fix: move v2 pkgs (#1331)

* fix: move eventstore pkgs

* fix: move eventstore pkgs

* fix: remove v2 view

* fix: remove v2 view

internal/eventstore/write_model.go

@@ -0,0 +1,43 @@
+package eventstore
+
+import "time"
+
+//MemberWriteModel is the minimum representation of a command side view model.
+// It implements a basic reducer
+// it's purpose is to reduce events to create new ones
+type WriteModel struct {
+	AggregateID       string        `json:"-"`
+	ProcessedSequence uint64        `json:"-"`
+	Events            []EventReader `json:"-"`
+	ResourceOwner     string        `json:"-"`
+	ChangeDate        time.Time     `json:"-"`
+}
+
+//AppendEvents adds all the events to the read model.
+// The function doesn't compute the new state of the read model
+func (rm *WriteModel) AppendEvents(events ...EventReader) {
+	rm.Events = append(rm.Events, events...)
+}
+
+//Reduce is the basic implementaion of reducer
+// If this function is extended the extending function should be the last step
+func (wm *WriteModel) Reduce() error {
+	if len(wm.Events) == 0 {
+		return nil
+	}
+
+	if wm.AggregateID == "" {
+		wm.AggregateID = wm.Events[0].Aggregate().ID
+	}
+	if wm.ResourceOwner == "" {
+		wm.ResourceOwner = wm.Events[0].Aggregate().ResourceOwner
+	}
+
+	wm.ProcessedSequence = wm.Events[len(wm.Events)-1].Sequence()
+	wm.ChangeDate = wm.Events[len(wm.Events)-1].CreationDate()
+
+	// all events processed and not needed anymore
+	wm.Events = nil
+	wm.Events = []EventReader{}
+	return nil
+}