package main

import (
  "fmt"
  "github.com/jnovack/flag"
  log "github.com/sirupsen/logrus"
//  "strings"
//  "strconv"
  "time"
  "os"
  "bytes"
  "net/http"
  "io/ioutil"
  "encoding/json"
  "bufio"
//  "bufio"
//  "runtime"
//  "sync"
//  "github.com/mmcloughlin/geohash"
//  "github.com/tzneal/ham-go/dxcc"
//  "github.com/denzs/wsjtx-dashboards/shared/httpstuff"
  "github.com/hpcloud/tail"
)

var alltxt      string
var station     string
var identifier    string
var password    string
var uri         string
var minlen      int
var readall     bool

func usage() {
    fmt.Printf("Usage of %s:\n", os.Args[0])
    flag.PrintDefaults()
}

func init() {
  flag.StringVar(&alltxt, "in", "", "path to wsjt-x ALL.TXT")
  flag.StringVar(&station, "station", "YOURCALL", "your station/username")
  flag.StringVar(&identifier, "identifier", "unset", "your identifier like location of rigname")
  flag.StringVar(&password, "password", "", "your password")
  flag.StringVar(&uri, "uri", "http://http-exporter", "uri to your http-exporter")
  flag.IntVar(&minlen, "minlen", 16, "minimal length for line to be pushed")
  flag.BoolVar(&readall, "readall", false, "submit whole file if nothing found at server")
  flag.Parse()

  if alltxt == "" || station == "" || identifier == "" || uri == "" {
    usage()
    // on windows could do some fancy dialog magic to ask for parameters and service installation ;)
    os.Exit(1)
  }

  formatter := &log.TextFormatter{
    FullTimestamp: true,
  }
  log.SetFormatter(formatter)
}

func getTimestampFromDb() (int64, bool) {
  log.Info("doing timestamp stuff..")
	var ts LastTs

  client := http.Client{
		Timeout: time.Second * 2, // Timeout after 2 seconds
	}

	req, err := http.NewRequest(http.MethodGet, uri + "/timestamp/getLast?identifier=" + identifier, nil)
  log.Info("done req..")

	if err != nil {
		log.Fatal(err)
	}

	req.Header.Set("X-STATION", station)
	req.Header.Set("X-IDENTIFIER", identifier)

  log.Info("done Headet.Set")

	res, getErr := client.Do(req)
  log.Info("done client.Do")
	if getErr != nil {
		log.Fatal(getErr)
	}

  if res.StatusCode != http.StatusOK {
      if res.StatusCode == 404 {
        // FIXME on windows show message to upload all.txt
        log.Info("Yeah, this seems to be our first contact with the server, as it doesnt have any records for %s:%s", station, identifier)
        return 0, false
      }
      fmt.Println("Non-OK HTTP status:", res.StatusCode)
      log.Panic("uh well, there seems to be some serious shit going on...")
  }

	if res.Body != nil {
		defer res.Body.Close()
	}

	body, readErr := ioutil.ReadAll(res.Body)
	if readErr != nil {
		log.Fatal(readErr)
	}

  log.Info("doing json stuff")
	jsonErr := json.Unmarshal(body, &ts)
  log.Info("done json stuff")
	if jsonErr != nil {
		log.Fatal(jsonErr)
	}

  log.Info("doing timestamp stuff done")

  return ts.Last, true
}

// https://forum.golangbridge.org/t/how-to-find-the-offset-of-a-byte-in-a-large-binary-file/16457/2 ;)
// ScanFile returns the offset of the first occurence of a []byte in a file,
// or -1 if []byte was not found in file, and seeks to the beginning of the searched []byte
func findPosition(search []byte) (int64, bool) {
  f, err := os.Open(alltxt)
	if err != nil {
		log.Fatal(err)
	}

	ix := 0
	r := bufio.NewReader(f)
	offset := int64(0)
	for ix < len(search) {
		b, err := r.ReadByte()
		if err != nil {
			return 0, false
		}
		if search[ix] == b {
			ix++
		} else {
			ix = 0
		}
		offset++
	}
//	f.Seek(offset - int64(len(search)), 0 ) // Seeks to the beginning of the searched []byte
  
  //r.Close()
  //readseek.Close()
  f.Close()
	return offset - int64(len(search)), true
}

func unix2wsjtx(ts int64) (string) {
  t := time.Unix(ts, 0)
  s := t.UTC().Format("060102_150405")
  return s
}

func postLine(batchmode bool, lines chan string) {
  // FIXME implement batchmode

//  var l httpstuff.Lines

  for {
    select {
      case line := <- lines :
        l := Lines{}
        l.Text = append(l.Text, line)
        log.Infof("line: %s", l.Text)

    //var jsonStr = []byte(`{"title":"Buy cheese and bread for breakfast."}`)
    jsonStr, err := json.Marshal(l)
    if err != nil {
      log.Errorf("cant marshal json: ", err.Error())
    }
    req, err := http.NewRequest("POST", uri + "/lines/insert", bytes.NewBuffer(jsonStr))
    if err != nil {
        log.Errorf("crazy shit during newrequest", err.Error())
    }
	  req.Header.Set("X-STATION", station)
	  req.Header.Set("X-IDENTIFIER", identifier)
    req.Header.Set("Content-Type", "application/json")

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        log.Errorf("crazy shit during client", err.Error())
    }
    defer resp.Body.Close()

    log.Trace("response Status: ", resp.Status)
    log.Trace("response Headers: ", resp.Header)
    body, _ := ioutil.ReadAll(resp.Body)
    log.Trace("response Body: ", string(body))
    }
  }
  log.Trace("goodbye from postLine")
}

func readFile(offset int64, whence int, done chan bool) {
  log.Trace("start readFile %s", alltxt)

  lines := make(chan string ,2)

  go postLine((whence == 0), lines)
  go postLine((whence == 0), lines)

  t, _:= tail.TailFile(alltxt, tail.Config{Follow: true, Location: &tail.SeekInfo{Offset: offset, Whence: whence},})
  for line := range t.Lines {
    // FIXME
    // at least minlen
    // check for logline format!
    lines <- line.Text
  }

  close(lines)
  log.Trace("readfile is finished")
  done <- true
}

func main(){
  var lastDbTime  int64
  var foundts     bool
  var offset      int64
  var whence      int
  var foundoffset bool

  log.Info("starting up..")

  offset = 0

  if !readall {
    whence = 2
    lastDbTime, foundts = getTimestampFromDb()
    if foundts {
      log.Infof("last timestamp in db: %d", lastDbTime)
      wt := unix2wsjtx(lastDbTime)
      log.Infof("searching %s for: %s",alltxt, wt)
      offset, foundoffset = findPosition([]byte(wt))
      if foundoffset {
        log.Trace("found %s at offset %d ", wt, offset)
        whence = 0
      } else {
        log.Warnf("timestamp %s NOT found in %s! have you deleted your ALL.TXT or used an old identifier?", wt, alltxt)
      log.Warn("sending spots from now on.. consider sending your %s to the database administrator for import", alltxt)
      }
    } else {
      log.Warn("api has no data for %s:%s", station, identifier)
      log.Warn("sending spots from now on.. consider sending your %s to the database administrator for import", alltxt)
    }
  } else {
    log.Info("readall mode enabled..")
    whence = 0
  }

  log.Infof("offset: %d whence: %d", offset, whence)

  done := make(chan bool)
  go readFile(offset, whence, done)
  <- done

  log.Info("..done")
}