mobile_nebula/lib/screens/EnrollmentScreen.dart

import 'dart:async';
import 'dart:io';

import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_platform_widgets/flutter_platform_widgets.dart';

import 'package:mobile_nebula/components/SimplePage.dart';
import 'package:mobile_nebula/components/buttons/PrimaryButton.dart';
import 'package:url_launcher/url_launcher.dart';

import '../components/config/ConfigItem.dart';
import '../components/config/ConfigSection.dart';

class EnrollmentScreen extends StatefulWidget {
  final String? code;
  final StreamController? stream;
  final bool allowCodeEntry;

  static const routeName = '/v1/mobile-enrollment';

  // Attempts to find an enrollment code in the provided url. If one is not found then assume the input was
  // an enrollment code. Primarily to support manual dn enrollment where the user can input a code or a url.
  static String parseCode(String url) {
    final uri = Uri.parse(url);
    if (uri.path != EnrollmentScreen.routeName) {
      return url;
    }

    if (uri.hasFragment) {
      final qp = Uri.splitQueryString(uri.fragment);
      return qp["code"] ?? "";
    }

    return url;
  }

  const EnrollmentScreen({super.key, this.code, this.stream, this.allowCodeEntry = false});

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

class _EnrollmentScreenState extends State<EnrollmentScreen> {
  String? error;
  var enrolled = false;
  var enrollInput = TextEditingController();
  String? code;

  static const platform = MethodChannel('net.defined.mobileNebula/NebulaVpnService');

  void initState() {
    code = widget.code;
    super.initState();
    _enroll();
  }

  @override
  void dispose() {
    enrollInput.dispose();
    super.dispose();
  }

  _enroll() async {
    try {
      await platform.invokeMethod("dn.enroll", code);
      setState(() {
        enrolled = true;
        if (widget.stream != null) {
          // Signal a new site has been added
          widget.stream!.add(null);
        }
      });
    } on PlatformException catch (err) {
      setState(() {
        error = err.details ?? err.message;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    final colorScheme = Theme.of(context).colorScheme;
    final textTheme = Theme.of(context).textTheme;
    final bodyTextStyle = textTheme.bodyLarge!.apply(color: colorScheme.onPrimary);
    final contactUri = Uri.parse('mailto:support@defined.net');

    Widget child;
    AlignmentGeometry? alignment;

    if (code == null) {
      if (widget.allowCodeEntry) {
        child = _codeEntry();
      } else {
        // No code, show the error
        child = Padding(
            child: Center(
                child: Text(
              'No valid enrollment code was found.\n\nContact your administrator to obtain a new enrollment code.',
              textAlign: TextAlign.center,
            )),
            padding: EdgeInsets.only(top: 20));
      }
    } else if (this.error != null) {
      // Error while enrolling, display it
      child = Center(
          child: Column(
        children: [
          Padding(
              child: SelectableText(
                  'There was an issue while attempting to enroll this device. Contact your administrator to obtain a new enrollment code.'),
              padding: EdgeInsets.symmetric(horizontal: 16, vertical: 20)),
          Padding(
              child: SelectableText.rich(TextSpan(children: [
                TextSpan(text: 'If the problem persists, please let us know at '),
                TextSpan(
                  text: 'support@defined.net',
                  style: bodyTextStyle.apply(color: colorScheme.primary),
                  recognizer: TapGestureRecognizer()
                    ..onTap = () async {
                      if (await canLaunchUrl(contactUri)) {
                        print(await launchUrl(contactUri));
                      }
                    },
                ),
                TextSpan(text: ' and provide the following error:'),
              ])),
              padding: EdgeInsets.symmetric(horizontal: 16, vertical: 10)),
          Container(
            child: Padding(child: SelectableText(this.error!), padding: EdgeInsets.all(16)),
            color: Theme.of(context).colorScheme.errorContainer,
          ),
        ],
        crossAxisAlignment: CrossAxisAlignment.center,
        mainAxisAlignment: MainAxisAlignment.center,
      ));
    } else if (this.enrolled) {
      // Enrollment complete!
      child = Padding(
          child: Center(
              child: Text(
            'Enrollment complete! 🎉',
            textAlign: TextAlign.center,
          )),
          padding: EdgeInsets.only(top: 20));
    } else {
      // Have a code and actively enrolling
      alignment = Alignment.center;
      child = Center(
          child: Column(children: [
        Padding(child: Text('Contacting DN for enrollment'), padding: EdgeInsets.only(bottom: 25)),
        PlatformCircularProgressIndicator(cupertino: (_, __) {
          return CupertinoProgressIndicatorData(radius: 50);
        })
      ]));
    }

    return SimplePage(title: Text('Enroll with Managed Nebula'), child: child, alignment: alignment);
  }

  Widget _codeEntry() {
    final GlobalKey<FormState> _formKey = GlobalKey<FormState>();

    String? validator(String? value) {
      if (value == null || value.isEmpty) {
        return 'Code or link is required';
      }
      return null;
    }

    Future<void> onSubmit() async {
      final bool isValid = _formKey.currentState?.validate() ?? false;
      if (!isValid) {
        return;
      }

      setState(() {
        code = EnrollmentScreen.parseCode(enrollInput.text);
        error = null;
        _enroll();
      });
    }

    final input = Padding(
        padding: EdgeInsets.symmetric(horizontal: 16),
        child: PlatformTextFormField(
          controller: enrollInput,
          validator: validator,
          hintText: 'from admin.defined.net',
          cupertino: (_, __) => CupertinoTextFormFieldData(
            prefix: Text("Code or link"),
          ),
          material: (_, __) => MaterialTextFormFieldData(
            decoration: const InputDecoration(labelText: 'Code or link'),
          ),
        ));

    final form = Form(
      key: _formKey,
      child: Platform.isAndroid ? input : ConfigSection(children: [input]),
    );

    return Column(children: [
      Padding(
        padding: EdgeInsets.symmetric(vertical: 32),
        child: form,
      ),
      Padding(
          padding: EdgeInsets.symmetric(horizontal: 16),
          child: Row(children: [Expanded(child: PrimaryButton(child: Text('Submit'), onPressed: onSubmit))]))
    ]);
  }
}