package timer

import (
	"context"
	"errors"
	"time"
)

var ErrTimeout = errors.New("execution timed out")

// RunTimeout 执行带超时控制的任务，并支持打点追踪
func RunTimeout[T any](timeout time.Duration, fn func(tk *Tracker) (T, error)) (T, error) {
	tk := Start()
	ctx, cancel := context.WithTimeout(context.Background(), timeout)
	defer cancel()

	done := make(chan struct {
		res T
		err error
	}, 1)

	go func() {
		res, err := fn(tk)
		done <- struct {
			res T
			err error
		}{res, err}
	}()

	select {
	case <-ctx.Done():
		var zero T
		return zero, ErrTimeout
	case result := <-done:
		return result.res, result.err
	}
}