fix(llc, ui): message search pagination

Signed-off-by: xsahil03x <[email protected]>

packages/stream_chat/lib/src/core/api/general_api.dart

@@ -36,6 +36,10 @@ class GeneralApi {
     PaginationParams? pagination,
     Filter? messageFilters,
   }) async {
+    assert(
+      pagination?.offset == null || pagination?.offset == 0 || sort == null,
+      'Cannot specify `offset` with `sort` parameter',
+    );
     assert(() {
       if (query == null && messageFilters == null) {
         throw ArgumentError('Provide at least `query` or `messageFilters`');

packages/stream_chat/lib/src/core/api/requests.dart

@@ -60,12 +60,16 @@ class PaginationParams extends Equatable {
   /// ```
   const PaginationParams({
     this.limit = 10,
-    this.offset = 0,
+    this.offset,
+    this.next,
     this.greaterThan,
     this.greaterThanOrEqual,
     this.lessThan,
     this.lessThanOrEqual,
-  });
+  }) : assert(
+          offset == null || offset == 0 || next == null,
+          'Cannot specify non-zero `offset` with `next` parameter',
+        );
 
   /// Create a new instance from a json
   factory PaginationParams.fromJson(Map<String, dynamic> json) =>
@@ -75,7 +79,10 @@ class PaginationParams extends Equatable {
   final int limit;
 
   /// The offset of requesting items.
-  final int offset;
+  final int? offset;
+
+  /// A key used to paginate.
+  final String? next;
 
   /// Filter on ids greater than the given value.
   @JsonKey(name: 'id_gt')
@@ -100,6 +107,7 @@ class PaginationParams extends Equatable {
   PaginationParams copyWith({
     int? limit,
     int? offset,
+    String? next,
     String? greaterThan,
     String? greaterThanOrEqual,
     String? lessThan,
@@ -108,6 +116,7 @@ class PaginationParams extends Equatable {
       PaginationParams(
         limit: limit ?? this.limit,
         offset: offset ?? this.offset,
+        next: next ?? this.next,
         greaterThan: greaterThan ?? this.greaterThan,
         greaterThanOrEqual: greaterThanOrEqual ?? this.greaterThanOrEqual,
         lessThan: lessThan ?? this.lessThan,
@@ -118,6 +127,7 @@ class PaginationParams extends Equatable {
   List<Object?> get props => [
         limit,
         offset,
+        next,
         greaterThan,
         greaterThanOrEqual,
         lessThan,

packages/stream_chat/lib/src/core/api/requests.g.dart

@@ -23,6 +23,7 @@ PaginationParams _$PaginationParamsFromJson(Map<String, dynamic> json) {
   return PaginationParams(
     limit: json['limit'] as int,
     offset: json['offset'] as int,
+    next: json['next'] as String?,
     greaterThan: json['id_gt'] as String?,
     greaterThanOrEqual: json['id_gte'] as String?,
     lessThan: json['id_lt'] as String?,
@@ -42,6 +43,7 @@ Map<String, dynamic> _$PaginationParamsToJson(PaginationParams instance) {
     }
   }
 
+  writeNotNull('next', instance.next);
   writeNotNull('id_gt', instance.greaterThan);
   writeNotNull('id_gte', instance.greaterThanOrEqual);
   writeNotNull('id_lt', instance.lessThan);

packages/stream_chat/lib/src/core/api/responses.dart

@@ -253,6 +253,12 @@ class SearchMessagesResponse extends _BaseResponse {
   @JsonKey(defaultValue: [])
   late List<GetMessageResponse> results;
 
+  /// Message id of where to start searching from for next [results]
+  late String? next;
+
+  /// Message id of where to start searching from for previous [results]
+  late String? previous;
+
   /// Create a new instance from a json
   static SearchMessagesResponse fromJson(Map<String, dynamic> json) =>
       _$SearchMessagesResponseFromJson(json);

packages/stream_chat/lib/src/core/api/responses.g.dart

@@ -161,7 +161,9 @@ SearchMessagesResponse _$SearchMessagesResponseFromJson(
     ..results = (json['results'] as List<dynamic>?)
             ?.map((e) => GetMessageResponse.fromJson(e as Map<String, dynamic>))
             .toList() ??
-        [];
+        []
+    ..next = json['next'] as String?
+    ..previous = json['previous'] as String?;
 }
 
 GetMessagesByIdResponse _$GetMessagesByIdResponseFromJson(

packages/stream_chat/test/src/core/api/general_api_test.dart

@@ -86,6 +86,24 @@ void main() {
       },
     );
 
+    test(
+      'should throw if `pagination.offset` and `sort` both are provided',
+      () async {
+        final filter = Filter.in_('cid', const ['test-cid-1', 'test-cid-2']);
+        const sort = [SortOption<ChannelModel>('test-field')];
+        const pagination = PaginationParams(offset: 10);
+        try {
+          await generalApi.searchMessages(
+            filter,
+            sort: sort,
+            pagination: pagination,
+          );
+        } catch (e) {
+          expect(e, isA<AssertionError>());
+        }
+      },
+    );
+
     test('should run successfully with `query`', () async {
       final filter = Filter.in_('cid', const ['test-cid-1', 'test-cid-2']);
       const query = 'test-query';

packages/stream_chat/test/src/core/api/requests_test.dart

@@ -9,11 +9,23 @@ void main() {
       expect(j, {'field': 'name', 'direction': -1});
     });
 
-    test('PaginationParams', () {
-      const option = PaginationParams();
-      final j = option.toJson();
-      expect(j, containsPair('limit', 10));
-      expect(j, containsPair('offset', 0));
+    group('PaginationParams', () {
+      test('default', () {
+        const option = PaginationParams();
+        final j = option.toJson();
+        expect(j, containsPair('limit', 10));
+      });
+
+      test(
+        'should throw if non-zero `offset` and `next` both are provided',
+        () {
+          try {
+            PaginationParams(offset: 10, next: 'next-message-id');
+          } catch (e) {
+            expect(e, isA<AssertionError>());
+          }
+        },
+      );
     });
   });
 }

packages/stream_chat_flutter_core/lib/src/message_search_bloc.dart

@@ -43,6 +43,9 @@ class MessageSearchBlocState extends State<MessageSearchBloc>
     with AutomaticKeepAliveClientMixin {
   late StreamChatCoreState _streamChatCoreState;
 
+  String? nextId;
+  String? previousId;
+
   /// The current messages list
   List<GetMessageResponse>? get messageResponses =>
       _messageResponses.valueOrNull;
@@ -76,11 +79,17 @@ class MessageSearchBlocState extends State<MessageSearchBloc>
       _queryMessagesLoadingController.add(true);
     }
     try {
-      final clear = pagination == null || pagination.offset == 0;
+      var clear = pagination == null;
+      if (sort != null) {
+        clear |= pagination?.next == null;
+      } else {
+        final offset = pagination?.offset;
+        clear |= offset == null || offset == 0;
+      }
 
       final oldMessages = List<GetMessageResponse>.from(messageResponses ?? []);
 
-      final messages = await client.search(
+      final response = await client.search(
         filter,
         sort: sort,
         query: query,
@@ -88,10 +97,20 @@ class MessageSearchBlocState extends State<MessageSearchBloc>
         messageFilters: messageFilter,
       );
 
+      final next = response.next;
+      final previous = response.previous;
+
+      nextId = next != null && next.isNotEmpty
+          ? next
+          : /*reset nextId if we get nothing*/ null;
+      previousId = previous != null && previous.isNotEmpty
+          ? previous
+          : /*reset previousId if we get nothing*/ null;
+
       if (clear) {
-        _messageResponses.add(messages.results);
+        _messageResponses.add(response.results);
       } else {
-        final temp = oldMessages + messages.results;
+        final temp = oldMessages + response.results;
         _messageResponses.add(temp);
       }
       if (_messageResponses.hasValue && _queryMessagesLoadingController.value) {

packages/stream_chat_flutter_core/lib/src/message_search_list_core.dart

@@ -37,7 +37,7 @@ class MessageSearchListCore extends StatefulWidget {
   /// * [errorBuilder]
   /// * [loadingBuilder]
   /// * [childBuilder]
-  const MessageSearchListCore({
+  MessageSearchListCore({
     Key? key,
     required this.emptyBuilder,
     required this.errorBuilder,
@@ -49,7 +49,21 @@ class MessageSearchListCore extends StatefulWidget {
     this.paginationParams,
     this.messageFilters,
     this.messageSearchListController,
-  }) : super(key: key);
+  })  : assert(
+          messageQuery != null || messageFilters != null,
+          'Provide at least `query` or `messageFilters`',
+        ),
+        assert(
+          messageQuery == null || messageFilters == null,
+          "Can't provide both `query` and `messageFilters` at the same time",
+        ),
+        assert(
+          paginationParams?.offset == null ||
+              paginationParams?.offset == 0 ||
+              sortOptions == null,
+          'Cannot specify `offset` with `sortOptions` parameter',
+        ),
+        super(key: key);
 
   /// A [MessageSearchListController] allows reloading and pagination.
   /// Use [MessageSearchListController.loadData] and
@@ -73,9 +87,8 @@ class MessageSearchListCore extends StatefulWidget {
   final List<SortOption>? sortOptions;
 
   /// Pagination parameters
-  /// limit: the number of users to return (max is 30)
+  /// limit: the number of messages to return (max is 30)
   /// offset: the offset (max is 1000)
-  /// message_limit: how many messages should be included to each channel
   final PaginationParams? paginationParams;
 
   /// The message query filters to use.
@@ -159,15 +172,25 @@ class MessageSearchListCoreState extends State<MessageSearchListCore> {
       );
 
   /// Fetches more messages with updated pagination and updates the widget
-  Future<void> paginateData() => _messageSearchBloc!.search(
-        filter: widget.filters,
-        sort: widget.sortOptions,
-        pagination: widget.paginationParams!.copyWith(
-          offset: _messageSearchBloc!.messageResponses?.length ?? 0,
-        ),
-        query: widget.messageQuery,
-        messageFilter: widget.messageFilters,
+  Future<void> paginateData() {
+    PaginationParams? pagination;
+    if (widget.sortOptions != null) {
+      pagination = widget.paginationParams?.copyWith(
+        next: _messageSearchBloc?.nextId,
       );
+    } else {
+      pagination = widget.paginationParams?.copyWith(
+        offset: _messageSearchBloc?.messageResponses?.length,
+      );
+    }
+    return _messageSearchBloc!.search(
+      filter: widget.filters,
+      sort: widget.sortOptions,
+      pagination: pagination,
+      query: widget.messageQuery,
+      messageFilter: widget.messageFilters,
+    );
+  }
 
   @override
   void didUpdateWidget(MessageSearchListCore oldWidget) {

packages/stream_chat_persistence/lib/src/dao/channel_query_dao.dart

@@ -113,8 +113,9 @@ class ChannelQueryDao extends DatabaseAccessor<MoorChatDatabase>
 
     cachedChannels.sort(chainedComparator);
 
-    if (paginationParams?.offset != null && cachedChannels.isNotEmpty) {
-      cachedChannels.removeRange(0, paginationParams!.offset);
+    final offset = paginationParams?.offset;
+    if (offset != null && offset > 0 && cachedChannels.isNotEmpty) {
+      cachedChannels.removeRange(0, offset);
     }
 
     if (paginationParams?.limit != null) {

packages/stream_chat_persistence/lib/src/dao/message_dao.dart

@@ -117,8 +117,9 @@ class MessageDao extends DatabaseAccessor<MoorChatDatabase>
           msgList.removeRange(0, greaterThanIndex);
         }
       }
-      if (options?.limit != null) {
-        return msgList.take(options!.limit).toList();
+      final limit = options?.limit;
+      if (limit != null && limit > 0) {
+        return msgList.take(limit).toList();
       }
     }
     return msgList;