package main

import (
	"bufio"
	"bytes"
	"fmt"
	"github.com/schollz/progressbar/v3"
	"io/fs"
	"io/ioutil"
	"log"
	"os"
	"os/exec"
	"path"
	"regexp"
	"strings"
	"time"
)

//var sourceDir = "/home/lukas/Downloads"

var sourceDir = "V:\\TV_aufnahmen\\Konvertieren"

func main() {
	_files, err := ioutil.ReadDir(sourceDir)
	if err != nil {
		log.Fatal(err)
	}

	var files []string
	for _, file := range _files {
		if validFile(file) {
			files = append(files, path.Join(sourceDir, file.Name()))
		}
	}

	fmt.Printf("Found %d files\n", len(files))
	for _, file := range files {
		fmt.Printf("Converting %s\n", file)
		convert(file)
	}
}

func validFile(file fs.FileInfo) bool {
	return !file.IsDir() && strings.HasSuffix(file.Name(), ".ts")
}

func convert(file string) {
	ext := path.Ext(file)
	outfile := file[0:len(file)-len(ext)] + ".mp4"

	tottime := getVidTime(file)

	com := exec.Command("ffmpeg",
		"-y",                 // overwrite existing out files
		"-hwaccel", "vulkan", // vulkan hardware accelleration
		"-hide_banner", "-loglevel", "warning", // set it less silent
		"-progress", "pipe:1", // pipe a progress text to 1
		"-i", file, // input file
		"-c:v", "h264_amf", // reencode video with amf
		"-c:a", "copy", // copy audio stream
		outfile) // output file
	fmt.Println(com.String())

	// pipe stderr directly to out
	com.Stderr = os.Stderr

	stderr, _ := com.StdoutPipe()
	err := com.Start()

	scanner := bufio.NewScanner(stderr)
	scanner.Split(bufio.ScanLines)

	var infoblock string = ""
	bar := progressbar.Default(tottime)

	for scanner.Scan() {
		m := scanner.Text()
		// we know a new data block begins here
		if strings.Contains(m, "frame=") {
			//fmt.Println(infoblock)
			r := regexp.MustCompile("out_time=(.*)")
			matches := r.FindStringSubmatch(infoblock)
			if len(matches) < 2 {
				continue
			}
			parsedtime, err := time.Parse("15:04:05.000000", matches[1])
			if err != nil {
				fmt.Println("error invalid time")
				continue
			}

			secondtime := 3600*parsedtime.Hour() + parsedtime.Minute()*60 + parsedtime.Second()
			_ = bar.Set(secondtime)

			infoblock = ""
		} else {
			infoblock += m + "\n"
		}
	}
	err = com.Wait()
	_ = bar.Finish()

	if err != nil {
		//fmt.Println(out.String())
		log.Fatal(err)
	}
}

func getVidTime(file string) int64 {
	com := exec.Command("ffmpeg", "-i", file)
	var out bytes.Buffer
	com.Stdout = &out
	com.Stderr = &out

	err := com.Run()

	fmt.Println("output:")
	//fmt.Println(out.String())

	r := regexp.MustCompile("Duration: (.*), start: ")
	matches := r.FindStringSubmatch(out.String())
	if len(matches) < 2 {
		return -1
	}
	fmt.Println(r.FindStringSubmatch(out.String())[1])

	parsedtime, err := time.Parse("15:04:05.00", matches[1])
	if err != nil {
		fmt.Println("error invalid time")
		return 0
	}
	sectime := parsedtime.Hour()*3600 + parsedtime.Minute()*60 + parsedtime.Second()
	fmt.Printf("Length: %d\n", sectime)
	return int64(sectime)
}