package m3u8

import (
	//"sz-app-server/pub/common/utils"

	"crypto/md5"
	"encoding/hex"
	"fmt"
	"stat/common/utils"
	"strings"
	"time"

	"github.com/grafov/m3u8"
)

// makeMediaPlayList 根据from，重新生成播放列表
func makeMediaPlayList(from *m3u8.MediaPlaylist, cdnDomain string, dirPath string, keyUri string, authKey string) (media *m3u8.MediaPlaylist, err error) {
	media, err = m3u8.NewMediaPlaylist(from.WinSize(), from.Count())
	if err != nil {
		return
	}
	base := utils.JoinUrlPath(cdnDomain, dirPath)
	now := time.Now()
	for _, segment := range from.Segments {
		if segment == nil {
			continue
		}
		sg := new(m3u8.MediaSegment)
		sg.URI = utils.JoinUrlPath(base, segment.URI)
		if len(authKey) > 0 {
			//生成鉴权url
			urlPath := utils.JoinUrlPath(dirPath, segment.URI)
			urlAuth := generateUrlAuth(now, urlPath, authKey)
			sg.URI = sg.URI + urlAuth
		}
		sg.Title = segment.Title
		sg.Duration = segment.Duration
		if err = media.AppendSegment(sg); err != nil {
			return
		}
	}
	_ = media.SetDefaultKey("AES-128", keyUri, "", "", "")
	media.Close()
	return
}

// 生成鉴权url
func generateUrlAuth(now time.Time, path string, authKey string) string {
	timestamp := now.Unix()
	// randId := maths.GenUUID()
	signStr := fmt.Sprintf("%s-%d-0-0-%s", path, timestamp, authKey)
	md5Str := getMD5Sign(signStr)
	urlAuth := fmt.Sprintf("?md=%d-0-0-%s", timestamp, md5Str)
	return urlAuth
}

// getMD5Sign 得到签名
func getMD5Sign(buf string) string {
	md5Ctx := md5.New()
	md5Ctx.Write([]byte(buf))
	cipherStr := md5Ctx.Sum(nil)
	nsign := hex.EncodeToString(cipherStr)
	return nsign
}

func newMediaPlayList(from *m3u8.MediaPlaylist, cdnDomain, origDomain, dirPath, keyUri string, needHeader bool) (media *m3u8.MediaPlaylist, err error) {
	if needHeader {
		return makeMediaPlayListWithHeader(from, cdnDomain, origDomain, dirPath, keyUri)
	} else {
		return makeMediaPlayList(from, cdnDomain, dirPath, keyUri, AuthKey)
	}
}

func makeMediaPlayListWithHeader(from *m3u8.MediaPlaylist, cdnDomain, origDomain string, dirPath string, keyUri string) (media *m3u8.MediaPlaylist, err error) {
	media, err = m3u8.NewMediaPlaylist(from.WinSize(), from.Count()+headerMediaPlayList.Count())
	if err != nil {
		return
	}

	//合并片m3u8
	for _, v := range headerMediaPlayList.Segments {
		if v == nil {
			continue
		}
		sg := new(m3u8.MediaSegment)
		sg.URI = v.URI
		if origDomain != "" && strings.HasPrefix(v.URI, origDomain) && origDomain != cdnDomain {
			sg.URI = strings.ReplaceAll(v.URI, origDomain, cdnDomain)
		}
		sg.Title = v.Title
		sg.Duration = v.Duration
		if err = media.AppendSegment(sg); err != nil {
			return
		}
	}

	base := utils.JoinUrlPath(cdnDomain, dirPath)
	for k, segment := range from.Segments {
		if segment == nil {
			continue
		}
		sg := new(m3u8.MediaSegment)
		sg.Discontinuity = k == 0
		sg.URI = utils.JoinUrlPath(base, segment.URI)
		sg.Title = segment.Title
		sg.Duration = segment.Duration
		if err = media.AppendSegment(sg); err != nil {
			return
		}
	}
	_ = media.SetDefaultKey("AES-128", keyUri, "", "", "")
	media.Close()
	return
}