import 'dart:convert';
import 'dart:io';
import 'package:flutter/material.dart';
import 'datamodel.dart';
import 'package:http/http.dart' as http;
import 'sensorconnector.dart';

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

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

class _ViewEvents extends State<ViewEvents> {
  // Get singleton to access locally stored events:
  EventStoreInstance _events = EventStoreInstance();
  String _sync_status = '';
  //TODO: add exception handling and display exceptions to user.

  @override
  void initState() {
    _sync_status = _events.getPendingEventCount().toString() + ' event(s) pending';
    super.initState();

    //TODO: Query all events from database everytime this widget is opened. Remove local event storage instance!
  }

  Future<void> syncEvents() async {
    final ConfigurationStoreInstance configuration = ConfigurationStoreInstance();
    SensorConnector connection = SensorConnector();
    int syncCounter = _events.getPendingEventCount();; //For displaying progress during event upload

    if(syncCounter > 0) {
      try {
        String? token = await connection.getAuthToken(
            configuration.loginInformation.mail,
            configuration.loginInformation.password);

        if (token != null) {
          debugPrint('Number of Events: ' + _events.events.length.toString());
          debugPrint('Number of Pending Events: ' + syncCounter.toString());
          var index = 0;
          for (var event in _events.events) {
            if (event.status == 'PENDING') {  //TODO: only query events which are 'PENDING' from database.
              debugPrint('Idx: ' + index.toString() + ' ' +
                  event.toSensorJson().toString());
              index++;
              if (await connection.putEvent(event, token) == true) {
                //Event has been posted to Sensor.
                syncCounter--;
                debugPrint(
                    'put success, remaining events: ' + syncCounter.toString());
                event.status = 'EXPORTED'; //Update event export only once    //TODO: move to database and update event based in primary row id.
                setState(() {});
              } else {
                throw Exception('Sync for ' + event.urn + 'failed');
              }
            }
          }
          _sync_status = 'export success';
        }
      } on SocketException catch (e) {
        debugPrint('Exception: $e');
        _sync_status = 'No connection';
        setState(() {});
      } catch (e) {
        debugPrint('Exception: $e');
        _sync_status = '$e';
        setState(() {});
      }
    }else{
      debugPrint('Nothing to export');
    }
  }

  @override
  Widget build(BuildContext context) {

    return Scaffold(
      appBar: AppBar(
        title: const Text("View & Sync"),
      ),
      body: Container(
        margin: const EdgeInsets.symmetric(horizontal: 5.0),
        child:
        SingleChildScrollView(
          scrollDirection: Axis.horizontal,
          child: SingleChildScrollView(
            scrollDirection: Axis.vertical,
            child: DataTable(

              columns: const <DataColumn>[
                DataColumn(
                  label: Text(
                    'Id',
                    style: TextStyle(fontStyle: FontStyle.italic),
                  ),
                ),
                DataColumn(
                  label: Text(
                    'URN',
                    style: TextStyle(fontStyle: FontStyle.italic),
                  ),
                ),
                DataColumn(
                  label: Text(
                    'Label',
                    style: TextStyle(fontStyle: FontStyle.italic),
                  ),
                ),
                DataColumn(
                  label: Text(
                    'Type',
                    style: TextStyle(fontStyle: FontStyle.italic),
                  ),
                ),
                DataColumn(
                  label: Text(
                    'Description',
                    style: TextStyle(fontStyle: FontStyle.italic),
                  ),
                ),
                DataColumn(
                  label: Text(
                    'StartDate',
                    style: TextStyle(fontStyle: FontStyle.italic),
                  ),
                ),
                DataColumn(
                  label: Text(
                    'EndDate',
                    style: TextStyle(fontStyle: FontStyle.italic),
                  ),
                ),
                DataColumn(
                  label: Text(
                    'Latitude',
                    style: TextStyle(fontStyle: FontStyle.italic),
                  ),
                ),
                DataColumn(
                  label: Text(
                    'Longitude',
                    style: TextStyle(fontStyle: FontStyle.italic),
                  ),
                ),
                DataColumn(
                  label: Text(
                    'Elevation',
                    style: TextStyle(fontStyle: FontStyle.italic),
                  ),
                ),
                DataColumn(
                  label: Text(
                    'Status',
                    style: TextStyle(fontStyle: FontStyle.italic),
                  ),
                ),
              ],
              rows: <DataRow>[
                for (var event in _events.events)
                  DataRow(
                    cells: <DataCell>[
                      DataCell(Text(event.id.toString())),
                      DataCell(Text(event.urn)),
                      DataCell(
                        TextFormField(
                          readOnly: true,
                          initialValue: event.label,
                          onFieldSubmitted: (val) {
                            event.label = val; //Update Database
                          },
                        ),
                      ),
                      DataCell(Text(event.type)),
                      DataCell(
                        TextFormField(
                          readOnly: true,
                          initialValue: event.description,
                          onFieldSubmitted: (val) {
                            event.description = val; //Update Database
                          },
                        ),
                      ),
                      DataCell(Text(event.startDate)),
                      DataCell(Text(event.endDate)),
                      DataCell(
                        TextFormField(
                          readOnly: true,
                          initialValue: event.latitude,
                          onFieldSubmitted: (val) {
                            event.latitude = val; //Update Database
                          },
                        ),
                      ),
                      DataCell(
                        TextFormField(
                          readOnly: true,
                          initialValue: event.longitude,
                          onFieldSubmitted: (val) {
                            event.longitude = val; //Update Database
                          },
                        ),
                      ),
                      DataCell(
                        TextFormField(
                          readOnly: true,
                          initialValue: event.elevation,
                          onFieldSubmitted: (val) {
                            event.elevation = val; //Update Database
                          },
                        ),
                      ),
                      DataCell(
                        TextFormField(
                          readOnly: true,
                          controller: TextEditingController(  //Required to update field here
                            text: event.status,
                          ),
                          onFieldSubmitted: (val) {
                            event.status = val; //Update Database
                          },
                        ),
                      ),
                    ],
                  ),
              ],
            ),
          ),
        ),
      ),
      bottomNavigationBar: Row(
        mainAxisAlignment: MainAxisAlignment.end,
        children: [
          const SizedBox(width: 10),
          Text(_sync_status),
          const SizedBox(width: 50),
          Container(
            margin: const EdgeInsets.symmetric(vertical: 10.0),
            child:
            FloatingActionButton.extended(
              heroTag: null,
              tooltip: 'Upload Events',
              icon: null,
              label: const Text('Sync'),
              onPressed: () {
                debugPrint(_events.getEventDump());


                syncEvents();
              },
            ),
          ),
          const SizedBox(width: 5.0),
        ],
      ),
    );
  }
}
//TODO: allow editing fields here. Check validation of input value!