//
//  Copyright 2026 The InfiniFlow Authors. All Rights Reserved.
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.
//

package utility

// TruncateRunes returns s truncated to at most max runes, preserving the
// original bytes when shorter. Truncation counts runes (not bytes), so
// multi-byte characters are never split. A non-positive max yields the empty
// string.
//
// This is the single shared implementation previously duplicated in
// internal/ingestion/task/debug_log_sink.go and internal/service/agent_sessions.go.
func TruncateRunes(s string, max int) string {
	if max <= 0 {
		return ""
	}
	r := []rune(s)
	if len(r) <= max {
		return s
	}
	return string(r[:max])
}