bitwindow: bid for FreeBank blocks

bitwindow/lib/main.dart

@@ -227,6 +227,10 @@ Future<(Directory, File, Logger)> init(String arguments) async {
   GetIt.I.registerSingleton<CoinShiftRPC>(CoinShiftLive());
   GetIt.I.registerSingleton<PhotonRPC>(PhotonLive());
   GetIt.I.registerSingleton<TruthcoinRPC>(TruthcoinLive());
+  GetIt.I.registerSingleton<FreeBankRPC>(FreeBankLive());
+  // FreeBank has no app of its own, so its BMM controls live in BitWindow. Lazy:
+  // the provider only starts watching the engine once the bid dialog opens.
+  GetIt.I.registerLazySingleton<BMMProvider>(() => BMMProvider(sidechainRPC: GetIt.I.get<FreeBankRPC>()));
 
   registerNodeMode();
 
@@ -257,6 +261,7 @@ Future<(Directory, File, Logger)> init(String arguments) async {
         GetIt.I.get<PhotonRPC>(),
         GetIt.I.get<TruthcoinRPC>(),
         GetIt.I.get<CoinShiftRPC>(),
+        GetIt.I.get<FreeBankRPC>(),
       ],
     ),
   );

bitwindow/lib/pages/sidechains_page.dart

@@ -9,6 +9,7 @@ import 'package:bitwindow/pages/sidechain_activation_management_page.dart';
 import 'package:bitwindow/providers/sidechain_provider.dart';
 import 'package:bitwindow/providers/transactions_provider.dart';
 import 'package:bitwindow/widgets/fast_withdrawal_tab.dart';
+import 'package:bitwindow/widgets/freebank_bid_dialog.dart';
 import 'package:bitwindow/widgets/starters_tab.dart';
 import 'package:collection/collection.dart';
 import 'package:flutter/foundation.dart';
@@ -615,6 +616,23 @@ class _SidechainActions extends StatelessWidget {
           ],
           _depositButton(context),
           const SizedBox(width: SailStyleValues.padding08),
+          if (viewModel.sidechainForSlot(slot) is FreeBank && settingsConnection != null) ...[
+            SizedBox.square(
+              dimension: 32,
+              child: SailTooltip(
+                message: 'Bid for FreeBank blocks',
+                child: SailButton(
+                  variant: ButtonVariant.icon,
+                  icon: SailSVGAsset.iconTabBmm,
+                  small: true,
+                  onPressed: () async {
+                    await showThemedDialog(context: context, builder: (context) => const FreeBankBidDialog());
+                  },
+                ),
+              ),
+            ),
+            const SizedBox(width: SailStyleValues.padding08),
+          ],
           SizedBox.square(
             dimension: 32,
             child: settingsConnection == null
@@ -736,6 +754,7 @@ class SidechainsViewModel extends BaseViewModel with ChangeTrackingMixin {
     Truthcoin() => SidechainType.SIDECHAIN_TYPE_TRUTHCOIN,
     Photon() => SidechainType.SIDECHAIN_TYPE_PHOTON,
     CoinShift() => SidechainType.SIDECHAIN_TYPE_COINSHIFT,
+    FreeBank() => SidechainType.SIDECHAIN_TYPE_FREEBANK,
     _ => null,
   };
 
@@ -898,6 +917,7 @@ class SidechainsViewModel extends BaseViewModel with ChangeTrackingMixin {
       var b when b is Truthcoin => GetIt.I.isRegistered<TruthcoinRPC>() ? GetIt.I.get<TruthcoinRPC>() : null,
       var b when b is Photon => GetIt.I.isRegistered<PhotonRPC>() ? GetIt.I.get<PhotonRPC>() : null,
       var b when b is CoinShift => GetIt.I.isRegistered<CoinShiftRPC>() ? GetIt.I.get<CoinShiftRPC>() : null,
+      var b when b is FreeBank => GetIt.I.isRegistered<FreeBankRPC>() ? GetIt.I.get<FreeBankRPC>() : null,
       _ => null,
     };
 
@@ -949,6 +969,7 @@ class SidechainsViewModel extends BaseViewModel with ChangeTrackingMixin {
       var b when b is Truthcoin => (GetIt.I.isRegistered<TruthcoinRPC>() ? GetIt.I.get<TruthcoinRPC>() : null),
       var b when b is Photon => (GetIt.I.isRegistered<PhotonRPC>() ? GetIt.I.get<PhotonRPC>() : null),
       var b when b is CoinShift => (GetIt.I.isRegistered<CoinShiftRPC>() ? GetIt.I.get<CoinShiftRPC>() : null),
+      var b when b is FreeBank => (GetIt.I.isRegistered<FreeBankRPC>() ? GetIt.I.get<FreeBankRPC>() : null),
       _ => null,
     };
   }
@@ -1645,6 +1666,7 @@ class _DepositModalState extends State<DepositModal> {
       ZSide() => GetIt.I.isRegistered<ZSideRPC>() ? GetIt.I.get<ZSideRPC>() : null,
       CoinShift() => GetIt.I.isRegistered<CoinShiftRPC>() ? GetIt.I.get<CoinShiftRPC>() : null,
       Thunder() => GetIt.I.isRegistered<ThunderRPC>() ? GetIt.I.get<ThunderRPC>() : null,
+      FreeBank() => GetIt.I.isRegistered<FreeBankRPC>() ? GetIt.I.get<FreeBankRPC>() : null,
       _ => null,
     };
 

bitwindow/lib/utils/freebank_conf.dart

@@ -0,0 +1,85 @@
+/// The one line of freebank.conf that BitWindow edits: `coinbasetag=`, the name
+/// a FreeBank node writes into the coinbase of every block it makes, so block
+/// explorers can credit the block to it. freebankd reads it at startup only.
+library;
+
+import 'dart:math';
+
+const coinbaseTagKey = 'coinbasetag';
+const coinbaseTagMaxBytes = 64;
+
+/// The name the conf gives, or null when it sets none. The last line wins, as in
+/// Core.
+String? readCoinbaseTag(String conf) {
+  String? tag;
+  for (final line in conf.split('\n')) {
+    final trimmed = line.trim();
+    if (trimmed.startsWith('$coinbaseTagKey=')) {
+      tag = trimmed.substring(coinbaseTagKey.length + 1).trim();
+    }
+  }
+  return tag;
+}
+
+/// Why freebankd would refuse this name, or null if it takes it. It mirrors the
+/// node's own check (1 to 64 printable ASCII bytes), plus the two things the conf
+/// file itself would bend: a `#` starts a comment, and quotes become part of the
+/// name.
+String? coinbaseTagProblem(String name) {
+  final tag = name.trim();
+  if (tag.isEmpty) {
+    return 'Give a name.';
+  }
+  if (tag.length > coinbaseTagMaxBytes) {
+    return 'Use at most $coinbaseTagMaxBytes characters.';
+  }
+  for (final unit in tag.codeUnits) {
+    if (unit < 0x20 || unit > 0x7e) {
+      return 'Use plain letters, digits, punctuation and spaces.';
+    }
+  }
+  if (tag.contains('#')) {
+    return 'Leave out #: it starts a comment in freebank.conf.';
+  }
+  if (tag.startsWith('"') || tag.startsWith("'") || tag.endsWith('"') || tag.endsWith("'")) {
+    return 'Leave out the quotes: they would become part of the name.';
+  }
+  return null;
+}
+
+/// The conf with its name set to [name]: an existing `coinbasetag=` line is
+/// replaced in place, and every other line is kept as it was.
+String setCoinbaseTag(String conf, String name) {
+  final line = '$coinbaseTagKey=${name.trim()}';
+  final lines = conf.isEmpty ? <String>[] : conf.split('\n');
+  final kept = <String>[];
+  var replaced = false;
+  for (final l in lines) {
+    if (l.trim().startsWith('$coinbaseTagKey=')) {
+      if (!replaced) {
+        kept.add(line);
+        replaced = true;
+      }
+      continue;
+    }
+    kept.add(l);
+  }
+  if (!replaced) {
+    if (kept.isNotEmpty && kept.last.isEmpty) {
+      kept.insert(kept.length - 1, line);
+    } else {
+      kept.add(line);
+    }
+  }
+  final out = kept.join('\n');
+  return out.endsWith('\n') ? out : '$out\n';
+}
+
+/// A name to offer a user who has none yet: unique enough to spot their own
+/// blocks, it says where they came from, and it carries nothing personal.
+String suggestCoinbaseTag([Random? random]) {
+  const letters = 'abcdefghjkmnpqrstuvwxyz23456789';
+  final rng = random ?? Random.secure();
+  final suffix = List.generate(4, (_) => letters[rng.nextInt(letters.length)]).join();
+  return 'bitwindow-$suffix';
+}

bitwindow/lib/widgets/freebank_bid_dialog.dart

@@ -0,0 +1,160 @@
+import 'dart:io';
+
+import 'package:bitwindow/utils/freebank_conf.dart';
+import 'package:flutter/material.dart';
+import 'package:get_it/get_it.dart';
+import 'package:logger/logger.dart';
+import 'package:sail_ui/pages/sidechains/bmm_tab.dart';
+import 'package:sail_ui/sail_ui.dart';
+
+/// Bidding for FreeBank blocks from BitWindow: the name the node writes into the
+/// blocks it wins, then the BMM engine's own controls. FreeBank has no app of its
+/// own, so BitWindow is where a user starts it.
+class FreeBankBidDialog extends StatefulWidget {
+  const FreeBankBidDialog({super.key});
+
+  @override
+  State<FreeBankBidDialog> createState() => _FreeBankBidDialogState();
+}
+
+class _FreeBankBidDialogState extends State<FreeBankBidDialog> {
+  final FreeBankRPC _rpc = GetIt.I.get<FreeBankRPC>();
+  final TextEditingController _name = TextEditingController();
+  String? _saved;
+  String? _error;
+  bool _saving = false;
+
+  bool get _hasName => _saved != null && _saved!.isNotEmpty;
+
+  File get _conf => File(filePath([_rpc.binary.datadirNetwork(), 'freebank.conf']));
+
+  @override
+  void initState() {
+    super.initState();
+    _load();
+  }
+
+  Future<void> _load() async {
+    try {
+      final conf = await _conf.exists() ? await _conf.readAsString() : '';
+      final tag = readCoinbaseTag(conf);
+      if (!mounted) {
+        return;
+      }
+      setState(() {
+        _saved = tag;
+        // A name is required before the first bid, so offer one to change.
+        _name.text = (tag == null || tag.isEmpty) ? suggestCoinbaseTag() : tag;
+      });
+    } catch (e) {
+      GetIt.I.get<Logger>().w('FreeBank: could not read freebank.conf: $e');
+    }
+  }
+
+  Future<void> _save() async {
+    final problem = coinbaseTagProblem(_name.text);
+    if (problem != null) {
+      setState(() => _error = problem);
+      return;
+    }
+    setState(() {
+      _error = null;
+      _saving = true;
+    });
+    try {
+      final conf = await _conf.exists() ? await _conf.readAsString() : '';
+      await _conf.parent.create(recursive: true);
+      await _conf.writeAsString(setCoinbaseTag(conf, _name.text));
+      // freebankd reads the name at startup only.
+      await GetIt.I.get<BinaryProvider>().restart(_rpc.binary);
+      if (!mounted) {
+        return;
+      }
+      setState(() => _saved = _name.text.trim());
+    } catch (e) {
+      if (!mounted) {
+        return;
+      }
+      setState(() => _error = 'Could not save the name: $e');
+    } finally {
+      if (mounted) {
+        setState(() => _saving = false);
+      }
+    }
+  }
+
+  @override
+  void dispose() {
+    _name.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = SailTheme.of(context);
+    return Dialog(
+      backgroundColor: Colors.transparent,
+      child: Container(
+        width: 760,
+        height: 720,
+        padding: const EdgeInsets.all(SailStyleValues.padding25),
+        decoration: BoxDecoration(
+          color: theme.colors.backgroundSecondary,
+          borderRadius: SailStyleValues.borderRadius,
+        ),
+        child: SailColumn(
+          spacing: SailStyleValues.padding16,
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            SailText.primary20('Bid for FreeBank blocks'),
+            SailText.secondary13(
+              'For each eCash block, your node offers a small fee to have its next FreeBank block included. '
+              'A bid is paid from your BitWindow wallet, and only when it wins.',
+            ),
+            SailText.primary13('Name on your blocks', bold: true),
+            SailRow(
+              spacing: SailStyleValues.padding08,
+              children: [
+                Expanded(
+                  child: SailTextField(
+                    controller: _name,
+                    hintText: "Your name, or your pool's name",
+                    enabled: !_saving,
+                  ),
+                ),
+                SailButton(
+                  label: 'Save',
+                  loading: _saving,
+                  onPressed: _save,
+                ),
+              ],
+            ),
+            SailText.secondary12(
+              _error ??
+                  (!_hasName
+                      ? 'Blocks you win show this name on the explorer. Change it if you like, then save. '
+                            'Saving restarts your FreeBank node.'
+                      : 'Blocks you win show "$_saved" on the explorer. Saving a new name restarts your FreeBank node.'),
+              color: _error == null ? null : theme.colors.error,
+            ),
+            Expanded(
+              // Every block a bid wins carries the name, so bidding waits for one.
+              child: _hasName
+                  ? const BMMTab()
+                  : Stack(
+                      children: [
+                        const IgnorePointer(child: Opacity(opacity: 0.35, child: BMMTab())),
+                        Center(child: SailText.primary15('Save a name above to start bidding.')),
+                      ],
+                    ),
+            ),
+            Align(
+              alignment: Alignment.centerRight,
+              child: SailButton(label: 'Close', onPressed: () async => Navigator.of(context).pop()),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}

bitwindow/test/deposit_modal_test.dart

@@ -112,6 +112,26 @@ void main() {
     expect(field.controller.text, 's9_pastedaddress_abc123');
   });
 
+  testWidgets('a running FreeBank leaves the address field open for a paste and says why', (tester) async {
+    GetIt.I.registerSingleton<FreeBankRPC>(FreeBankLive()..connected = true);
+    await GetIt.I.unregister<BinaryProvider>();
+    GetIt.I.registerSingleton<BinaryProvider>(
+      BinaryProvider.test(appDir: Directory.systemTemp, binaries: [FreeBank()]),
+    );
+
+    addTearDown(() => tester.pumpWidget(const SizedBox()));
+    await tester.pumpSailPage(const DepositModal(slot: 130, sidechainName: 'FreeBank'));
+    await tester.pump();
+
+    final field = tester.widget<SailTextField>(find.byType(SailTextField).first);
+    expect(field.readOnly, isFalse);
+    expect(field.controller.text, isEmpty);
+    expect(
+      find.text('Unsupported operation: fetching a FreeBank address. Paste one from your FreeBank wallet.'),
+      findsOneWidget,
+    );
+  });
+
   testWidgets('a pasted address with an amount arms the deposit button', (tester) async {
     await pumpModal(tester);