feat(login): use new IDP templates (#5315)

The login uses the new template based IDPs with backwards compatibility for old IDPs

internal/command/idp.go

@@ -1,6 +1,12 @@
 package command
 
-import "github.com/zitadel/zitadel/internal/repository/idp"
+import (
+	"context"
+
+	"github.com/zitadel/zitadel/internal/api/authz"
+	"github.com/zitadel/zitadel/internal/command/preparation"
+	"github.com/zitadel/zitadel/internal/repository/idp"
+)
 
 type GenericOAuthProvider struct {
 	Name                  string
@@ -52,3 +58,34 @@ type LDAPProvider struct {
 	LDAPAttributes      idp.LDAPAttributes
 	IDPOptions          idp.Options
 }
+
+func ExistsIDP(ctx context.Context, filter preparation.FilterToQueryReducer, id, orgID string) (exists bool, err error) {
+	writeModel := NewOrgIDPRemoveWriteModel(orgID, id)
+	events, err := filter(ctx, writeModel.Query())
+	if err != nil {
+		return false, err
+	}
+
+	if len(events) > 0 {
+		writeModel.AppendEvents(events...)
+		if err := writeModel.Reduce(); err != nil {
+			return false, err
+		}
+		return writeModel.State.Exists(), nil
+	}
+
+	instanceWriteModel := NewInstanceIDPRemoveWriteModel(authz.GetInstance(ctx).InstanceID(), id)
+	events, err = filter(ctx, instanceWriteModel.Query())
+	if err != nil {
+		return false, err
+	}
+
+	if len(events) == 0 {
+		return false, nil
+	}
+	instanceWriteModel.AppendEvents(events...)
+	if err := instanceWriteModel.Reduce(); err != nil {
+		return false, err
+	}
+	return instanceWriteModel.State.Exists(), nil
+}