import 'package:flutter/material.dart';

import '../service/tools.dart' show getIsoDateString;
import '../service/validators.dart';

class TimeSelector extends StatefulWidget {
  const TimeSelector({
    super.key,
    this.initialDueDateTime,
    this.nextFocusNode,
    required this.dueDateController,
    required this.dueTimeController,
    this.formKey,
  });

  final DateTime? initialDueDateTime;
  final GlobalKey<FormState>? formKey;
  final FocusNode? nextFocusNode;
  final TextEditingController dueDateController;
  final TextEditingController dueTimeController;

  @override
  State<TimeSelector> createState() => _TimeSelectorState();
}

class _TimeSelectorState extends State<TimeSelector> {
  final dueDateFocusNode = FocusNode();

  final dueTimeFocusNode = FocusNode();

  bool isDueTimeEnabled = false;

  @override
  void initState() {
    isDueTimeEnabled = widget.initialDueDateTime != null;
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Flex(
      direction: Axis.horizontal,

      children: [
        Flexible(
          flex: 3,
          child: TextFormField(
            focusNode: dueDateFocusNode,
            controller: widget.dueDateController,
            onChanged: maybeEnableDueTime,
            onFieldSubmitted: (_) {
              isDueTimeEnabled
                  ? dueDateFocusNode.nextFocus()
                  : widget.nextFocusNode?.requestFocus();
            },
            decoration: InputDecoration(
              label: Text('Due Date'),
              suffixIcon: IconButton(
                onPressed: () async {
                  final result = await onOpenCalendarPickerPressed();
                  if (result != null) {
                    final dateString = getIsoDateString(result);
                    widget.dueDateController.text = dateString;
                    maybeEnableDueTime(dateString);
                    widget.formKey?.currentState?.validate();
                    dueTimeFocusNode.requestFocus();
                  }
                },
                icon: Icon(Icons.calendar_month),
              ),
            ),
            validator: dateTimeValidator,
            keyboardType: TextInputType.datetime,
            textInputAction: TextInputAction.next,
          ),
        ),
        Padding(padding: EdgeInsetsGeometry.only(left: 10)),
        Flexible(
          flex: 2,
          child: TextFormField(
            focusNode: dueTimeFocusNode,
            onFieldSubmitted: (_) => dueTimeFocusNode.nextFocus(),
            controller: widget.dueTimeController,
            enabled: isDueTimeEnabled,
            decoration: InputDecoration(
              label: Text('Due Time'),
              suffixIcon: IconButton(
                onPressed: () async {
                  final result = await onOpenTimePickerPressed();
                  if (result != null && context.mounted) {
                    widget.dueTimeController.text = result.format(context);
                    widget.nextFocusNode?.requestFocus();
                  }
                },
                icon: Icon(Icons.schedule),
              ),
            ),
            validator: timeValidator,
            keyboardType: TextInputType.text,
            textInputAction: TextInputAction.next,
          ),
        ),
      ],
    );
  }

  Future<DateTime?> onOpenCalendarPickerPressed() {
    return showDialog<DateTime?>(
      context: context,
      builder: (context) => DatePickerDialog(
        firstDate: DateTime(DateTime.now().year - 100),
        lastDate: DateTime(DateTime.now().year + 100),
        initialDate:
            DateTime.tryParse(widget.dueDateController.text) ?? DateTime.now(),
      ),
    );
  }

  Future<TimeOfDay?> onOpenTimePickerPressed() {
    return showDialog<TimeOfDay?>(
      context: context,
      builder: (context) => TimePickerDialog(
        initialTime: TimeOfDay.fromDateTime(
          widget.initialDueDateTime ?? DateTime.now(),
        ),
      ),
    );
  }

  void maybeEnableDueTime(String value) {
    if (value.isNotEmpty && dateTimeValidator(value) == null) {
      setState(() {
        isDueTimeEnabled = true;
      });
    } else if (isDueTimeEnabled) {
      setState(() {
        isDueTimeEnabled = false;
      });
    }
  }
}