Add comments on Filter goals

app/src/main/java/net/pokeranalytics/android/model/filter/Filterable.kt

@@ -3,6 +3,32 @@ package net.pokeranalytics.android.model.filter
 import io.realm.RealmObject
 import io.realm.RealmResults
 
+/**
+ * We want to be able to store filters in the database:
+ * - filters can be a combination of sub filters
+ * - filters can be applied to different type of objects: Sessions, Hands, Transactions...
+ * - filters can be applied to a list of different type of objects (feed)
+ *
+ * A filter is described by the following:
+ * - a data type: Session, Hands...
+ * - a field: table size of a Session
+ * - an operator: equal, >=, <...
+ * - a value: an id, a number, a date...
+ *
+ * We can decide to have a collection of [operator, value] for a field
+ *
+ * Combination:
+ * - multiple datatype filters should be handled as 'OR'
+ * - multiple field filters should be handled as 'AND'
+ * - multiple '=' filters as 'OR'
+ * - multiple 'Greater than', 'less than' as 'AND'
+ * - multiple values as 'OR'
+ *
+ * Also:
+ * A filter should be able to be converted into a Realm query
+ *
+ */
+
 interface Filterable {
 
 }