DatabaseKit Integration in BackendKit

import { getFirestore } from "firebase-admin/firestore";

// Get AI Chat Messages of the user that is currently logged in
export const retrieveCurrentUsersAIChatMessages = onCall(async (request) => {
  const fromUid = request.auth?.uid; // See AuthKit Integration
 
  if (!fromUid) {
    // ...
    throw new Error("User Not Logged In");
  }
 
  try {
    let messages = await getAIChatHistoryOfUserWithID(fromUid);
 
    // ...
 
    // get data from database. path:
    // "users" -> USER_ID -> "AIChatMessages" -> AUTO_ID -> {isFromUser: BOOL, messageContent: STRING, timestamp: TIMESTAMP}
    const snapshot = await getFirestore()
      .collection("users")
      .doc(user)
      .collection("AIChatMessages")
      .orderBy("timestamp", "asc") // we want the newest to be last
      .get();
 
    // define data structure that will be sent to the client
    let messages: {
      id: string; //id in database
      isFromUser: boolean; // true if from user, false if from GPT
      messageContent: string; // the actual message
      timestamp: string; // when the message was sent (ISO STRING)
    }[] = [];
 
    // go through each snapshot, and append the correct data to the messages array
    snapshot.forEach((doc) => {
      const data = doc.data();
      messages.push({
        id: doc.id,
        isFromUser: data.isFromUser,
        messageContent: data.messageContent,
        timestamp: data.timestamp.toDate().toISOString(),
      });
    });
 
    // ...
 
    return messages;
  } catch (error) {
    // ...
    throw new Error("Server Error");
  }
});