package stat

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

type DiskIOStat struct {
	Device,
	ReadCompleted,
	ReadMerged,
	SectorRead,
	TimeSpentReading,
	WritesCompleted,
	WritesMerged,
	SectorsWritten,
	TimeSpentWriting,
	IoInProg,
	TimeSpentIO,
	WeightedTimeSpentIO string
}

func (diskio DiskIOStat) Command() string {
	return "cat /proc/diskstats"
}

func (diskio DiskIOStat) Read(r io.Reader, keys []string) (interface{}, error) {
	var (
		stats   = []DiskIOStat{}
		scanner = bufio.NewScanner(r)
	)

	for scanner.Scan() {
		parts := strings.Fields(scanner.Text())
		if len(parts) < 4 {
			return nil, fmt.Errorf("invalid line in %s: %s", "/proc/diskstats", scanner.Text())
		}
		deviceName := parts[2]
		if !strings.HasPrefix(deviceName, "sd") {
			continue
		}
		stats = append(stats, DiskIOStat{
			Device:              deviceName,
			ReadCompleted:       parts[3],
			ReadMerged:          parts[4],
			SectorRead:          parts[5],
			TimeSpentReading:    parts[6],
			WritesCompleted:     parts[7],
			WritesMerged:        parts[8],
			SectorsWritten:      parts[9],
			TimeSpentWriting:    parts[10],
			IoInProg:            parts[11],
			TimeSpentIO:         parts[12],
			WeightedTimeSpentIO: parts[13],
		})
	}

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

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


	return &res, scanner.Err()
}

func (diskio DiskIOStat) parse(keys []string, data []DiskIOStat) (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)
		switch suffix {
		case "device":
			resMap[key] = data[idx].Device
		case "readcnt":
			resMap[key] = data[idx].ReadCompleted
		case "merged_readcnt":
			resMap[key] = data[idx].ReadMerged
		case "readbytes":
			resMap[key] = util.Float64ToString(util.StringToFloat64(data[idx].SectorRead) * 512)
		case "readtime":
			resMap[key] = data[idx].TimeSpentReading
		case "writecnt":
			resMap[key] = data[idx].WritesCompleted
		case "merged_writecnt":
			resMap[key] = data[idx].WritesMerged
		case "writebytes":
			resMap[key] = util.Float64ToString(util.StringToFloat64(data[idx].SectorsWritten) * 512)
		case "writetime":
			resMap[key] = data[idx].TimeSpentWriting
		case "iotime":
			resMap[key] = data[idx].TimeSpentIO
		case "ioweighted":
			resMap[key] = data[idx].WeightedTimeSpentIO
		default:

		}
	}

	return resMap, nil
}