BotZ_app/lib/ui/server_form.dart

import 'package:flutter/material.dart';
import 'package:logger/logger.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'dart:convert';

import 'dialog.dart';
import '../utils/verify_server.dart';

final log = Logger();

class ServerForm extends StatefulWidget {
  ServerForm({@required this.defaultNextRoute, Key key}) : super(key: key);
  final String title = "Server data";
  final String defaultNextRoute;

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

class _ServerFormState extends State<ServerForm> {
  static String title = "Server info";
  Uri zAddress;
  Uri botZAddress;
  bool _autoValidate = false;
  bool _disableFields = false;
  final _serverFormKey = GlobalKey<FormState>();
  final _scaffoldKey = GlobalKey<ScaffoldState>();

  final zController = TextEditingController();
  final botZController = TextEditingController();

  InputDecoration _textFieldDecoration(String label, IconData icon) {
    return InputDecoration(
      labelText: label,
      icon: Icon(icon),
      hintText: 'Please, insert $label address',
    );
  }

  SnackBar showProgress() {
    return SnackBar(
        content: Row(
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      children: <Widget>[
        CircularProgressIndicator(
          value: null,
          strokeWidth: 7.0,
        ),
        Text('Processing Data')
      ],
    ));
  }

  String validateServer(String address) {
    if (address.isEmpty) {
      return 'Server address must not be empty';
    }
    try {
      Uri.parse(address);
    } on FormatException catch (e) {
      return e.toString();
    }
    return null;
  }

  String validateZServer(String address) {
    String baseValidation = this.validateServer(address);
    if (baseValidation != null) {
      return baseValidation;
    }
    if (utf8.encode(address).length > 72) {
      return "Server address string length is > 72 bytes. Refusing to go on.";
    }
    return null;
  }

  Future<String> getNextRoute() async {
    var persistence = await SharedPreferences.getInstance();
    String nextRoute = persistence.getString("nextRoute");
    if (nextRoute != null) {
      log.d("nextRoute: $nextRoute");
      return nextRoute;
    }
    log.d("defaultNextRoute: ${widget.defaultNextRoute}");
    return null;
  }

  Future<void> _onPressed() async {
    log.d("Button pressed");
    var persistence = await SharedPreferences.getInstance();
    setState(() {
      _disableFields = true;
    });
    _scaffoldKey.currentState.showSnackBar(this.showProgress());
    if (!_serverFormKey.currentState.validate()) {
      setState(() {
        _autoValidate = true;
        _disableFields = false;
      });
      _scaffoldKey.currentState.hideCurrentSnackBar();
      return;
    }

    bool resp;
    Uri _botZAddr = Uri.parse(botZController.text);
    Uri _zAddr = Uri.parse(zController.text);
    log.d("Received botZAddr: $_botZAddr\tzAddr: $_zAddr");
    try {
      resp = await verifyServer(_botZAddr, _zAddr);
      log.i("Secret is${resp ? ' ' : ' NOT '}a match");
    } catch (err) {
      log.e("Error: ${err.toString()}");
      showDialog(
          context: context,
          builder: errorDialogBuilder("Error", "${err.toString()}"));
    } finally {
      log.d("Clean the state");
      setState(() {
        _disableFields = false;
      });
      _scaffoldKey.currentState.hideCurrentSnackBar();
    }

    if (!resp) {
      showDialog(
          context: context,
          builder: errorDialogBuilder("Error",
              "The BotZ server does not target the provided Z server."));
    } else {
      _serverFormKey.currentState.save();
      persistence.setString("zAddress", this.zAddress.toString());
      persistence.setString("botZAddress", this.botZAddress.toString());
      String nextRoute = await getNextRoute();
      if (nextRoute == null) {
        nextRoute = widget.defaultNextRoute;
      }
      Navigator.pushNamed(context, nextRoute);
    }

    log.d("Done");
  }

  Form theForm() => Form(
        key: _serverFormKey,
        child: Column(children: <Widget>[
          TextFormField(
              autofocus: true,
              autocorrect: false,
              controller: zController,
              enabled: !_disableFields,
              decoration: this._textFieldDecoration("Z server", Icons.http),
              validator: this.validateZServer,
              autovalidate: _autoValidate,
              onSaved: (String addr) {
                zAddress = Uri.parse(addr);
              }),
          TextFormField(
              autocorrect: false,
              controller: botZController,
              enabled: !_disableFields,
              decoration: this._textFieldDecoration("BotZ server", Icons.http),
              validator: this.validateServer,
              autovalidate: _autoValidate,
              onSaved: (String addr) {
                botZAddress = Uri.parse(addr);
              }),
          RaisedButton(
            onPressed: _onPressed,
            child: Text('Save'),
          ),
        ]),
      );

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        key: _scaffoldKey, appBar: AppBar(title: Text(title)), body: theForm());
  }
}