package p2p

import (
	"golang.org/x/sync/errgroup"
	"io/ioutil"
	"net/http"
	"net/url"
	"strconv"
	"strings"
	"time"
)

var dlSizes = [...]int{350, 500, 750, 1000, 1500, 2000, 2500, 3000, 3500, 4000}
var ulSizes = [...]int{100, 300, 500, 800, 1000, 1500, 2500, 3000, 3500, 4000} //kB
var client = http.Client{}

// DownloadTest executes the test to measure download speed
func (s *IpAddress) DownloadTest(savingMode bool) error {
	dlURL := "http://" + s.Ipv4 + ":8088/server_info"
	eg := errgroup.Group{}

	// Warming up
	sTime := time.Now()
	for i := 0; i < 2; i++ {
		eg.Go(func() error {
			return dlWarmUp("http://" + s.Ipv4 + ":8088/server_info")
		})
	}
	if err := eg.Wait(); err != nil {
		return err
	}
	fTime := time.Now()
	// 1.125MB for each request (750 * 750 * 2)
	wuSpeed := 1.125 * 8 * 2 / fTime.Sub(sTime.Add(s.Latency)).Seconds()

	// Decide workload by warm up speed
	workload := 0
	weight := 0
	skip := false
	if savingMode {
		workload = 6
		weight = 3
	} else if 10.0 < wuSpeed {
		workload = 16
		weight = 4
	} else if 4.0 < wuSpeed {
		workload = 8
		weight = 4
	} else if 2.5 < wuSpeed {
		workload = 4
		weight = 4
	} else {
		skip = true
	}

	// Main speedtest
	dlSpeed := wuSpeed
	if skip == false {
		sTime = time.Now()
		for i := 0; i < workload; i++ {
			eg.Go(func() error {
				return downloadRequest(dlURL, weight)
			})
		}
		if err := eg.Wait(); err != nil {
			return err
		}
		fTime = time.Now()

		reqMB := dlSizes[weight] * dlSizes[weight] * 2 / 1000 / 1000
		dlSpeed = float64(reqMB) * 8 * float64(workload) / fTime.Sub(sTime).Seconds()
	}

	s.Download = dlSpeed
	return nil
}

// Download Speed
func (s *IpAddress)DownloadSpeed() error {
	start := time.Now()
	resp, err := client.Get("http://" + s.Ipv4 + ":8080/50")
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	ioutil.ReadAll(resp.Body)
	t := time.Since(start)
	//fmt.Println(s.Seconds())
	// size * time (seconds)
	s.Download = (50/t.Seconds())*8
    return nil
}

// UploadTest executes the test to measure upload speed
func (s *IpAddress) UploadTest(savingMode bool) error {
	// Warm up
	sTime := time.Now()
	eg := errgroup.Group{}
	for i := 0; i < 2; i++ {
		eg.Go(func() error {
			return ulWarmUp("http://" + s.Ipv4 + ":8088/server_info")
		})
	}
	if err := eg.Wait(); err != nil {
		return err
	}
	fTime := time.Since(sTime)
	// 1.0 MB for each request
	wuSpeed := 1.0 * 8 * 2 / (fTime.Seconds() + s.Latency.Seconds())

	// Decide workload by warm up speed
	workload := 0
	weight := 0
	skip := false
	if savingMode {
		workload = 1
		weight = 7
	} else if 10.0 < wuSpeed {
		workload = 16
		weight = 9
	} else if 4.0 < wuSpeed {
		workload = 8
		weight = 9
	} else if 2.5 < wuSpeed {
		workload = 4
		weight = 5
	} else {
		skip = true
	}

	// Main speedtest
	ulSpeed := wuSpeed
	if skip == false {
		sTime = time.Now()
		for i := 0; i < workload; i++ {
			eg.Go(func() error {
				return uploadRequest("http://"+s.Ipv4+":8088/server_info")
			})
		}
		if err := eg.Wait(); err != nil {
			return err
		}
		fTime := time.Since(sTime)

		reqMB := float64(ulSizes[weight]) / 1000
		ulSpeed = reqMB * 8 * float64(workload) / fTime.Seconds()
	}

	s.Upload = ulSpeed

	return nil
}

func dlWarmUp(dlURL string) error {
	size := dlSizes[2]
	xdlURL := dlURL + "/random" + strconv.Itoa(size) + "x" + strconv.Itoa(size) + ".jpg"

	resp, err := client.Get(xdlURL)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	ioutil.ReadAll(resp.Body)

	return nil
}

func ulWarmUp(ulURL string) error {
	size := ulSizes[4]
	v := url.Values{}
	v.Add("content", strings.Repeat("0123456789", size*100-51))

	resp, err := client.PostForm(ulURL, v)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	ioutil.ReadAll(resp.Body)

	return nil
}

func downloadRequest(dlURL string, w int) error {
	size := dlSizes[w]
	xdlURL := dlURL + "/random" + strconv.Itoa(size) + "x" + strconv.Itoa(size) + ".jpg"

	resp, err := client.Get(xdlURL)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	ioutil.ReadAll(resp.Body)

	return nil
}

func uploadRequest(ulURL string) error {
	size := ulSizes[9]
	v := url.Values{}
	v.Add("content", strings.Repeat("0123456789", size*100-51))

	resp, err := client.PostForm(ulURL, v)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	ioutil.ReadAll(resp.Body)

	return nil
}

// PingTest executes test to measure latency
func (s *IpAddress) PingTest() error {
	//pingURL := strings.Split(s.URL, "/upload")[0] + "/latency.txt"
	  pingURL := "http://" + s.Ipv4 + ":8088/server_info"
	l := time.Duration(100000000000) // 10sec
	for i := 0; i < 3; i++ {
		sTime := time.Now()
		resp, err := http.Get(pingURL)
		fTime := time.Now()
		if err != nil {
			return err
		}
		if fTime.Sub(sTime) < l {
			l = fTime.Sub(sTime)
		}
		resp.Body.Close()
	}

	s.Latency = time.Duration(int64(l.Nanoseconds() / 2))

	return nil
}