package check

import (
	"net/http"
	"net/http/httptrace"
	"time"
)

//HTTPPing returns the response time to fetch a page.
func HTTPPing(target string) (time.Duration, Result, error) {
	var totalTime time.Duration
	var err error
	successCount := 0
	okCount := 0
	for i := 0; i < TryCount; i++ {
		duration, successful, getErr := timeGet(target)
		totalTime += duration
		if getErr != nil {
			err = getErr
		}
		if successful {
			okCount++
		}
		successCount++
	}
	return divide(totalTime, successCount), statusFromSuccessCount(okCount), err
}

func timeGet(url string) (time.Duration, bool, error) {
	req, _ := http.NewRequest("GET", url, nil)

	var connect time.Time
	var duration time.Duration

	trace := &httptrace.ClientTrace{
		ConnectStart: func(network, addr string) { connect = time.Now() },
		GotFirstResponseByte: func() {
			duration = time.Since(connect)
		},
	}

	req = req.WithContext(httptrace.WithClientTrace(req.Context(), trace))
	res, err := http.DefaultTransport.RoundTrip(req)
	if err != nil {
		return 0, false, err
	}
	return duration, res.StatusCode < 400, nil
}