video.go

package youtube

import (
	"encoding/json"
	"errors"
	"fmt"
	"net/url"
	"strconv"
	"time"
)

type Video struct {
	ID              string
	Title           string
	Description     string
	Author          string
	Duration        time.Duration
	Formats         FormatList
	DASHManifestURL string // URI of the DASH manifest file
	HLSManifestURL  string // URI of the HLS manifest file
}

func (v *Video) parseVideoInfo(info string) error {
	answer, err := url.ParseQuery(info)
	if err != nil {
		return err
	}

	status := answer.Get("status")
	if status != "ok" {
		return &ErrResponseStatus{
			Status: status,
			Reason: answer.Get("reason"),
		}
	}

	// read the streams map
	playerResponse := answer.Get("player_response")
	if playerResponse == "" {
		return errors.New("no player_response found in the server's answer")
	}

	var prData playerResponseData
	if err := json.Unmarshal([]byte(playerResponse), &prData); err != nil {
		return fmt.Errorf("unable to parse player response JSON: %w", err)
	}

	v.Title = prData.VideoDetails.Title
	v.Description = prData.VideoDetails.ShortDescription
	v.Author = prData.VideoDetails.Author

	if seconds, _ := strconv.Atoi(prData.Microformat.PlayerMicroformatRenderer.LengthSeconds); seconds > 0 {
		v.Duration = time.Duration(seconds) * time.Second
	}

	// Check if video is downloadable
	if prData.PlayabilityStatus.Status != "OK" {
		return &ErrPlayabiltyStatus{
			Status: prData.PlayabilityStatus.Status,
			Reason: prData.PlayabilityStatus.Reason,
		}
	}

	// Assign Streams
	v.Formats = append(prData.StreamingData.Formats, prData.StreamingData.AdaptiveFormats...)

	if len(v.Formats) == 0 {
		return errors.New("no formats found in the server's answer")
	}

	v.HLSManifestURL = prData.StreamingData.HlsManifestURL
	v.DASHManifestURL = prData.StreamingData.DashManifestURL

	return nil
}