main.dart

import 'dart:async';
import 'dart:convert';
import 'dart:developer';
import 'dart:io';

import 'package:flutter/cupertino.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_paystack_payment/flutter_paystack_payment.dart';
import 'package:http/http.dart' as http;

// To get started quickly, change this to your heroku deployment of
// https://github.com/PaystackHQ/sample-charge-card-backend
// Step 1. Visit https://github.com/PaystackHQ/sample-charge-card-backend
// Step 2. Click "Deploy to heroku"
// Step 3. Login with your heroku credentials or create a free heroku account
// Step 4. Provide your secret key and an email with which to start all test transactions
// Step 5. Replace {YOUR_BACKEND_URL} below with the url generated by heroku (format https://some-url.herokuapp.com)
String backendUrl = '{YOUR_BACKEND_URL}';
// Set this to a public key that matches the secret key you supplied while creating the heroku instance
String paystackPublicKey = 'pk_live_bba533691a6907c84d78a5c54a2133bdd430f445';
const String appName = 'Paystack Example';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      title: appName,
      home: HomePage(),
    );
  }
}

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

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  final _scaffoldKey = GlobalKey<ScaffoldState>();
  final _formKey = GlobalKey<FormState>();
  final _verticalSizeBox = const SizedBox(height: 20.0);
  final _horizontalSizeBox = const SizedBox(width: 10.0);
  final plugin = PaystackPayment();
  final _border = Container(
    width: double.infinity,
    height: 1.0,
    color: Colors.red,
  );
  int _radioValue = 0;
  CheckoutMethod _method = CheckoutMethod.selectable;
  bool _inProgress = false;
  String? _cardNumber;
  String? _cvv;
  int? _expiryMonth;
  int? _expiryYear;

  @override
  void initState() {
    plugin.initialize(publicKey: paystackPublicKey);
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      key: _scaffoldKey,
      appBar: AppBar(title: const Text(appName)),
      body: Container(
        padding: const EdgeInsets.all(20.0),
        child: Form(
          key: _formKey,
          child: SingleChildScrollView(
            child: ListBody(
              children: <Widget>[
                Row(
                  crossAxisAlignment: CrossAxisAlignment.center,
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  children: <Widget>[
                    const Expanded(
                      child: Text('Initalize transaction from:'),
                    ),
                    Expanded(
                      child: Column(
                          mainAxisSize: MainAxisSize.min,
                          children: <Widget>[
                            RadioListTile<int>(
                              value: 0,
                              groupValue: _radioValue,
                              onChanged: _handleRadioValueChanged,
                              title: const Text('Local'),
                            ),
                            RadioListTile<int>(
                              value: 1,
                              groupValue: _radioValue,
                              onChanged: _handleRadioValueChanged,
                              title: const Text('Server'),
                            ),
                          ]),
                    )
                  ],
                ),
                _border,
                _verticalSizeBox,
                TextFormField(
                  decoration: const InputDecoration(
                    border: UnderlineInputBorder(),
                    labelText: 'Card number',
                  ),
                  onSaved: (String? value) => _cardNumber = value,
                ),
                _verticalSizeBox,
                Row(
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  crossAxisAlignment: CrossAxisAlignment.center,
                  children: <Widget>[
                    Expanded(
                      child: TextFormField(
                        decoration: const InputDecoration(
                          border: UnderlineInputBorder(),
                          labelText: 'CVV',
                        ),
                        onSaved: (String? value) => _cvv = value,
                      ),
                    ),
                    _horizontalSizeBox,
                    Expanded(
                      child: TextFormField(
                        decoration: const InputDecoration(
                          border: UnderlineInputBorder(),
                          labelText: 'Expiry Month',
                        ),
                        onSaved: (String? value) =>
                            _expiryMonth = int.tryParse(value ?? ""),
                      ),
                    ),
                    _horizontalSizeBox,
                    Expanded(
                      child: TextFormField(
                        decoration: const InputDecoration(
                          border: UnderlineInputBorder(),
                          labelText: 'Expiry Year',
                        ),
                        onSaved: (String? value) =>
                            _expiryYear = int.tryParse(value ?? ""),
                      ),
                    )
                  ],
                ),
                _verticalSizeBox,
                Theme(
                  data: Theme.of(context).copyWith(
                    primaryColorLight: Colors.white,
                    primaryColorDark: navyBlue,
                    textTheme: Theme.of(context).textTheme.copyWith(
                          bodyMedium: const TextStyle(
                            color: lightBlue,
                          ),
                        ),
                    colorScheme:
                        ColorScheme.fromSwatch().copyWith(secondary: green),
                  ),
                  child: Builder(
                    builder: (context) {
                      return _inProgress
                          ? Container(
                              alignment: Alignment.center,
                              height: 50.0,
                              child: kIsWeb
                                  ? const CircularProgressIndicator()
                                  : Platform.isIOS
                                      ? const CupertinoActivityIndicator()
                                      : const CircularProgressIndicator(),
                            )
                          : Column(
                              mainAxisSize: MainAxisSize.min,
                              children: <Widget>[
                                _getPlatformButton(
                                    'Charge Card', () => _startAfreshCharge()),
                                _verticalSizeBox,
                                _border,
                                const SizedBox(
                                  height: 40.0,
                                ),
                                Row(
                                  mainAxisAlignment:
                                      MainAxisAlignment.spaceBetween,
                                  crossAxisAlignment: CrossAxisAlignment.center,
                                  children: <Widget>[
                                    Flexible(
                                      flex: 3,
                                      child: DropdownButtonHideUnderline(
                                        child: InputDecorator(
                                          decoration: const InputDecoration(
                                            border: OutlineInputBorder(),
                                            isDense: true,
                                            hintText: 'Checkout method',
                                          ),
                                          child: DropdownButton<CheckoutMethod>(
                                            value: _method,
                                            isDense: true,
                                            onChanged: (CheckoutMethod? value) {
                                              if (value != null) {
                                                setState(() => _method = value);
                                              }
                                            },
                                            items: banks.map((String value) {
                                              return DropdownMenuItem<
                                                  CheckoutMethod>(
                                                value:
                                                    _parseStringToMethod(value),
                                                child: Text(value),
                                              );
                                            }).toList(),
                                          ),
                                        ),
                                      ),
                                    ),
                                    _horizontalSizeBox,
                                    Flexible(
                                      flex: 2,
                                      child: SizedBox(
                                        width: double.infinity,
                                        child: _getPlatformButton(
                                          'Checkout',
                                          () => _handleCheckout(context),
                                        ),
                                      ),
                                    ),
                                  ],
                                )
                              ],
                            );
                    },
                  ),
                )
              ],
            ),
          ),
        ),
      ),
    );
  }

  void _handleRadioValueChanged(int? value) {
    if (value != null) setState(() => _radioValue = value);
  }

  _handleCheckout(BuildContext? context) async {
    if (_method != CheckoutMethod.card && _isLocal) {
      _showMessage('Select server initialization method at the top');
      return;
    }
    setState(() => _inProgress = true);
    _formKey.currentState?.save();
    Charge charge = Charge()
      ..amount = 20 * 100 // In base currency
      ..email = 'customer@email.com'
      ..card = _getCardFromUI();

    if (!_isLocal) {
      var accessCode = await _fetchAccessCodeFrmServer(_getReference());
      charge.accessCode = accessCode;
    } else {
      charge.reference = _getReference();
    }

    try {
      CheckoutResponse response = await plugin.checkout(
        context!,
        method: _method,
        charge: charge,
        fullscreen: false,
        logo: const MyLogo(),
      );
      log('Response = $response');
      setState(() => _inProgress = false);
      _updateStatus(response.reference, '$response');
    } catch (e) {
      setState(() => _inProgress = false);
      _showMessage("Check console for error");
      rethrow;
    }
  }

  _startAfreshCharge() async {
    _formKey.currentState?.save();

    Charge charge = Charge();
    charge.card = _getCardFromUI();

    setState(() => _inProgress = true);

    if (_isLocal) {
      // Set transaction params directly in app (note that these params
      // are only used if an access_code is not set. In debug mode,
      // setting them after setting an access code would throw an exception

      charge
        ..amount = 20 * 100 // In base currency
        ..email = 'customer@email.com'
        ..reference = _getReference()
        ..putCustomField('Charged From', 'Flutter SDK');
      // _getReference();
      log(charge.reference!);
      _chargeCard(charge, scanCard: true);
    } else {
      // Perform transaction/initialize on Paystack server to get an access code
      // documentation: https://developers.paystack.co/reference#initialize-a-transaction
      charge.accessCode = await _fetchAccessCodeFrmServer(_getReference());
      _chargeCard(charge, scanCard: true);
    }
  }

  _chargeCard(Charge charge, {required bool scanCard}) async {
    final response =
        await plugin.chargeCard(context, charge: charge, scanCard: scanCard);
    log(response.reference!);
    final reference = response.reference;

    // Checking if the transaction is successful
    if (response.status) {
      _verifyOnServer(reference);
      return;
    }

    // The transaction failed. Checking if we should verify the transaction
    if (response.verify) {
      _verifyOnServer(reference);
    } else {
      setState(() => _inProgress = false);
      _updateStatus(reference, response.message);
    }
  }

  String _getReference() {
    String platform;
    if (!kIsWeb) {
      if (Platform.isIOS) {
        platform = 'iOS';
      } else if (Platform.isLinux) {
        platform = 'Linux';
      } else if (Platform.isMacOS) {
        platform = 'MacOS';
      } else if (Platform.isFuchsia) {
        platform = 'Fuchsia';
      } else if (Platform.isWindows) {
        platform = 'Windows';
      } else {
        platform = 'Android';
      }
      // platform = 'Unknown';
    } else {
      platform = "WEB";
    }

    return 'ChargedFrom${platform}_${DateTime.now().millisecondsSinceEpoch}';
  }

  PaymentCard _getCardFromUI() {
    // Using just the must-required parameters.
    return PaymentCard(
      number: _cardNumber,
      cvc: _cvv,
      expiryMonth: _expiryMonth,
      expiryYear: _expiryYear,
    );

    // Using Cascade notation (similar to Java's builder pattern)
//    return PaymentCard(
//        number: cardNumber,
//        cvc: cvv,
//        expiryMonth: expiryMonth,
//        expiryYear: expiryYear)
//      ..name = 'Segun Chukwuma Adamu'
//      ..country = 'Nigeria'
//      ..addressLine1 = 'Ikeja, Lagos'
//      ..addressPostalCode = '100001';

    // Using optional parameters
//    return PaymentCard(
//        number: cardNumber,
//        cvc: cvv,
//        expiryMonth: expiryMonth,
//        expiryYear: expiryYear,
//        name: 'Ismail Adebola Emeka',
//        addressCountry: 'Nigeria',
//        addressLine1: '90, Nnebisi Road, Asaba, Deleta State');
  }

  Widget _getPlatformButton(String string, Function() function) {
    // is still in progress
    Widget widget;
    if (!kIsWeb) {
      if (Platform.isIOS) {
        widget = CupertinoButton(
          onPressed: function,
          padding: const EdgeInsets.symmetric(horizontal: 15.0),
          color: CupertinoColors.activeBlue,
          child: Text(
            string,
            maxLines: 1,
            overflow: TextOverflow.ellipsis,
          ),
        );
        return widget;
      } else {
        widget = ElevatedButton(
          onPressed: function,
          child: Text(
            string.toUpperCase(),
            style: const TextStyle(fontSize: 17.0),
          ),
        );
        return widget;
      }
    } else {
      widget = ElevatedButton(
        onPressed: function,
        child: Text(
          string.toUpperCase(),
          style: const TextStyle(fontSize: 17.0),
        ),
      );
      return widget;
    }
  }

  Future<String?> _fetchAccessCodeFrmServer(String reference) async {
    String url = 'https://sdgfortb.herokuapp.com/paystack/new-access-code';
    String? accessCode;
    try {
      log("Access code url = $url");
      http.Response response = await http.post(Uri.parse(url),
          headers: {"Content-Type": "application/json"},
          body: json.encode({
            "email": "oreofesolarin@gmail.com",
            "amount": 1000000,
            // "reference": reference
          }));
      accessCode = response.body;
      log('Response for access code = $accessCode');
    } catch (e) {
      setState(() => _inProgress = false);
      _updateStatus(
          reference,
          'There was a problem getting a new access code form'
          ' the backend: $e');
    }

    return accessCode;
  }

  void _verifyOnServer(String? reference) async {
    var head = {
      "Authorization":
          "Bearer sk_live_23f9d7b1689c5f7630e364b80359ae5cf730b2b1", // TODO Remove sensitive data
    };
    _updateStatus(reference, 'Verifying...');
    String url = 'https://api.paystack.co/transaction/verify/$reference';
    try {
      http.Response response = await http.get(Uri.parse(url), headers: head);
      var body = response.body;
      _updateStatus(reference, body);
    } catch (e) {
      _updateStatus(
          reference,
          'There was a problem verifying %s on the backend: '
          '$reference $e');
    }
    setState(() => _inProgress = false);
  }

  _updateStatus(String? reference, String message) {
    _showMessage('Reference: $reference \n Response: $message',
        const Duration(seconds: 7));
  }

  _showMessage(String message,
      [Duration duration = const Duration(seconds: 4)]) {
    ScaffoldMessenger.of(context).showSnackBar(SnackBar(
      content: Text(message),
      duration: duration,
      action: SnackBarAction(
          label: 'CLOSE',
          onPressed: () =>
              ScaffoldMessenger.of(context).removeCurrentSnackBar()),
    ));
  }

  bool get _isLocal => _radioValue == 0;
}

var banks = ['Selectable', 'Bank', 'Card'];

CheckoutMethod _parseStringToMethod(String string) {
  CheckoutMethod method = CheckoutMethod.selectable;
  switch (string) {
    case 'Bank':
      method = CheckoutMethod.bank;
      break;
    case 'Card':
      method = CheckoutMethod.card;
      break;
  }
  return method;
}

class MyLogo extends StatelessWidget {
  const MyLogo({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(
      decoration: const BoxDecoration(
        shape: BoxShape.circle,
        color: Colors.black,
      ),
      alignment: Alignment.center,
      padding: const EdgeInsets.all(10),
      child: const Text(
        "CO",
        style: TextStyle(
          color: Colors.white,
          fontSize: 13,
          fontWeight: FontWeight.bold,
        ),
      ),
    );
  }
}

const Color green = Color(0xFF3db76d);
const Color lightBlue = Color(0xFF34a5db);
const Color navyBlue = Color(0xFF031b33);