removeFavorite method
Removes exercise from favourites of a user.
Implementation
Future<void> removeFavorite(String email, String exerciseName) async {
final exerciseQuery = await firestore
.collection('exercises')
.where('name', isEqualTo: exerciseName)
.get();
if (exerciseQuery.docs.isEmpty) return;
final exerciseDoc = exerciseQuery.docs.first;
final exerciseRef = exerciseDoc.reference;
final userQuery = await firestore
.collection('users')
.where('email', isEqualTo: email)
.get();
if (userQuery.docs.isEmpty) return;
final userDoc = userQuery.docs.first;
final favoriteQuery = await userDoc.reference
.collection('favorites')
.where('exercise', isEqualTo: exerciseRef)
.get();
if (favoriteQuery.docs.isEmpty) return;
await favoriteQuery.docs.first.reference.delete();
}