// +build !windows

package staros

import (
	"errors"
	"io/ioutil"
	"strconv"
	"strings"
	"time"
)

func NetUsage() ([]NetAdapter, error) {
	data, err := ioutil.ReadFile("/proc/net/dev")
	if err != nil {
		return []NetAdapter{}, err
	}
	sps := strings.Split(strings.TrimSpace(string(data)), "\n")
	if len(sps) < 3 {
		return []NetAdapter{}, errors.New("No Adaptor")
	}
	var res []NetAdapter
	netLists := sps[2:]
	for _, v := range netLists {
		v = strings.ReplaceAll(v, "   ", "  ")
		for strings.Contains(v, "  ") {
			v = strings.ReplaceAll(v, "  ", " ")
		}
		v = strings.TrimSpace(v)
		card := strings.Split(v, " ")
		name := strings.ReplaceAll(card[0], ":", "")
		recvBytes, _ := strconv.Atoi(card[1])
		sendBytes, _ := strconv.Atoi(card[9])
		res = append(res, NetAdapter{name, uint64(recvBytes), uint64(sendBytes)})
	}
	return res, nil
}

func NetUsageByname(name string) (NetAdapter, error) {
	ada, err := NetUsage()
	if err != nil {
		return NetAdapter{}, err
	}
	for _, v := range ada {
		if v.Name == name {
			return v, nil
		}
	}
	return NetAdapter{}, errors.New("Not Found")
}

func NetSpeeds(duration time.Duration) ([]NetSpeed, error) {
	list1, err := NetUsage()
	if err != nil {
		return []NetSpeed{}, err
	}
	time.Sleep(duration)
	list2, err := NetUsage()
	if err != nil {
		return []NetSpeed{}, err
	}
	if len(list1) > len(list2) {
		return []NetSpeed{}, errors.New("NetWork Adaptor Num Not ok")
	}
	var res []NetSpeed
	for k, v := range list1 {
		recv := float64(list2[k].RecvBytes-v.RecvBytes) / duration.Seconds()
		send := float64(list2[k].SendBytes-v.SendBytes) / duration.Seconds()
		res = append(res, NetSpeed{v.Name, recv, send})
	}
	return res, nil
}

func NetSpeedsByName(duration time.Duration, name string) (NetSpeed, error) {
	ada, err := NetSpeeds(duration)
	if err != nil {
		return NetSpeed{}, err
	}
	for _, v := range ada {
		if v.Name == name {
			return v, nil
		}
	}
	return NetSpeed{}, errors.New("Not Found")
}