booster/firebase/firestore.rules

service cloud.firestore {
  match /databases/{database}/documents {
    // Util functions
    function userLoggedIn() {
      return request.auth != null
    }
    function isMe(userId) {
      return userLoggedIn() && request.auth.uid == userId
    }
    function includingMe(userIds) {
      return userLoggedIn() && request.auth.uid in userIds
    }
    function isAdmin() {
      return false
    }

    // User profiles
    match /userProfiles/{userId} {
      allow read;
      allow write: if isMe(userId)
    }
    match /userPrivateProfiles/{userId} {
      allow read, write: if isMe(userId)
    }
    match /userReadonlyProfiles/{userId} {
      allow read: if isMe(userId)
    }

    // Chat functions
    match /chats/{chatId} {
      allow read: if includingMe(resource.data.userIds)
      function isListedInChat() {
        return includingMe(get(/databases/$(database)/documents/chats/$(chatId)).data.userIds)
      }
      match /messages/{messageId} {
        allow create: if isListedInChat() && isMe(request.resource.data.createdBy)
        allow read: if isListedInChat()
      }
    }
  }
}