package main  
      
    import (  
        "fmt"  
        "io"  
        "net/http"  
		"os"  
		//"strconv"  
		"bufio"	
		"strings"
		"os/exec"

		"log"
	)
	
	func MergeVideo(mergeFile, videoName string) int{
		var nRetsult int
		nRetsult=0

		fmt.Printf("Merging video parts into %s\n", videoName)
		cmd := exec.Command("ffmpeg", "-y", "-f", "concat", "-safe", "-1",
			"-i", mergeFile, "-c", "copy", "-bsf:a", "aac_adtstoasc", videoName,
		)
		err := cmd.Run()
		if err != nil {
			log.Fatal(err)
		}

		nRetsult=1
		return nRetsult
	}

	func downloadByM3u8File(strM3u8FilePath string) int{
		var nRetsult int
		nRetsult=0

		var strSlices []string
		var strFilename string

		M3u8file, err := os.Open(strM3u8FilePath)//打开文件   //check m3u8 Is Exist

		//create ffmpeg merge file
		mergeFile := strM3u8FilePath + "-merge.txt"


		file, _ := os.Create(mergeFile) //if exist ,truncate


		defer M3u8file.Close() //打开文件出错处理 
		if nil == err {
			buff := bufio.NewReader(M3u8file) //读入缓存   		
			for {
				//line, isPrefix,err := buff.ReadLine()
				
				httpAddress, err := buff.ReadString(\'\n\') //以\'\n\'为结束符读入一行
				if err != nil || io.EOF == err {
					break
				}

				//if(strings.Contains(httpAddress, ".ts")){
				if(strings.Contains(httpAddress, "http")){
					httpAddress = strings.TrimSpace(httpAddress)
					httpAddress = strings.TrimRight(httpAddress,"\n")

					strSlices = strings.Split(httpAddress,"/")  //分离成多个 slices
					strFilename = strSlices[len(strSlices)-1]    //取最后 的文件名
					
		
					//write ffmpeg merge file
					file.Write([]byte(fmt.Sprintf("file %s\n", strFilename)))

					res, err := http.Get(httpAddress)  //获取失败？
					if err != nil {  
						panic(err)  
					}  
					


					TsFile, err := os.Create(strFilename)  
					if err != nil {  
						panic(err)  
					}  

					fileSize,writeErr := io.Copy(TsFile, res.Body) 
					TsFile.Close()

					fmt.Println(strFilename + " download done,", "file size(byte)=", fileSize)
					if writeErr != nil {  
						fmt.Println(strFilename + " download failed ",  "errorInfo=", writeErr.Error())
						panic(err)  
					}  

					


					//此行有ts文件，应该下载
					nRetsult++
					fmt.Print(httpAddress)  //可以对一行进行处理
				}
				//fmt.Print(line)  //可以对一行进行处理

			}
		}else{
			fmt.Println(strM3u8FilePath , " file do not exist")
		}

		file.Close()

		return nRetsult
	}



	/*
// M3u8URLs get all urls from m3u8 url
func M3u8URLs(uri string) []string {
	html := request.Get(uri)
	lines := strings.Split(html, "\n")
	var urls []string
	for _, line := range lines {
		line = strings.TrimSpace(line)
		if line != "" && !strings.HasPrefix(line, "#") {
			if strings.HasPrefix(line, "http") {
				urls = append(urls, line)
			} else {
				base, _ := url.Parse(uri)
				u, _ := url.Parse(line)
				urls = append(urls, fmt.Sprintf("%s", base.ResolveReference(u)))
			}
		}
	}
	return urls
}
*/
    func main() {


		//要设置launch.json的 argv 才能debug 用参数
		if( len(os.Args)!= 2 ){
			fmt.Println("参数不正确，请确认输入m3u8文件。 格式如： 1.exe a.mau8")  
			return
		}


		/*
		argsWithProg := os.Args
		argsWithoutProg := os.Args[1:] 
		*/

		arg := os.Args[1] //第二个参数  
		fmt.Println(arg) 

		//还需要 判断输入的参数个数，

		fmt.Println("download begin.....") 

		nRet := downloadByM3u8File(arg)
		fmt.Println("已下载共 %d 个ts文件",nRet) 

		//MergeVideo("1.mp4","record.m3u8-merge.txt")

		

		fmt.Println("download finish.") 

	}