refactor(portainer): introduce internal package (#3924)

* refactor(auth): move auth helpers to internal package

* refactor(edge-compute): move edge helpers to internal package

* refactor(tags): move tags helper to internal package

* style(portainer): sort imports

api/internal/edge/edgestack.go

@@ -0,0 +1,30 @@
+package edge
+
+import (
+	"errors"
+	"github.com/portainer/portainer/api"
+)
+
+// EdgeStackRelatedEndpoints returns a list of endpoints related to this Edge stack
+func EdgeStackRelatedEndpoints(edgeGroupIDs []portainer.EdgeGroupID, endpoints []portainer.Endpoint, endpointGroups []portainer.EndpointGroup, edgeGroups []portainer.EdgeGroup) ([]portainer.EndpointID, error) {
+	edgeStackEndpoints := []portainer.EndpointID{}
+
+	for _, edgeGroupID := range edgeGroupIDs {
+		var edgeGroup *portainer.EdgeGroup
+
+		for _, group := range edgeGroups {
+			if group.ID == edgeGroupID {
+				edgeGroup = &group
+				break
+			}
+		}
+
+		if edgeGroup == nil {
+			return nil, errors.New("Edge group was not found")
+		}
+
+		edgeStackEndpoints = append(edgeStackEndpoints, EdgeGroupRelatedEndpoints(edgeGroup, endpoints, endpointGroups)...)
+	}
+
+	return edgeStackEndpoints, nil
+}