Integrate Open CryptoPay payment standard

lib/models/send_view_auto_fill_data.dart

@@ -10,17 +10,25 @@
 
 import 'package:decimal/decimal.dart';
 
+import '../services/open_crypto_pay/models.dart';
+
 class SendViewAutoFillData {
   final String address;
   final String contactLabel;
   final Decimal? amount;
   final String note;
 
+  /// When set, ConfirmTransactionView will notify the OpenCryptoPay provider
+  /// with the broadcast tx ID (and raw hex, where available) after a
+  /// successful send.
+  final OpenCryptoPayCommit? openCryptoPayCommit;
+
   SendViewAutoFillData({
     required this.address,
     required this.contactLabel,
     this.amount,
     this.note = "",
+    this.openCryptoPayCommit,
   });
 
   Map<String, dynamic> toJson() {

lib/pages/open_crypto_pay/open_crypto_pay_confirm_view.dart

@@ -0,0 +1,252 @@
+import 'dart:async';
+
+import 'package:decimal/decimal.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:tuple/tuple.dart';
+
+import '../../models/send_view_auto_fill_data.dart';
+import '../../notifications/show_flush_bar.dart';
+import '../../services/open_crypto_pay/models.dart';
+import '../../services/open_crypto_pay/open_crypto_pay_api.dart';
+import '../../themes/stack_colors.dart';
+import '../../utilities/address_utils.dart';
+import '../../utilities/logger.dart';
+import '../../utilities/text_styles.dart';
+import '../../wallets/crypto_currency/crypto_currency.dart';
+import '../../widgets/background.dart';
+import '../../widgets/custom_buttons/app_bar_icon_button.dart';
+import '../../widgets/desktop/primary_button.dart';
+import '../../widgets/loading_indicator.dart';
+import '../../widgets/rounded_white_container.dart';
+import '../send_view/send_view.dart';
+
+/// Fetches the transaction details for the selected method/asset, shows a
+/// summary, then forwards to the standard [SendView] prefilled with the
+/// payment address and amount.
+class OpenCryptoPayConfirmView extends ConsumerStatefulWidget {
+  const OpenCryptoPayConfirmView({
+    super.key,
+    required this.paymentDetails,
+    required this.selectedMethod,
+    required this.selectedAsset,
+    required this.walletId,
+    required this.coin,
+  });
+
+  final OpenCryptoPayPaymentDetails paymentDetails;
+  final OpenCryptoPayTransferMethod selectedMethod;
+  final OpenCryptoPayAsset selectedAsset;
+  final String walletId;
+  final CryptoCurrency coin;
+
+  @override
+  ConsumerState<OpenCryptoPayConfirmView> createState() =>
+      _OpenCryptoPayConfirmViewState();
+}
+
+class _OpenCryptoPayConfirmViewState
+    extends ConsumerState<OpenCryptoPayConfirmView> {
+  OpenCryptoPayTransactionDetails? _txDetails;
+  bool _isLoading = true;
+  String? _errorMessage;
+
+  @override
+  void initState() {
+    super.initState();
+    _fetch();
+  }
+
+  Future<void> _fetch() async {
+    setState(() {
+      _isLoading = true;
+      _errorMessage = null;
+    });
+
+    try {
+      _txDetails = await OpenCryptoPayApi.instance.getTransactionDetails(
+        callbackUrl: widget.paymentDetails.callback,
+        quoteId: widget.paymentDetails.quote!.id,
+        method: widget.selectedMethod.method,
+        asset: widget.selectedAsset.asset,
+      );
+    } catch (e, s) {
+      Logging.instance.e("OpenCryptoPay tx fetch failed", error: e, stackTrace: s);
+      _errorMessage = 'Failed to fetch transaction details: $e';
+    } finally {
+      if (mounted) setState(() => _isLoading = false);
+    }
+  }
+
+  /// Parses address and amount from the transaction URI. Strips the EVM
+  /// `@chainId` suffix that [AddressUtils] leaves attached.
+  ({String? address, Decimal? amount}) _parseTransactionUri(String uri) {
+    final data = AddressUtils.parsePaymentUri(uri, logging: Logging.instance);
+    var address = data?.address ?? Uri.tryParse(uri)?.path;
+    if (address != null) {
+      final at = address.indexOf('@');
+      if (at != -1) address = address.substring(0, at);
+      if (address.isEmpty) address = null;
+    }
+    final amount = data?.amount != null
+        ? Decimal.tryParse(data!.amount!)
+        : Decimal.tryParse(widget.selectedAsset.amount);
+    return (address: address, amount: amount);
+  }
+
+  Future<void> _proceedToSend() async {
+    final uri = _txDetails?.uri;
+    if (uri == null) {
+      _warn("No transaction URI provided by the payment provider");
+      return;
+    }
+
+    final parsed = _parseTransactionUri(uri);
+    if (parsed.address == null) {
+      _warn("Could not parse payment address");
+      return;
+    }
+
+    final recipient = widget.paymentDetails.recipient?.name ??
+        widget.paymentDetails.displayName ??
+        "OpenCryptoPay";
+
+    if (!mounted) return;
+    await Navigator.of(context).pushNamed(
+      SendView.routeName,
+      arguments: Tuple3(
+        widget.walletId,
+        widget.coin,
+        SendViewAutoFillData(
+          address: parsed.address!,
+          contactLabel: recipient,
+          amount: parsed.amount,
+          note: "OpenCryptoPay: $recipient",
+          openCryptoPayCommit: OpenCryptoPayCommit(
+            callbackUrl: widget.paymentDetails.callback,
+            quoteId: widget.paymentDetails.quote!.id,
+            method: widget.selectedMethod.method,
+            asset: widget.selectedAsset.asset,
+          ),
+        ),
+      ),
+    );
+  }
+
+  void _warn(String message) {
+    unawaited(
+      showFloatingFlushBar(
+        type: FlushBarType.warning,
+        message: message,
+        context: context,
+      ),
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Background(
+      child: Scaffold(
+        backgroundColor:
+            Theme.of(context).extension<StackColors>()!.background,
+        appBar: AppBar(
+          backgroundColor:
+              Theme.of(context).extension<StackColors>()!.backgroundAppBar,
+          leading: const AppBarBackButton(),
+          title: Text(
+            "Confirm Payment",
+            style: STextStyles.navBarTitle(context),
+          ),
+        ),
+        body: SafeArea(
+          child: Padding(padding: const EdgeInsets.all(16), child: _body()),
+        ),
+      ),
+    );
+  }
+
+  Widget _body() {
+    if (_isLoading) return const Center(child: LoadingIndicator());
+
+    if (_errorMessage != null) {
+      return Center(
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: [
+            Text(
+              _errorMessage!,
+              style: STextStyles.itemSubtitle(context),
+              textAlign: TextAlign.center,
+            ),
+            const SizedBox(height: 16),
+            PrimaryButton(label: "Retry", onPressed: _fetch),
+          ],
+        ),
+      );
+    }
+
+    final details = widget.paymentDetails;
+    return SingleChildScrollView(
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.stretch,
+        children: [
+          RoundedWhiteContainer(
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                Text(
+                  "Payment Summary",
+                  style: STextStyles.itemSubtitle12(context),
+                ),
+                const SizedBox(height: 8),
+                if (details.recipient?.name != null)
+                  _row("To", details.recipient!.name!),
+                if (details.requestedAmount != null)
+                  _row(
+                    "Fiat amount",
+                    "${details.requestedAmount!.amount} "
+                        "${details.requestedAmount!.asset}",
+                  ),
+                _row(
+                  "Crypto amount",
+                  "${widget.selectedAsset.amount} "
+                      "${widget.selectedAsset.asset}",
+                ),
+                _row("Network", widget.selectedMethod.method),
+              ],
+            ),
+          ),
+          if (_txDetails?.hint != null) ...[
+            const SizedBox(height: 16),
+            RoundedWhiteContainer(
+              child: Text(_txDetails!.hint!, style: STextStyles.label(context)),
+            ),
+          ],
+          const SizedBox(height: 24),
+          PrimaryButton(label: "Proceed to Send", onPressed: _proceedToSend),
+        ],
+      ),
+    );
+  }
+
+  Widget _row(String label, String value) {
+    return Padding(
+      padding: const EdgeInsets.only(bottom: 4),
+      child: Row(
+        children: [
+          SizedBox(
+            width: 100,
+            child: Text(label, style: STextStyles.label(context)),
+          ),
+          Expanded(
+            child: Text(
+              value,
+              style: STextStyles.itemSubtitle(context),
+              overflow: TextOverflow.ellipsis,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}