add new youtubedl dependency

downloader/vendor/github.com/kkdai/youtube/v2/player_parse.go

@@ -0,0 +1,59 @@
+package youtube
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+)
+
+type playerConfig []byte
+
+var basejsPattern = regexp.MustCompile(`(/s/player/\w+/player_ias.vflset/\w+/base.js)`)
+
+func (c *Client) getPlayerConfig(ctx context.Context, videoID string) (playerConfig, error) {
+	embedURL := fmt.Sprintf("https://youtube.com/embed/%s?hl=en", videoID)
+	embedBody, err := c.httpGetBodyBytes(ctx, embedURL)
+	if err != nil {
+		return nil, err
+	}
+
+	// example: /s/player/f676c671/player_ias.vflset/en_US/base.js
+	playerPath := string(basejsPattern.Find(embedBody))
+	if playerPath == "" {
+		return nil, errors.New("unable to find basejs URL in playerConfig")
+	}
+
+	// for debugging
+	var artifactName string
+	if artifactsFolder != "" {
+		parts := strings.SplitN(playerPath, "/", 5)
+		artifactName = "player-" + parts[3] + ".js"
+		linkName := filepath.Join(artifactsFolder, "video-"+videoID+".js")
+		if err := os.Symlink(artifactName, linkName); err != nil {
+			log.Printf("unable to create symlink %s: %v", linkName, err)
+		}
+	}
+
+	config := c.playerCache.Get(playerPath)
+	if config != nil {
+		return config, nil
+	}
+
+	config, err = c.httpGetBodyBytes(ctx, "https://youtube.com"+playerPath)
+	if err != nil {
+		return nil, err
+	}
+
+	// for debugging
+	if artifactName != "" {
+		writeArtifact(artifactName, config)
+	}
+
+	c.playerCache.Set(playerPath, config)
+	return config, nil
+}