package util

import (
	"time"

	v1 "github.com/open-policy-agent/opa/v1/util"
)

// TimerWithCancel exists because of memory leaks when using
// time.After in select statements. Instead, we now manually create timers,
// wait on them, and manually free them.
//
// See this for more details:
// https://www.arangodb.com/2020/09/a-story-of-a-memory-leak-in-go-how-to-properly-use-time-after/
//
// Note: This issue is fixed in Go 1.23, but this fix helps us until then.
//
// Warning: the cancel cannot be done concurrent to reading, everything should
// work in the same goroutine.
//
// Example:
//
//	for retries := 0; true; retries++ {
//
//		...main logic...
//
//		timer, cancel := utils.TimerWithCancel(utils.Backoff(retries))
//		select {
//		case <-ctx.Done():
//			cancel()
//			return ctx.Err()
//		case <-timer.C:
//			continue
//		}
//	}
func TimerWithCancel(delay time.Duration) (*time.Timer, func()) {
	return v1.TimerWithCancel(delay)
}