firestore.rules

rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read, write: if false;
    }
    
    match /cards/{doc} {
    	allow read: if isSignedIn();
      allow write: if isSignedIn() && request.auth.uid == request.resource.data.uid;
      allow delete, update: if isSignedIn() && request.auth.uid == getCard(doc).data.uid;
    }

    match /users/{doc} {
      allow read: if isSignedIn();
      allow write: if isSignedIn() && request.auth.uid == doc;
    }

    match /friends/{doc} {
      allow read: if isSignedIn();
      allow write: if isSignedIn() && 
        (request.auth.uid == request.resource.data.uid1 || request.auth.uid == request.resource.data.uid2) &&
        request.resource.data.uid1 != request.resource.data.uid2;
    }
    
    function getCard(doc) {
    	return get(/databases/$(database)/documents/cards/$(doc));
    }

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