autocomplete: Support @-wildcard in user-mention autocomplete

Fixes: zulip#234

assets/l10n/app_en.arb

@@ -543,6 +543,41 @@
   "@manyPeopleTyping": {
     "description": "Text to display when there are multiple users typing."
   },
+  "all": "all",
+  "@all": {
+    "description": "Text for \"@all\" wildcard mention."
+  },
+  "everyone": "everyone",
+  "@everyone": {
+    "description": "Text for \"@everyone\" wildcard mention."
+  },
+  "channel": "channel",
+  "@channel": {
+    "description": "Text for \"@channel\" wildcard mention."
+  },
+  "stream": "stream",
+  "@stream": {
+    "description": "Text for \"@stream\" wildcard mention."
+  },
+  "topic": "topic",
+  "@topic": {
+    "description": "Text for \"@topic\" wildcard mention."
+  },
+  "notifyChannel": "Notify {value, select, channel{channel} other{stream}}",
+  "@notifyChannel": {
+    "description": "Description for \"@all\", \"@everyone\", \"@channel\", and \"@stream\" wildcard mentions in a channel or topic narrow.",
+    "placeholders": {
+      "value": {"type": "String"}
+    }
+  },
+  "notifyRecipients": "Notify recipients",
+  "@notifyRecipients": {
+    "description": "Description for \"@all\" and \"@everyone\" wildcard mentions in a DM narrow."
+  },
+  "notifyTopic": "Notify topic",
+  "@notifyTopic": {
+    "description": "Description for \"@topic\" wildcard mention in a channel or topic narrow."
+  },
   "messageIsEditedLabel": "EDITED",
   "@messageIsEditedLabel": {
     "description": "Label for an edited message. (Use ALL CAPS for cased alphabets: Latin, Greek, Cyrillic, etc.)"

lib/model/autocomplete.dart

@@ -288,42 +288,29 @@ class MentionAutocompleteView extends AutocompleteView<MentionAutocompleteQuery,
   MentionAutocompleteView._({
     required super.store,
     required this.narrow,
+    required this.wildcards,
     required this.sortedUsers,
   });
 
   factory MentionAutocompleteView.init({
     required PerAccountStore store,
     required Narrow narrow,
+    required List<Wildcard> wildcards,
   }) {
     final view = MentionAutocompleteView._(
       store: store,
       narrow: narrow,
+      wildcards: wildcards,
       sortedUsers: _usersByRelevance(store: store, narrow: narrow),
     );
     store.autocompleteViewManager.registerMentionAutocomplete(view);
     return view;
   }
 
   final Narrow narrow;
+  final List<Wildcard> wildcards;
   final List<User> sortedUsers;
 
-  @override
-  Future<List<MentionAutocompleteResult>?> computeResults() async {
-    final results = <MentionAutocompleteResult>[];
-    if (await filterCandidates(filter: _testUser,
-          candidates: sortedUsers, results: results)) {
-      return null;
-    }
-    return results;
-  }
-
-  MentionAutocompleteResult? _testUser(MentionAutocompleteQuery query, User user) {
-    if (query.testUser(user, store.autocompleteViewManager.autocompleteDataCache)) {
-      return UserMentionAutocompleteResult(userId: user.userId);
-    }
-    return null;
-  }
-
   static List<User> _usersByRelevance({
     required PerAccountStore store,
     required Narrow narrow,
@@ -377,8 +364,6 @@ class MentionAutocompleteView extends AutocompleteView<MentionAutocompleteQuery,
     required String? topic,
     required PerAccountStore store,
   }) {
-    // TODO(#234): give preference to "all", "everyone" or "stream"
-
     // TODO(#618): give preference to subscribed users first
 
     if (streamId != null) {
@@ -483,6 +468,42 @@ class MentionAutocompleteView extends AutocompleteView<MentionAutocompleteQuery,
     return userAName.compareTo(userBName); // TODO(i18n): add locale-aware sorting
   }
 
+  bool _isChannelWildcardIncluded = false;
+
+  @override
+  Future<List<MentionAutocompleteResult>?> computeResults() async {
+    _isChannelWildcardIncluded = false;
+    final results = <MentionAutocompleteResult>[];
+    // give priority to wildcard mentions
+    if (await filterCandidates(filter: _testWildcard,
+        candidates: wildcards, results: results)) {
+      return null;
+    }
+    if (await filterCandidates(filter: _testUser,
+        candidates: sortedUsers, results: results)) {
+      return null;
+    }
+    return results;
+  }
+
+  MentionAutocompleteResult? _testWildcard(MentionAutocompleteQuery query, Wildcard wildcard) {
+    if (query.testWildcard(wildcard)) {
+      if (wildcard.type == WildcardType.channel) {
+        if (_isChannelWildcardIncluded) return null;
+        _isChannelWildcardIncluded = true;
+      }
+      return WildcardMentionAutocompleteResult(wildcardName: wildcard.name);
+    }
+    return null;
+  }
+
+  MentionAutocompleteResult? _testUser(MentionAutocompleteQuery query, User user) {
+    if (query.testUser(user, store.autocompleteViewManager.autocompleteDataCache)) {
+      return UserMentionAutocompleteResult(userId: user.userId);
+    }
+    return null;
+  }
+
   @override
   void dispose() {
     store.autocompleteViewManager.unregisterMentionAutocomplete(this);
@@ -493,6 +514,37 @@ class MentionAutocompleteView extends AutocompleteView<MentionAutocompleteQuery,
   }
 }
 
+class Wildcard {
+  Wildcard({
+    required this.name,
+    required this.value,
+    required this.fullDisplayName,
+    required this.type,
+  });
+
+  /// The name of the wildcard to be shown as part of [fullDisplayName] in autocomplete suggestions.
+  ///
+  /// Ex: "channel", "stream", "topic", ...
+  final String name;
+
+  /// The value to be put at the compose box after choosing an option from autocomplete.
+  ///
+  /// Same as the [name], except for "stream" it is "channel" in FL >= 247 (server-9).
+  final String value; // TODO(sever-9): remove, instead use [name]
+
+  /// The full name of the wildcard to be shown in autocomplete suggestions.
+  ///
+  /// Ex: "all (Notify channel)" or "everyone (Notify recipients)".
+  final String fullDisplayName;
+
+  final WildcardType type;
+}
+
+enum WildcardType {
+  channel,
+  topic, // TODO(sever-8)
+}
+
 abstract class AutocompleteQuery {
   AutocompleteQuery(this.raw)
     : _lowercaseWords = raw.toLowerCase().split(' ');
@@ -529,15 +581,14 @@ class MentionAutocompleteQuery extends AutocompleteQuery {
   /// Whether the user wants a silent mention (@_query, vs. @query).
   final bool silent;
 
-  bool testUser(User user, AutocompleteDataCache cache) {
-    // TODO(#236) test email too, not just name
+  bool testWildcard(Wildcard wildcard) {
+    return wildcard.name.contains(raw.toLowerCase());
+  }
 
+  bool testUser(User user, AutocompleteDataCache cache) {
     if (!user.isActive) return false;
 
-    return _testName(user, cache);
-  }
-
-  bool _testName(User user, AutocompleteDataCache cache) {
+    // TODO(#236) test email too, not just name
     return _testContainsQueryWords(cache.nameWordsForUser(user));
   }
 
@@ -585,9 +636,13 @@ class UserMentionAutocompleteResult extends MentionAutocompleteResult {
   final int userId;
 }
 
-// TODO(#233): // class UserGroupMentionAutocompleteResult extends MentionAutocompleteResult {
+class WildcardMentionAutocompleteResult extends MentionAutocompleteResult {
+  WildcardMentionAutocompleteResult({required this.wildcardName});
+
+  final String wildcardName;
+}
 
-// TODO(#234): // class WildcardMentionAutocompleteResult extends MentionAutocompleteResult {
+// TODO(#233): // class UserGroupMentionAutocompleteResult extends MentionAutocompleteResult {
 
 class TopicAutocompleteView extends AutocompleteView<TopicAutocompleteQuery, TopicAutocompleteResult> {
   TopicAutocompleteView._({required super.store, required this.streamId});

lib/model/compose.dart

@@ -101,18 +101,21 @@ String wrapWithBacktickFence({required String content, String? infoString}) {
   return resultBuffer.toString();
 }
 
-/// An @-mention, like @**Chris Bobbe|13313**.
+/// An @user-mention, like @**Chris Bobbe|13313**.
 ///
 /// To omit the user ID part ("|13313") whenever the name part is unambiguous,
 /// pass a Map of all users we know about. This means accepting a linear scan
 /// through all users; avoid it in performance-sensitive codepaths.
-String mention(User user, {bool silent = false, Map<int, User>? users}) {
+String userMention(User user, {bool silent = false, Map<int, User>? users}) {
   bool includeUserId = users == null
     || users.values.where((u) => u.fullName == user.fullName).take(2).length == 2;
 
   return '@${silent ? '_' : ''}**${user.fullName}${includeUserId ? '|${user.userId}' : ''}**';
 }
 
+/// An @wildcard-mention, like @**channel**.
+String wildcardMention(String wildcard) => '@**$wildcard**';
+
 /// https://spec.commonmark.org/0.30/#inline-link
 ///
 /// The "link text" is made by enclosing [visibleText] in square brackets.
@@ -145,7 +148,7 @@ String quoteAndReplyPlaceholder(PerAccountStore store, {
     SendableNarrow.ofMessage(message, selfUserId: store.selfUserId),
     nearMessageId: message.id);
   // See note in [quoteAndReply] about asking `mention` to omit the |<id> part.
-  return '${mention(sender!, silent: true)} ${inlineLink('said', url)}: ' // TODO(i18n) ?
+  return '${userMention(sender!, silent: true)} ${inlineLink('said', url)}: ' // TODO(i18n) ?
     '*(loading message ${message.id})*\n'; // TODO(i18n) ?
 }
 
@@ -169,6 +172,6 @@ String quoteAndReply(PerAccountStore store, {
     // Could ask `mention` to omit the |<id> part unless the mention is ambiguous…
     // but that would mean a linear scan through all users, and the extra noise
     // won't much matter with the already probably-long message link in there too.
-    return '${mention(sender!, silent: true)} ${inlineLink('said', url)}:\n' // TODO(i18n) ?
+    return '${userMention(sender!, silent: true)} ${inlineLink('said', url)}:\n' // TODO(i18n) ?
       '${wrapWithBacktickFence(content: rawContent, infoString: 'quote')}';
 }

lib/widgets/autocomplete.dart

@@ -1,6 +1,9 @@
 import 'package:flutter/material.dart';
+import 'package:flutter_gen/gen_l10n/zulip_localizations.dart';
 
+import '../model/store.dart';
 import 'content.dart';
+import 'icons.dart';
 import 'store.dart';
 import '../model/autocomplete.dart';
 import '../model/compose.dart';
@@ -164,7 +167,54 @@ class ComposeAutocomplete extends AutocompleteField<MentionAutocompleteQuery, Me
   @override
   MentionAutocompleteView initViewModel(BuildContext context) {
     final store = PerAccountStoreWidget.of(context);
-    return MentionAutocompleteView.init(store: store, narrow: narrow);
+    return MentionAutocompleteView.init(store: store, narrow: narrow, wildcards: _wildcards(context, store));
+  }
+
+  List<Wildcard> _wildcards(BuildContext context, PerAccountStore store) {
+    final isDmNarrow = narrow is DmNarrow;
+    final isChannelWildcardAvailable = store.account.zulipFeatureLevel >= 247; // TODO(server-9)
+    final isTopicWildcardAvailable = store.account.zulipFeatureLevel >= 188; // TODO(sever-8)
+    final zulipLocalizations = ZulipLocalizations.of(context);
+    return [
+      Wildcard(
+        name: zulipLocalizations.all,
+        value: 'all',
+        fullDisplayName: 'all (${isDmNarrow
+          ? zulipLocalizations.notifyRecipients
+          : zulipLocalizations.notifyChannel(isChannelWildcardAvailable
+              ? "channel" : "stream")})',
+        type: WildcardType.channel,
+      ),
+      Wildcard(
+        name: zulipLocalizations.everyone,
+        value: 'everyone',
+        fullDisplayName: 'everyone (${isDmNarrow
+          ? zulipLocalizations.notifyRecipients
+          : zulipLocalizations.notifyChannel(isChannelWildcardAvailable
+              ? "channel" : "stream")})',
+        type: WildcardType.channel,
+      ),
+      if (!isDmNarrow) ...[
+        if (isChannelWildcardAvailable) Wildcard(
+          name: zulipLocalizations.channel,
+          value: 'channel',
+          fullDisplayName: 'channel (${zulipLocalizations.notifyChannel('channel')})',
+          type: WildcardType.channel,
+        ),
+        Wildcard(
+          name: zulipLocalizations.stream,
+          value: isChannelWildcardAvailable ? 'channel' : 'stream',
+          fullDisplayName: 'stream (${zulipLocalizations.notifyChannel(isChannelWildcardAvailable ? 'channel' : 'stream')})',
+          type: WildcardType.channel,
+        ),
+        if (isTopicWildcardAvailable) Wildcard(
+          name: zulipLocalizations.topic,
+          value: 'topic',
+          fullDisplayName: 'topic (${zulipLocalizations.notifyTopic})',
+          type: WildcardType.topic,
+        ),
+      ],
+    ];
   }
 
   void _onTapOption(BuildContext context, MentionAutocompleteResult option) {
@@ -182,7 +232,9 @@ class ComposeAutocomplete extends AutocompleteField<MentionAutocompleteQuery, Me
       case UserMentionAutocompleteResult(:var userId):
         // TODO(i18n) language-appropriate space character; check active keyboard?
         //   (maybe handle centrally in `controller`)
-        replacementString = '${mention(store.users[userId]!, silent: intent.query.silent, users: store.users)} ';
+        replacementString = '${userMention(store.users[userId]!, silent: intent.query.silent, users: store.users)} ';
+      case WildcardMentionAutocompleteResult(:var wildcardName):
+        replacementString = '${wildcardMention(_wildcards(context, store).singleWhere((w) => w.name == wildcardName).value)} ';
     }
 
     controller.value = intent.textEditingValue.replaced(
@@ -195,12 +247,17 @@ class ComposeAutocomplete extends AutocompleteField<MentionAutocompleteQuery, Me
 
   @override
   Widget buildItem(BuildContext context, int index, MentionAutocompleteResult option) {
+    final store = PerAccountStoreWidget.of(context);
     Widget avatar;
     String label;
     switch (option) {
       case UserMentionAutocompleteResult(:var userId):
-        avatar = Avatar(userId: userId, size: 32, borderRadius: 3);
-        label = PerAccountStoreWidget.of(context).users[userId]!.fullName;
+        avatar = Avatar(userId: userId, size: 32, borderRadius: 3); // web uses 21px
+        label = store.users[userId]!.fullName;
+      case WildcardMentionAutocompleteResult(:var wildcardName):
+        avatar = const Icon(ZulipIcons.bullhorn, size: 29); // web uses 19px
+        print('wildcard name: $wildcardName');
+        label = _wildcards(context, store).singleWhere((w) => w.name == wildcardName).fullDisplayName;
     }
     return InkWell(
       onTap: () {

test/model/compose_test.dart

@@ -319,25 +319,25 @@ hello
   group('mention', () {
     final user = eg.user(userId: 123, fullName: 'Full Name');
     test('not silent', () {
-      check(mention(user, silent: false)).equals('@**Full Name|123**');
+      check(userMention(user, silent: false)).equals('@**Full Name|123**');
     });
     test('silent', () {
-      check(mention(user, silent: true)).equals('@_**Full Name|123**');
+      check(userMention(user, silent: true)).equals('@_**Full Name|123**');
     });
     test('`users` passed; has two users with same fullName', () async {
       final store = eg.store();
       await store.addUsers([user, eg.user(userId: 5), eg.user(userId: 234, fullName: user.fullName)]);
-      check(mention(user, silent: true, users: store.users)).equals('@_**Full Name|123**');
+      check(userMention(user, silent: true, users: store.users)).equals('@_**Full Name|123**');
     });
     test('`users` passed; has two same-name users but one of them is deactivated', () async {
       final store = eg.store();
       await store.addUsers([user, eg.user(userId: 5), eg.user(userId: 234, fullName: user.fullName, isActive: false)]);
-      check(mention(user, silent: true, users: store.users)).equals('@_**Full Name|123**');
+      check(userMention(user, silent: true, users: store.users)).equals('@_**Full Name|123**');
     });
     test('`users` passed; user has unique fullName', () async {
       final store = eg.store();
       await store.addUsers([user, eg.user(userId: 234, fullName: 'Another Name')]);
-      check(mention(user, silent: true, users: store.users)).equals('@_**Full Name**');
+      check(userMention(user, silent: true, users: store.users)).equals('@_**Full Name**');
     });
   });
 

test/widgets/autocomplete_test.dart

@@ -148,7 +148,7 @@ void main() {
       await tester.tap(find.text('User Three'));
       await tester.pump();
       check(tester.widget<TextField>(composeInputFinder).controller!.text)
-        .contains(mention(user3, users: store.users));
+        .contains(userMention(user3, users: store.users));
       checkUserShown(user1, store, expected: false);
       checkUserShown(user2, store, expected: false);
       checkUserShown(user3, store, expected: false);