package dylinkprovider import ( "context" "fmt" "log" "net/http" "net/url" "strconv" "strings" "sync" "time" "gitea.hbanafa.com/hesham/yttopodcast/ytlinkprov" "github.com/lrstanley/go-ytdlp" ) const Q_EXPIRE = "expire" type DynamicCacheExpLinkProvider struct { cache map[string]url.URL l *log.Logger lock *sync.RWMutex } var _ = (ytlinkprov.YtLinkProvider)((*DynamicCacheExpLinkProvider)(nil)) func NewDynCacheExpLinkProv(l *log.Logger) *DynamicCacheExpLinkProvider { p := new(DynamicCacheExpLinkProvider) p.l = l p.lock = &sync.RWMutex{} p.cache = make(map[string]url.URL) ytdlp.MustInstall(context.Background(), &ytdlp.InstallOptions{}) return p } // GetLink implements ytlinkprov.YtLinkProvider. func (d *DynamicCacheExpLinkProvider) GetLink(id string) (link string, err error) { d.lock.RLock() cl1, ok := d.cache[id] d.lock.RUnlock() if ok && !isExpired(cl1) && is200(cl1) { d.l.Printf("[cache] hit on %s\n", id) return cl1.String(), nil } d.l.Printf("[cache] miss on %s\n", id) newlink, err := getRemoteLink(id) if err != nil { return "", err } newlinkurl, err := url.Parse(newlink) if err != nil { return "", err } d.lock.Lock() d.cache[id] = *newlinkurl d.lock.Unlock() d.l.Printf("[cache] new entry for %s\n", id) d.l.Printf("%d items in map\n", len(d.cache)) return newlinkurl.String(), nil } func getRemoteLink(id string) (string, error) { var link string vidUrl := fmt.Sprintf("https://youtube.com/watch?v=%s", id) ytCmd := ytdlp.New().ExtractAudio().GetURL() ytRes, err := ytCmd.Run(context.Background(), vidUrl) if err != nil { return "", err } linkFirst := strings.Split(ytRes.Stdout, "\n")[0] /* Get the last link in a chain of 3XX codes*/ resp, err := http.Get(linkFirst) if err != nil { return "", err } if resp.StatusCode != http.StatusOK { return linkFirst, nil } link = resp.Request.URL.String() return link, nil } func isExpired(link url.URL) bool { exp := link.Query().Get("expire") if exp == "" { return true } tunixd, err := strconv.ParseInt(exp, 10, 64) if err != nil { return true } tunix := time.Unix(tunixd, 0) // If (tunix - now) is negative, the link is expired delta := tunix.Sub(time.Now()) if delta <= 0 { return true } // Still not expired but we check delta against duration durd := 0.0 dur := link.Query().Get("dur") if dur == "" { return true } durd, err = strconv.ParseFloat(exp, 64) if err != nil { return true } if delta < time.Duration(durd) + time.Second * 2400 { return true } return false } func is200(link url.URL) bool { resp, _ := http.Get(link.String()) return resp.StatusCode == 200 }