comunicmobile/lib/ui/widgets/survey_widget.dart

import 'package:comunic/helpers/survey_helper.dart';
import 'package:comunic/models/survey.dart';
import 'package:comunic/models/survey_choice.dart';
import 'package:comunic/utils/intl_utils.dart';
import 'package:comunic/utils/ui_utils.dart';
import 'package:flutter/material.dart';
import 'package:pie_chart/pie_chart.dart';

/// Survey widget
///
/// @author Pierre HUBERT

class SurveyWidget extends StatefulWidget {
  final Survey survey;

  const SurveyWidget({Key key, @required this.survey})
      : assert(survey != null),
        super(key: key);

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

class _SurveyWidgetState extends State<SurveyWidget> {
  final SurveyHelper _helper = SurveyHelper();

  Survey get survey => widget.survey;

  Map<String, double> _buildDataMap() {
    Map<String, double> data = Map();
    widget.survey.choices.forEach((e) => data.putIfAbsent(
        e.name + " (" + e.responses.toString() + ")", () => 1.0 * e.responses));
    return data;
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: <Widget>[
        Text(
          widget.survey.question,
          style: TextStyle(fontWeight: FontWeight.bold),
        ),
        _buildUserResponse(),
        survey.hasResponses ? _buildChart() : _buildNoResponseNotice(),
      ],
    );
  }

  Widget _buildUserResponse() {
    if (survey.hasResponded) return _buildUserRespondedWidget();
    return _buildUserResponseFormWidget();
  }

  Widget _buildUserRespondedWidget() {
    return Row(
      mainAxisAlignment: MainAxisAlignment.center,
      children: <Widget>[
        Flexible(
          child: Text(
            tr("Your response: %response%",
                args: {"response": survey.userResponse.name}),
            textAlign: TextAlign.center,
          ),
        ),
        MaterialButton(
          child: Text(tr("Cancel").toUpperCase()),
          onPressed: _cancelUserResponse,
        )
      ],
    );
  }

  Future<void> _cancelUserResponse() async {
    if (!await showConfirmDialog(
      context: context,
      title: tr("Cancel response to survey"),
      message:
          tr("Do you really want to cancel your response to this survey ?"),
    )) return;

    if (!await _helper.cancelResponse(survey)) {
      showSimpleSnack(
          context, tr("Could not cancel your response to the survey !"));
      return;
    }

    setState(() {
      survey.cancelUserResponse();
    });
  }

  Widget _buildUserResponseFormWidget() {
    return ConstrainedBox(
      constraints: BoxConstraints(maxWidth: 300),
      child: DropdownButton<SurveyChoice>(
        isExpanded: true,
        hint: Text(tr("Respond to survey")),
        items: survey.choices
            .map(
              (f) => DropdownMenuItem<SurveyChoice>(
                value: f,
                child: Text(f.name),
              ),
            )
            .toList(),
        onChanged: _respondToSurvey,
      ),
    );
  }

  Widget _buildChart() {
    return PieChart(
      dataMap: _buildDataMap(),
    );
  }

  Widget _buildNoResponseNotice() {
    return Padding(
      padding: const EdgeInsets.all(16.0),
      child: Text(tr("No response yet to this survey.")),
    );
  }

  /// Respond to survey
  Future<void> _respondToSurvey(SurveyChoice choice) async {
    // Send the response to the server
    if (!await _helper.respondToSurvey(survey: survey, choice: choice))
      return showSimpleSnack(
          context, tr("Could not send your response to the survey!"));

    setState(() {
      survey.setUserResponse(choice);
    });
  }
}