export const messageThreadSelectorWithThread:()

in packages/chat-component-bindings/src/messageThreadSelector.ts [313:375]
48 lines of code
11 McCabe index (conditional complexity)

export const messageThreadSelectorWithThread: () => MessageThreadSelector = () =>
  createSelector(
    [getUserId, getChatMessages, getLatestReadTime, getIsLargeGroup, getReadReceipts, getParticipants],
    (userId, chatMessages, latestReadTime, isLargeGroup, readReceipts = [], participants) => {
      // We can't get displayName in teams meeting interop for now, disable rr feature when it is teams interop
      const isTeamsInterop = Object.values(participants).find((p) => 'microsoftTeamsUserId' in p.id) !== undefined;

      // get number of participants
      // filter out the non valid participants (no display name)
      // Read Receipt details will be disabled when participant count is 0
      const participantCount = isTeamsInterop
        ? undefined
        : Object.values(participants).filter((p) => p.displayName && p.displayName !== '').length;

      // creating key value pairs of senderID: last read message information

      const readReceiptsBySenderId: ReadReceiptsBySenderId = {};

      // readReceiptsBySenderId[senderID] gets updated every time a new message is read by this sender
      // in this way we can make sure that we are only saving the latest read message id and read on time for each sender
      readReceipts
        .filter((r) => r.sender && toFlatCommunicationIdentifier(r.sender) !== userId)
        .forEach((r) => {
          readReceiptsBySenderId[toFlatCommunicationIdentifier(r.sender)] = {
            lastReadMessage: r.chatMessageId,
            displayName: participants[toFlatCommunicationIdentifier(r.sender)]?.displayName ?? ''
          };
        });

      // A function takes parameter above and generate return value
      const convertedMessages = memoizedAllConvertChatMessage((memoizedFn) =>
        Object.values(chatMessages)
          .filter(
            (message) =>
              message.type.toLowerCase() === ACSKnownMessageType.text ||
              message.type.toLowerCase() === ACSKnownMessageType.richtextHtml ||
              message.type.toLowerCase() === ACSKnownMessageType.html ||
              (message.type === ACSKnownMessageType.participantAdded && hasValidParticipant(message)) ||
              (message.type === ACSKnownMessageType.participantRemoved && hasValidParticipant(message)) ||
              // TODO: Add support for topicUpdated system messages in MessageThread component.
              // message.type === ACSKnownMessageType.topicUpdated ||
              message.clientMessageId !== undefined
          )
          .filter(isMessageValidToRender)
          .map((message) => {
            return memoizedFn(
              message.id ?? message.clientMessageId,
              message,
              userId,
              message.createdOn <= latestReadTime,
              isLargeGroup
            );
          })
      );
      updateMessagesWithAttached(convertedMessages);
      return {
        userId,
        showMessageStatus: true,
        messages: convertedMessages,
        participantCount,
        readReceiptsBySenderId
      };
    }