firewallet-mobile/lib/send.dart

import 'dart:math';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';
import 'package:flutter_bitcoin/flutter_bitcoin.dart';
import 'package:bip39/bip39.dart' as bip39;
import 'package:bip32/bip32.dart' as bip32;
import 'package:crypto/crypto.dart';
import 'dart:typed_data';
import 'package:firewallet/hns.dart' as hns;

class SendPage extends StatefulWidget {
  SendPage({Key? key, required this.uuid, required this.wallet})
      : super(key: key);

  final String uuid;
  String wallet;

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

class _SendPageState extends State<SendPage> {
  late double walletBalance = 0;
  bool balanceLoaded = false;
  final TextEditingController addressController = TextEditingController();
  final TextEditingController amountController = TextEditingController();

  @override
  void initState() {
    super.initState();
  }

  @override
  void dispose() {
    // Dispose of the controllers when the widget is disposed
    addressController.dispose();
    amountController.dispose();
    super.dispose();
  }

  Future<void> fetchWalletBalance() async {
    if (widget.wallet.isEmpty) {
      walletBalance = 0;
      return;
    }

    if (balanceLoaded) {
      return;
    }

    final response = await http.get(Uri.parse(
        'https://api.firewallet.au/wallet/balance?uuid=${widget.uuid}&name=${widget.wallet}'));
    if (response.statusCode == 200) {
      final data = jsonDecode(response.body);
      print(data);

      setState(() {
        walletBalance = data['available'];
      });
    } else {
      // Handle error
      print('Failed to load wallet balance');
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('${widget.wallet} - Send HNS'),
      ),
      // Get wallet list from api and display here
      body: Center(
        child: LayoutBuilder(
          builder: (BuildContext context, BoxConstraints constraints) {
            return ListView(
              padding: const EdgeInsets.all(16),
              children: <Widget>[
                // Display the wallet balance
                Row(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    Text(
                        'Max ${(walletBalance - 0.02).toStringAsFixed(2)} HNS'),
                    TextButton(
                        onPressed: fetchWalletBalance,
                        child: const Icon(Icons.refresh)),
                  ],
                ),
                // Address input field
                TextField(
                  decoration: const InputDecoration(
                    border: OutlineInputBorder(),
                    labelText: 'Address',
                  ),
                  keyboardType: TextInputType.text,
                  inputFormatters: [
                    FilteringTextInputFormatter.allow(RegExp(r'[a-zA-Z0-9]')),
                  ],
                  controller: addressController,
                ),
                SizedBox(height: 16),
                // Amount input field
                TextField(
                  decoration: const InputDecoration(
                    border: OutlineInputBorder(),
                    labelText: 'Amount',
                    suffix: Text('HNS'),
                  ),
                  keyboardType: TextInputType.number,
                  inputFormatters: [
                    FilteringTextInputFormatter.allow(RegExp(r'[0-9.]')),
                  ],
                  controller: amountController,
                ),
                TextButton(
                    onPressed: () => amountController.text =
                        (walletBalance - 0.02).toStringAsFixed(2),
                    child: const Text('Max')),
                SizedBox(height: 16),
                // Send button
                ElevatedButton(
                  onPressed: sendHNS,
                  child: const Text('Send'),
                ),
              ],
            );
          },
        ),
      ),
    );
  }

  void sendHNS() {
    // Send HNS to the address
    String toAddress = addressController.text;
    double amount = double.parse(amountController.text);
    print('Send $amount HNS to $toAddress');
    if (amount > (walletBalance - 0.01)) {
      // Not enough balance
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(
          content: Text('Not enough balance'),
        ),
      );
      return;
    }
    bool sendMax = false;
    if (amount >= (walletBalance - 0.02)) {
      sendMax = true;
    }

    print(sendMax);
    // https://api.firewallet.au/wallet/send?uuid=99879737-0c27-497b-b357-f75720feb32e&name=hot&address=hs1qca9n20ew7ph6l5galfnftmwme6kwmu26mzjgtx&amount=2
    http
        .post(
      Uri.parse(
          'https://api.firewallet.au/wallet/send?uuid=${widget.uuid}&name=${widget.wallet}&address=$toAddress&amount=$amount'),
      headers: <String, String>{
        'Content-Type': 'application/json; charset=UTF-8',
      },
      body: '{}',
    )
        .then((response) {
      if (response.statusCode == 200) {
        final data = jsonDecode(response.body);
        print(data);
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('Sent $amount HNS to $toAddress'),
          ),
        );

        String seedPhrase = 'abandon abandon abandon abandon abandon abandon ' +
            'abandon abandon abandon abandon abandon about';
        print(hns.getXpub(seedPhrase));
        hns.signTX(seedPhrase, data).then((tx) {
          print(tx);
        });

        if (sendMax) {
          // amountController.text = '';
        } else {
          amountController.text =
              min(amount, walletBalance - 0.02).toStringAsFixed(2);
        }
        fetchWalletBalance();
      } else {
        // Handle error
        print('Failed to send HNS');
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(
            content: Text('Failed to send HNS'),
          ),
        );
      }
    });
  }
}