addevent.dart

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_datetime_picker/flutter_datetime_picker.dart';
import 'datamodel.dart';
import 'dart:async';
import 'package:geolocator/geolocator.dart';

class AddEvent extends StatefulWidget {
  const AddEvent({Key? key}) : super(key: key);

  @override
  State<AddEvent> createState() => _AddEventPageState();
}

class _AddEventPageState extends State<AddEvent>  {
  bool syncGNSSData = true;
  late String long = "";
  late String lat = "";
  late String alt = "";
  late double accuracy = 0.0;
  late StreamSubscription<Position> streamHandler;

  Future startGNSS() async {
    debugPrint("Check Location Permission");
    bool serviceStatus = false;
    bool hasPermission = false;
    serviceStatus = await Geolocator.isLocationServiceEnabled();
    if(serviceStatus){
      LocationPermission permission = await Geolocator.checkPermission();

      if (permission == LocationPermission.denied) {
        permission = await Geolocator.requestPermission();
        if (permission == LocationPermission.denied) {
          debugPrint('Location permissions are denied');
        }else if(permission == LocationPermission.deniedForever){
          debugPrint('Location permissions are permanently denied');
        }else{
          hasPermission = true;
        }
      }else{
        hasPermission = true;
      }
      if(hasPermission){
        debugPrint('Location permissions granted');
        if(mounted){
          setState(() {
            //refresh the UI
          });}
        debugPrint('Starting location stream');
        streamHandler = Geolocator.getPositionStream(
            locationSettings: const LocationSettings(
              accuracy: LocationAccuracy.high,
              distanceFilter: 0,
            )).listen((Position position) {
          debugPrint('Get Location: Lat:' + position.latitude.toString() +
              ' Long:' + position.longitude.toString() +
              ' Alt:' + position.altitude.toString());

          long = position.longitude.toString();
          lat = position.latitude.toString();
          alt = position.altitude.toString();
          accuracy = position.accuracy;

          if (syncGNSSData == true) {
            if(mounted){
              setState(() {
                //refresh UI on update
              });}
          }
        });
      }
    }else{
      debugPrint("GPS Service is not enabled, turn on GPS location");
    }
    if(mounted){
      setState(() {
        //refresh the UI
      });}
  }

  @override
  void initState() {
    startGNSS();

    super.initState();
  }

  @override
  void dispose() {

    try {
      streamHandler.cancel();
      debugPrint('Cancel location stream');
    }catch(e){
      debugPrint('Canceling location stream failed');
    }

    super.dispose();
    //TODO: only if initialized positionStream.cancel();
  }

  void _storeCurrentEvent() {
    final EventStoreInstance eventsStore = EventStoreInstance();
    eventsStore.currentEvent.status = "PENDING";
    eventsStore.events.add(
        Event(
            eventsStore.currentEvent.id,
            eventsStore.currentEvent.urn,
            eventsStore.currentEvent.label,
            eventsStore.currentEvent.type,
            eventsStore.currentEvent.description,
            eventsStore.currentEvent.status,
            eventsStore.currentEvent.startDate,
            eventsStore.currentEvent.endDate,
            eventsStore.currentEvent.latitude,
            eventsStore.currentEvent.longitude,
            eventsStore.currentEvent.elevation
        ));
  }

  //TODO: add field validators for freetext fields. Check allowed characters in sensor.awi.de

  @override
  Widget build(BuildContext context) {
    /* Get singletons to access relevant data here.*/
    final EventStoreInstance eventsStore = EventStoreInstance();
    final ConfigurationStoreInstance configuration = ConfigurationStoreInstance();
    String gnssStatusText = "";


    if (true == syncGNSSData){
      // Update current event coordinates from GNSS stream
      eventsStore.currentEvent.latitude = lat;
      eventsStore.currentEvent.longitude = long;
      eventsStore.currentEvent.elevation = alt;

      var date = DateTime.now().toUtc();
      eventsStore.currentEvent.startDate = '$date';
      eventsStore.currentEvent.endDate = '$date';

      if(accuracy == 0.0){
        gnssStatusText = "No-Fix";
      }
      else{
        gnssStatusText = "Precision: "+ accuracy.toStringAsFixed(2) +"m";
      }
    }
    else{
      gnssStatusText = "GNSS Disabled"; // Just display existing event coordinates
    }

    if (configuration.initialized == true) {
      return Scaffold(
        appBar: AppBar(title: const Text("Add Event")),
        body:
        Column(
            mainAxisAlignment: MainAxisAlignment.spaceEvenly,
            children: <Widget>[
              TextFormField(
                initialValue: eventsStore.currentEvent.label,
                autovalidateMode: AutovalidateMode.onUserInteraction,
                decoration: const InputDecoration(
                    labelText: 'Label',
                    errorText: 'Only: a-z , A-Z , _ , 0-9 , ,(Comma) , ( , ) , + , - , . , :'
                ),
                onChanged: (value) {
                  eventsStore.currentEvent.label = value;
                },
                validator: (value) {
                  if (!RegExp(r'^[a-z A-Z . \- 0-9 , ( ) + - _ :]+$').hasMatch(
                      value!)) {
                    return "Only: a-z , A-Z , _ , 0-9 , ,(Comma) , ( , ) , + , - , . , :";
                  } else {
                    eventsStore.currentEvent.label = value;
                    return ''; // Entered Text is valid
                  }
                },
              ),
              DropdownButtonFormField(
                  value: eventsStore.currentEvent.type,
                  isExpanded: true,
                  decoration: const InputDecoration(
                    labelText: 'Event Type',
                  ),
                  items:
                  configuration.eventTypes.map((EventType event) {
                    return DropdownMenuItem(
                      value: event.name,
                      child: Text(event.name),
                    );
                  }).toList(),
                  onChanged: (value) {
                    eventsStore.currentEvent.type = value.toString();
                  }
              ),
              DropdownButtonFormField(
                  value: eventsStore.currentEvent.urn,
                  isExpanded: true,
                  decoration: const InputDecoration(
                    labelText: 'URN',
                  ),
                  items:
                  configuration.devices.map((Device device) {
                    return DropdownMenuItem(
                      value: device.urn,
                      child: Text(device.urn),
                    );
                  }).toList(),
                  onChanged: (value) {
                    eventsStore.currentEvent.urn = value.toString();
                    eventsStore.currentEvent.id =
                        configuration.getDeviceIdFromUrn(value.toString());
                  }
              ),
              TextFormField(
                initialValue: eventsStore.currentEvent.description,
                decoration: const InputDecoration(
                    labelText: 'Description'
                ),
                onChanged: (value) {
                  eventsStore.currentEvent.description = value;
                },
              ),

              Row(
                  mainAxisSize: MainAxisSize.min,
                  children: <Widget>[
                    Flexible(child:
                    TextFormField(
                      controller: TextEditingController(
                          text: eventsStore.currentEvent.startDate),
                      readOnly: true,
                      decoration: const InputDecoration(
                        labelText: 'Timestamp',
                        //helperText: '', //Adds some space below field
                        border: OutlineInputBorder(),
                      ),
                      onTap: () {
                        DatePicker.showDateTimePicker(context,
                            showTitleActions: true,
                            onConfirm: (date) {
                              //Only one field for start and end date.
                              eventsStore.currentEvent.startDate = '$date';
                              eventsStore.currentEvent.endDate = '$date';
                              debugPrint('Date set to : $date');
                              setState(() {});
                            },
                            currentTime: DateTime.now().toUtc(),
                            locale: LocaleType.en);
                      },
                    ),
                    ),
                    ElevatedButton(
                      onPressed: () {
                        var date = DateTime.now().toUtc();
                        eventsStore.currentEvent.startDate = '$date';
                        eventsStore.currentEvent.endDate = '$date';
                        debugPrint('Date set to : ' +
                            eventsStore.currentEvent.endDate.toString());
                        setState(() {});
                      },
                      child: Text('Now'),
                    ),
                  ]
              ),
              TextFormField(
                  readOnly: false,
                  enabled: !syncGNSSData,
                  controller: TextEditingController(
                      text: eventsStore.currentEvent.latitude.toString()),
                  decoration: const InputDecoration(
                    labelText: 'Latitude',
                    border: OutlineInputBorder(),
                  ),
                  onChanged: (value) {
                    eventsStore.currentEvent.latitude = value;
                  }
              ),
              TextFormField(
                  readOnly: false,
                  enabled: !syncGNSSData,
                  controller: TextEditingController(
                      text: eventsStore.currentEvent.longitude.toString()),
                  decoration: const InputDecoration(
                    labelText: 'Longitude',
                    border: OutlineInputBorder(),

                  ),
                  onChanged: (value) {
                    eventsStore.currentEvent.longitude = value;
                  }
              ),
              TextFormField(
                  readOnly: false,
                  enabled: !syncGNSSData,
                  controller: TextEditingController(
                      text: eventsStore.currentEvent.elevation.toString()),
                  decoration: const InputDecoration(
                    labelText: 'Elevation',
                    border: OutlineInputBorder(),
                  ),
                  onChanged: (value) {
                    eventsStore.currentEvent.elevation = value;
                  }
              ),
            ]),
        bottomNavigationBar: Row(
          mainAxisAlignment: MainAxisAlignment.end,
          children: [
            Text(gnssStatusText),
            const SizedBox(width: 10),
            Switch(
              value: syncGNSSData,
              onChanged: (value) {
                syncGNSSData = value;
                debugPrint('Switched to:' + syncGNSSData.toString());

                setState(() {
                  //refresh the UI
                });
              },
            ),
            const SizedBox(width: 50),
            FloatingActionButton(
              heroTag: null,
              onPressed: () {
                _storeCurrentEvent();
                HapticFeedback.vibrate();
              },
              tooltip: 'Add Event',
              child: const Icon(Icons.check),
            ),
            const SizedBox(width: 20),
          ],
        ),
      );
    }else {
      return Scaffold(
        appBar: AppBar(title: const Text("Add Event")),
        body: Column(
          mainAxisAlignment: MainAxisAlignment.spaceEvenly,
          crossAxisAlignment: CrossAxisAlignment.end,
          children: const <Widget>[
            Text(
                '  Visit Configuration first.',
                style: TextStyle(fontSize: 20)
            ),
          ],
        ),
      );
    }
  }
}