarmRequests.add(CreateFixedTimeAlarmRequest());
-
       case AlarmType.timeRelative:
-        alarmRequests.add(CreateFixedTimeAlarmRequest());
+        alarmRequests.add(CreateRelativeTimeAlarmRequest());
     }
     setState(() {});
   }

lib/widgets/alarm_widgets/fixed_time_alarm_form.dart

@@ -45,6 +45,7 @@ class _FixedTimeAlarmFormState extends State<FixedTimeAlarmForm> {
   Widget build(BuildContext context) {
     return Flex(
       direction: Axis.horizontal,
+      spacing: AppTheme.formColumnSpacing,
       children: [
         Flexible(
           flex: 3,
@@ -76,9 +77,6 @@ class _FixedTimeAlarmFormState extends State<FixedTimeAlarmForm> {
             textInputAction: TextInputAction.next,
           ),
         ),
-        Padding(
-          padding: EdgeInsetsGeometry.only(left: AppTheme.formColumnSpacing),
-        ),
         Flexible(
           flex: 2,
           child: TextFormField(

lib/widgets/alarm_widgets/relative_time_alarm_form.dart

@@ -1,9 +1,11 @@
 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 StatelessWidget {
+class RelativeTimeAlarmForm extends StatefulWidget {
   const RelativeTimeAlarmForm({
     super.key,
     required this.request,
@@ -12,8 +14,134 @@ class RelativeTimeAlarmForm extends StatelessWidget {
   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 const Placeholder();
+    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 }