package stat

import (
	"bufio"
	"fmt"
	"io"
	"regexp"
	"strings"
	"strconv"
	"git.loafle.net/overflow/ssh_crawler/util"
)

type NetDevStat struct {
	Iface,
	RecvByte,
	RecvPacket,
	RecvErr,
	RecvDrop,
	RecvFifo,
	RecvFrame,
	RecvCompressed,
	RecvMulticast,
	TransByte,
	TransPacket,
	TransErr,
	TransDrop,
	TransFifo,
	TransFrame,
	TransCompressed,
	TransMulticast string
}

func (net *NetDevStat) Command() string {
	return "cat /proc/net/dev"
}

func (net *NetDevStat) Read(r io.Reader, keys []string) (interface{}, error) {
	var (
		scanner            = bufio.NewScanner(r)
		procNetDevFieldSep = regexp.MustCompile("[ :] *")
		stats        = []NetDevStat{}
	)
	scanner.Scan()
	scanner.Scan()
	parts := strings.Split(scanner.Text(), "|")
	if len(parts) != 3 { // interface + receive + transmit
		return nil, fmt.Errorf("invalid header line in net/dev: %s",
			scanner.Text())
	}

	header := strings.Fields(parts[1])
	for scanner.Scan() {
		line := strings.TrimLeft(scanner.Text(), " ")
		parts := procNetDevFieldSep.Split(line, -1)
		if len(parts) != 2*len(header)+1 {
			return nil, fmt.Errorf("invalid line in net/dev: %s", scanner.Text())
		}

		dev := parts[0][:len(parts[0])]
		stats = append(stats, NetDevStat{
			Iface:           dev,
			RecvByte:        parts[1],
			RecvPacket:      parts[2],
			RecvErr:         parts[3],
			RecvDrop:        parts[4],
			RecvFifo:        parts[5],
			RecvFrame:       parts[6],
			RecvCompressed:  parts[7],
			RecvMulticast:   parts[8],
			TransByte:       parts[9],
			TransPacket:     parts[10],
			TransErr:        parts[11],
			TransDrop:       parts[12],
			TransFifo:       parts[13],
			TransFrame:      parts[14],
			TransCompressed: parts[15],
			TransMulticast:  parts[16],
		})
	}

	if keys == nil {
		return &stats, nil
	}

	res, err := net.parse(keys, stats)
	if err != nil {
		return nil, err
	}

	return &res, scanner.Err()
}

func (net *NetDevStat) parse(keys []string, data []NetDevStat) (map[string]string, error) {
	resMap := make(map[string]string)

	for _, key := range keys  {
		t := strings.Split(key, ".")
		suffix := t[len(t)-1]
		ext := util.ExtractInBracket(key)
		idx, _ := strconv.Atoi(ext)

		var regex = regexp.MustCompile(`\[(.*?)\]`)
		rk := regex.ReplaceAllString(key, ``)

		switch suffix {
		case "iface":
			resMap[rk] = data[idx].Iface
		case "recv_byte":
			resMap[rk] = data[idx].RecvByte
		case "recv_packet":
			resMap[rk] = data[idx].RecvPacket
		case "recv_err":
			resMap[rk] = data[idx].RecvErr
		case "recv_drop":
			resMap[rk] = data[idx].RecvDrop
		case "recv_fifo":
			resMap[rk] = data[idx].RecvFifo
		case "recv_frame":
			resMap[rk] = data[idx].RecvFrame
		case "recv_compressed":
			resMap[rk] = data[idx].RecvCompressed
		case "recv_multicast":
			resMap[rk] = data[idx].RecvMulticast

		case "send_byte":
			resMap[rk] = data[idx].TransByte
		case "send_packet":
			resMap[rk] = data[idx].TransPacket
		case "send_err":
			resMap[rk] = data[idx].TransErr
		case "send_drop":
			resMap[rk] = data[idx].TransDrop
		case "send_fifo":
			resMap[rk] = data[idx].TransFifo
		case "send_frame":
			resMap[rk] = data[idx].TransFrame
		case "send_compressed":
			resMap[rk] = data[idx].TransCompressed
		case "send_multicast":
			resMap[rk] = data[idx].TransMulticast
		default:

		}
	}

	return resMap, nil
}