Check links of groups before delete it (#1010)

* Check links of groups before delete it

* Add delete group handler test

* Rename dns error msg

* Add delete group test

* Remove rule check

The policy cover this scenario

* Fix test

* Check disabled management grps

* Change error message

* Add new activity for group delete event

management/server/group_test.go

@@ -0,0 +1,164 @@
+package server
+
+import (
+	"testing"
+
+	nbdns "github.com/netbirdio/netbird/dns"
+	"github.com/netbirdio/netbird/route"
+)
+
+const (
+	groupAdminUserID = "testingAdminUser"
+)
+
+func TestDefaultAccountManager_DeleteGroup(t *testing.T) {
+	am, err := createManager(t)
+	if err != nil {
+		t.Error("failed to create account manager")
+	}
+
+	account, err := initTestGroupAccount(am)
+	if err != nil {
+		t.Error("failed to init testing account")
+	}
+
+	testCases := []struct {
+		name           string
+		groupID        string
+		expectedReason string
+	}{
+		{
+			"route",
+			"grp-for-route",
+			"route",
+		},
+		{
+			"name server groups",
+			"grp-for-name-server-grp",
+			"name server groups",
+		},
+		{
+			"policy",
+			"grp-for-policies",
+			"policy",
+		},
+		{
+			"setup keys",
+			"grp-for-keys",
+			"setup key",
+		},
+		{
+			"users",
+			"grp-for-users",
+			"user",
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			err = am.DeleteGroup(account.Id, "", testCase.groupID)
+			if err == nil {
+				t.Errorf("delete %s group successfully", testCase.groupID)
+				return
+			}
+
+			gErr, ok := err.(*GroupLinkError)
+			if !ok {
+				t.Error("invalid error type")
+				return
+			}
+			if gErr.Resource != testCase.expectedReason {
+				t.Errorf("invalid error case: %s, expected: %s", gErr.Resource, testCase.expectedReason)
+			}
+		})
+	}
+}
+
+func initTestGroupAccount(am *DefaultAccountManager) (*Account, error) {
+	accountID := "testingAcc"
+	domain := "example.com"
+
+	groupForRoute := &Group{
+		"grp-for-route",
+		"Group for route",
+		GroupIssuedAPI,
+		make([]string, 0),
+	}
+
+	groupForNameServerGroups := &Group{
+		"grp-for-name-server-grp",
+		"Group for name server groups",
+		GroupIssuedAPI,
+		make([]string, 0),
+	}
+
+	groupForPolicies := &Group{
+		"grp-for-policies",
+		"Group for policies",
+		GroupIssuedAPI,
+		make([]string, 0),
+	}
+
+	groupForSetupKeys := &Group{
+		"grp-for-keys",
+		"Group for setup keys",
+		GroupIssuedAPI,
+		make([]string, 0),
+	}
+
+	groupForUsers := &Group{
+		"grp-for-users",
+		"Group for users",
+		GroupIssuedAPI,
+		make([]string, 0),
+	}
+
+	routeResource := &route.Route{
+		ID:     "example route",
+		Groups: []string{groupForRoute.ID},
+	}
+
+	nameServerGroup := &nbdns.NameServerGroup{
+		ID:     "example name server group",
+		Groups: []string{groupForNameServerGroups.ID},
+	}
+
+	policy := &Policy{
+		ID: "example policy",
+		Rules: []*PolicyRule{
+			{
+				ID:           "example policy rule",
+				Destinations: []string{groupForPolicies.ID},
+			},
+		},
+	}
+
+	setupKey := &SetupKey{
+		Id:         "example setup key",
+		AutoGroups: []string{groupForSetupKeys.ID},
+	}
+
+	user := &User{
+		Id:         "example user",
+		AutoGroups: []string{groupForUsers.ID},
+	}
+	account := newAccountWithId(accountID, groupAdminUserID, domain)
+	account.Routes[routeResource.ID] = routeResource
+	account.NameServerGroups[nameServerGroup.ID] = nameServerGroup
+	account.Policies = append(account.Policies, policy)
+	account.SetupKeys[setupKey.Id] = setupKey
+	account.Users[user.Id] = user
+
+	err := am.Store.SaveAccount(account)
+	if err != nil {
+		return nil, err
+	}
+
+	_ = am.SaveGroup(accountID, groupAdminUserID, groupForRoute)
+	_ = am.SaveGroup(accountID, groupAdminUserID, groupForNameServerGroups)
+	_ = am.SaveGroup(accountID, groupAdminUserID, groupForPolicies)
+	_ = am.SaveGroup(accountID, groupAdminUserID, groupForSetupKeys)
+	_ = am.SaveGroup(accountID, groupAdminUserID, groupForUsers)
+
+	return am.Store.GetAccount(account.Id)
+}