firestore.rules

function validateContent(content) {
  return content != null && content.trim() != ''
}

service cloud.firestore {
  match /databases/{database}/documents {
    match /threads/{thread} {
     	allow read:
        if request.auth.uid != null;
     	allow create:
        if request.auth.uid != null
        && request.resource.data.board in ['cyb', 'psy', 'art', 'cult', 'tech', 'λ', 'Δ', 'φ']
        && request.resource.data.createdAt == request.time // not sure if correct
        && (
          !('image' in request.resource.data)
          || request.resource.data.image.matches('[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}')
        )
        && validateContent(request.resource.data.content);

      match /comments/{comment} {
        allow read:
        	if request.auth.uid != null;
        allow create:
          if request.auth.uid != null
          && request.resource.data.createdAt == request.time // not sure if correct
          && (
            !('image' in request.resource.data)
            || request.resource.data.image.matches('[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}')
          )
          && validateContent(request.resource.data.content);
      }
    }

    match /counters/{counter} {
    	allow read:
        if request.auth.uid != null;
      allow write:
      	if false;
    }
  }
}