package middleware

import (
	"net/http"
	"time"
)

// Timeout caps each request's handler time at the application level, on top
// of http.Server's network-level ReadTimeout/WriteTimeout. It wraps net/http's
// TimeoutHandler: the handler runs with a deadline-carrying context, and once
// the deadline passes the client gets a 503 while any late writes from the
// handler goroutine are rejected with http.ErrHandlerTimeout. The previous
// hand-rolled version wrote the timeout response concurrently with the
// still-running handler goroutine — a concurrent map write on the header map
// that crashed the whole process ("fatal error: concurrent map read and map
// write") whenever a request outlived the deadline mid-write.
func Timeout(duration time.Duration) Middleware {
	return func(next http.Handler) http.Handler {
		return http.TimeoutHandler(next, duration, "Request timed out")
	}
}