firestore.rules

rules_version = '2';

service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read;
    }

    match /users {
      match /{userId} {
        allow write:if true
          && request.auth.uid == userId
          && validateString(incomingData().displayName, 0, 512)
          && validateString(incomingData().photoUrl, 0, 512)
          && validateString(incomingData().username, 0, 512)
        ;
      }
    }

    match /posts {
      match /{postId} {
        allow create: if true
          && request.auth.uid == incomingData().userId
          && validateString(incomingData().title, 0, 512)
          && validateString(incomingData().subtitle, 0, 512)
          && validateString(incomingData().hashtag, 0, 140)
          && validateString(incomingData().nodeTree, 0, 16384)
        ;
        allow update: if true
          && request.auth.uid == existingData().userId
          && request.auth.uid == incomingData().userId
          && validateString(incomingData().title, 0, 512)
          && validateString(incomingData().subtitle, 0, 512)
          && validateString(incomingData().nodeTree, 0, 16384)
          && incomingData().createdAt == existingData().createdAt
        allow delete: if request.auth.uid == existingData().userId
        ;
      }
    }

    match /tags {
      match /{tagId} {
        allow write: if true
          && isUserAuthenticated()
          && validateString(incomingData().text, 0, 512)
      }
    }
  }

  function incomingData() {
    return request.resource.data;
  }

  function existingData() {
    return resource.data;
  }

  function validateString(text, min, max) {
    return text is string && min <= text.size() && text.size() <= max;
  }

  function isUserAuthenticated() {
		return request.auth != null;
	}
}