import 'package:diameter/components/detail.dart';
import 'package:diameter/components/dialogs.dart';
import 'package:diameter/config.dart';
import 'package:diameter/navigation.dart';
import 'package:diameter/utils/date_time_utils.dart';
import 'package:flutter/material.dart';
import 'package:diameter/components/forms.dart';
import 'package:diameter/models/basal.dart';
import 'package:diameter/models/basal_profile.dart';

class BasalDetailScreen extends StatefulWidget {
  static const String routeName = '/basal';

  final int basalProfileId;
  final int id;
  final TimeOfDay? suggestedStartTime;
  final TimeOfDay? suggestedEndTime;

  const BasalDetailScreen(
      {Key? key,
      this.basalProfileId = 0,
      this.id = 0,
      this.suggestedStartTime,
      this.suggestedEndTime})
      : super(key: key);

  @override
  _BasalDetailScreenState createState() => _BasalDetailScreenState();
}

class _BasalDetailScreenState extends State<BasalDetailScreen> {
  Basal? _basal;
  bool _isNew = true;
  bool _isSaving = false;

  final GlobalKey<FormState> _basalForm = GlobalKey<FormState>();

  TimeOfDay _startTime = const TimeOfDay(hour: 0, minute: 0);
  TimeOfDay _endTime = const TimeOfDay(hour: 0, minute: 0);

  final _startTimeController = TextEditingController(text: '');
  final _endTimeController = TextEditingController(text: '');
  final _unitsController = TextEditingController(text: '');

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

    if (widget.suggestedStartTime != null) {
      _startTime = widget.suggestedStartTime!;
    }
    if (widget.suggestedEndTime != null) {
      _endTime = widget.suggestedEndTime!;
    }

    if (_basal != null) {
      _startTime = TimeOfDay.fromDateTime(_basal!.startTime);
      _endTime = TimeOfDay.fromDateTime(_basal!.endTime);
      _unitsController.text = _basal!.units.toString();
    }

    updateStartTime();
    updateEndTime();
  }

  void reload() {
    if (widget.id != 0) {
      setState(() {
        _basal = Basal.get(widget.id);
      });
    }
    _isNew = _basal == null;
  }

  void updateStartTime() {
    _startTimeController.text = DateTimeUtils.displayTimeOfDay(_startTime);
  }

  void updateEndTime() {
    _endTimeController.text = DateTimeUtils.displayTimeOfDay(_endTime);
  }

  Future<String?> validateTimePeriod() async {
    String? error;
    List<Basal> basalRates = Basal.getAllForProfile(widget.basalProfileId);

    // TODO use a query for the following checks instead?
    // check for duplicates
    if (basalRates
        .where((other) =>
            (widget.id != other.id) &&
            _startTime.hour == other.startTime.hour &&
            _startTime.minute == other.startTime.minute)
        .isNotEmpty) {
      error = 'There\'s already a rate with this start time.';
    }

    if (basalRates
        .where((other) =>
            (widget.id != other.id) &&
            DateTimeUtils.convertTimeOfDayToDateTime(_startTime)
                .isBefore(other.startTime) &&
            DateTimeUtils.convertTimeOfDayToDateTime(_endTime)
                .isAfter(other.startTime))
        .isNotEmpty) {
      error = 'This rate\'s time period overlaps with another one.';
    }

    return error == null
        ? null
        : showDialog(
            context: context,
            builder: (BuildContext context) {
              return AlertDialog(
                content: Text(error!),
                actions: <Widget>[
                  TextButton(
                    onPressed: () => Navigator.pop(context, 'CANCEL'),
                    child: const Text('GO BACK TO EDITING'),
                  ),
                  ElevatedButton(
                    onPressed: () => Navigator.pop(context, 'CONFIRM'),
                    child: const Text('SAVE AS IS'),
                  ),
                ],
              );
            });
  }

  void handleSaveAction() async {
    setState(() {
      _isSaving = true;
    });
    if (_basalForm.currentState!.validate()) {
      await validateTimePeriod().then((value) async {
        if (value != 'CANCEL') {
          Basal basal = Basal(
            id: widget.id,
            startTime: DateTimeUtils.convertTimeOfDayToDateTime(_startTime),
            endTime: DateTimeUtils.convertTimeOfDayToDateTime(_endTime),
            units: double.parse(_unitsController.text),
          );
          basal.basalProfile.targetId = widget.basalProfileId;
          Basal.put(basal);
          Navigator.pop(context, '${_isNew ? 'New' : ''} Basal Rate saved');
        }
      });
    }
    setState(() {
      _isSaving = false;
    });
  }

  void handleCancelAction() {
    if (showConfirmationDialogOnCancel &&
        ((_isNew &&
                (_startTime.hour != (widget.suggestedStartTime?.hour ?? 0) ||
                    _endTime.hour != (widget.suggestedEndTime?.hour ?? 0) ||
                    _startTime.minute !=
                        (widget.suggestedStartTime?.minute ?? 0) ||
                    _endTime.minute != (widget.suggestedEndTime?.minute ?? 0) ||
                    double.tryParse(_unitsController.text) != null)) ||
            (!_isNew &&
                (TimeOfDay.fromDateTime(_basal!.startTime) !=
                        _startTime ||
                    TimeOfDay.fromDateTime(_basal!.endTime) != _endTime ||
                    (double.tryParse(_unitsController.text) ?? 0) !=
                        _basal!.units)))) {
      Dialogs.showCancelConfirmationDialog(
        context: context,
        isNew: _isNew,
        onSave: handleSaveAction,
      );
    } else {
      Navigator.pop(context);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(
            '${_isNew ? 'New' : 'Edit'} Basal Rate for ${BasalProfile.get(widget.basalProfileId)?.name}'),
      ),
      drawer: const Navigation(currentLocation: BasalDetailScreen.routeName),
      body: Column(
        children: [
          StyledForm(
            formState: _basalForm,
            fields: [
              Row(
                children: [
                  Expanded(
                    child: Padding(
                      padding: const EdgeInsets.only(right: 5),
                      child: StyledTimeOfDayFormField(
                        label: 'Start Time',
                        controller: _startTimeController,
                        time: _startTime,
                        onChanged: (newStartTime) {
                          if (newStartTime != null) {
                            setState(() {
                              _startTime = newStartTime;
                            });
                            updateStartTime();
                          }
                        },
                      ),
                    ),
                  ),
                  Expanded(
                    child: Padding(
                      padding: const EdgeInsets.only(left: 5),
                      child: StyledTimeOfDayFormField(
                        label: 'End Time',
                        controller: _endTimeController,
                        time: _endTime,
                        onChanged: (newEndTime) {
                          if (newEndTime != null) {
                            setState(() {
                              _endTime = newEndTime;
                            });
                            updateEndTime();
                          }
                        },
                      ),
                    ),
                  ),
                ],
              ),
              TextFormField(
                controller: _unitsController,
                keyboardType:
                    const TextInputType.numberWithOptions(decimal: true),
                decoration: const InputDecoration(
                  labelText: 'Units',
                  suffixText: 'U',
                ),
                validator: (value) {
                  if (value!.trim().isEmpty) {
                    return 'Empty amount of units';
                  }
                  return null;
                },
              ),
            ],
          ),
        ],
      ),
      bottomNavigationBar: DetailBottomRow(
        onCancel: handleCancelAction,
        onSave: _isSaving ? null : handleSaveAction,
      ),
    );
  }
}