package iperf

import (
	"fmt"
	"github.com/BGrewell/tail"
	"github.com/BGrewell/go-conversions"
	"log"
	"strconv"
	"strings"
)

type Reporter struct {
	ReportingChannel chan *StreamIntervalReport
	LogFile string
	running bool
}

func (r *Reporter) Start() {
	r.running = true
	go r.runLogProcessor()
}

func (r *Reporter) Stop() {
	r.running = false
	close(r.ReportingChannel)
}

func (r *Reporter) runLogProcessor() {
	tailer, err := tail.TailFile(r.LogFile, tail.Config{
		Follow: true,
		ReOpen: true,
		Poll: true,
		MustExist: true,
	})
	if err != nil {
		log.Fatalf("failed to tail log file: %v", err)
	}
	for line := range tailer.Lines {
		// TODO: For now this only cares about individual streams it ignores the sum lines
		if len(line.Text) > 5 {
			id := line.Text[1:4]
			stream, err := strconv.Atoi(strings.TrimSpace(id))
			if err != nil {
				continue
			}
			fields := strings.Fields(line.Text[5:])
			if len(fields) >= 6 {
				if fields[0] == "local" {
					continue
				}
				timeFields := strings.Split(fields[0], "-")
				start, err := strconv.ParseFloat(timeFields[0], 32)
				if err != nil {
					log.Printf("failed to convert start time: %s\n", err)
				}
				end, err := strconv.ParseFloat(timeFields[1], 32)
				transferedStr := fmt.Sprintf("%s%s", fields[2], fields[3])
				transferedBytes, err := conversions.StringBitRateToInt(transferedStr)
				if err != nil {
					log.Printf("failed to convert units: %s\n", err)
				}
				transferedBytes = transferedBytes / 8
				rateStr := fmt.Sprintf("%s%s", fields[4], fields[5])
				rate, err := conversions.StringBitRateToInt(rateStr)
				if err != nil {
					log.Printf("failed to convert units: %s\n", err)
				}
				omitted := false
				if len(fields) >= 7 && fields[6] == "(omitted)" {
					omitted = true
				}
				report := &StreamIntervalReport{
					Socket:        stream,
					StartInterval: float32(start),
					EndInterval:   float32(end),
					Seconds:       float32(end - start),
					Bytes:         int(transferedBytes),
					BitsPerSecond: float64(rate),
					Omitted:       omitted,
				}
				r.ReportingChannel <- report
			}
		}

		if !r.running {
			return
		}
	}
}