From b9e7c186c8ab865ed55c473fca6f4f660198bb1d Mon Sep 17 00:00:00 2001
From: Kutluhan Metin <kutluhan.metin@hazelcast.com>
Date: Fri, 3 Nov 2023 18:21:50 +0300
Subject: [PATCH] [CLC-425]: Print Warnings Before Exit (#420)

---
 base/commands/migration/migration_stages.go | 23 +++++++++++++++++++++
 base/commands/migration/migration_start.go  |  1 +
 base/commands/migration/migration_status.go |  1 +
 3 files changed, 25 insertions(+)

diff --git a/base/commands/migration/migration_stages.go b/base/commands/migration/migration_stages.go
index 6cb16763..b2fbc090 100644
--- a/base/commands/migration/migration_stages.go
+++ b/base/commands/migration/migration_stages.go
@@ -271,6 +271,26 @@ func finalizeMigration(ctx context.Context, ec plug.ExecContext, ci *hazelcast.C
 	return nil
 }
 
+func maybePrintWarnings(ctx context.Context, ec plug.ExecContext, ci *hazelcast.ClientInternal, migrationID string) {
+	q := fmt.Sprintf(`SELECT JSON_QUERY(this, '$.warnings' WITH WRAPPER) FROM %s WHERE __key='%s'`, StatusMapName, migrationID)
+	row, err := querySingleRow(ctx, ci, q)
+	if err != nil {
+		ec.Logger().Error(err)
+		return
+	}
+	var warnings []string
+	err = json.Unmarshal(row.(serialization.JSON), &warnings)
+	if err != nil {
+		ec.Logger().Error(err)
+		return
+	}
+	if len(warnings) <= 5 {
+		ec.PrintlnUnnecessary("* " + strings.Join(warnings, "\n* "))
+	} else {
+		ec.PrintlnUnnecessary(fmt.Sprintf("You have %d warnings that you can find in your migration report.", len(warnings)))
+	}
+}
+
 func querySingleRow(ctx context.Context, ci *hazelcast.ClientInternal, query string) (any, error) {
 	res, err := ci.Client().SQL().Execute(ctx, query)
 	if err != nil {
@@ -290,6 +310,9 @@ func querySingleRow(ctx context.Context, ci *hazelcast.ClientInternal, query str
 		if err != nil {
 			return "", err
 		}
+		if r == nil {
+			return nil, errors.New("no rows found")
+		}
 		return r, nil
 	}
 	return nil, errors.New("no rows found")
diff --git a/base/commands/migration/migration_start.go b/base/commands/migration/migration_start.go
index 84368199..fdb7cfe5 100644
--- a/base/commands/migration/migration_start.go
+++ b/base/commands/migration/migration_start.go
@@ -54,6 +54,7 @@ Selected data structures in the source cluster will be migrated to the target cl
 	ec.PrintlnUnnecessary("")
 	mID := MakeMigrationID()
 	defer func() {
+		maybePrintWarnings(ctx, ec, ci, mID)
 		finalizeErr := finalizeMigration(ctx, ec, ci, mID, ec.Props().GetString(flagOutputDir))
 		if err == nil {
 			err = finalizeErr
diff --git a/base/commands/migration/migration_status.go b/base/commands/migration/migration_status.go
index aeba1993..40cf9e71 100644
--- a/base/commands/migration/migration_status.go
+++ b/base/commands/migration/migration_status.go
@@ -37,6 +37,7 @@ func (s StatusCmd) Exec(ctx context.Context, ec plug.ExecContext) (err error) {
 		return err
 	}
 	defer func() {
+		maybePrintWarnings(ctx, ec, ci, mID.(string))
 		finalizeErr := finalizeMigration(ctx, ec, ci, mID.(string), ec.Props().GetString(flagOutputDir))
 		if err == nil {
 			err = finalizeErr