helper functions

One for getting the channel id from a user handle.
Another for getting the members playlist id from the channel id.

This is in preparation for making the program function as a quick way to get ids to pass to yt-dlp
to get json data of videos, which in turn will be fed to the program to determine which videos are missing
from an archive

main.go

@@ -5,7 +5,11 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
+	"io"
+	"log"
+	"net/http"
 	"os"
+	"regexp"
 	"sort"
 	"strings"
 )
@@ -75,6 +79,32 @@ func CategoryFlag(name string, value Category, usage string) *Category {
 	return &c
 }
 
+func getChannelID(handle string) string {
+	resp, err := http.Get(fmt.Sprintf("https://www.youtube.com/%s", handle))
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	re := regexp.MustCompile(`<meta[^>]*property=["']og:url["'][^>]*content=["']([^"']+)["']`)
+
+	results := re.FindAllStringSubmatch(string(body), -1)
+	parsedUrl := results[0][1]
+
+	splits := strings.Split(parsedUrl, "/")
+	channelID := splits[len(splits)-1]
+
+	return channelID
+}
+
+func getMembersPlaylistID(channelID string) string {
+	return fmt.Sprintf("UUMO%s", channelID[2:])
+}
+
 func main() {
 	cat := CategoryFlag("category", All, "Category of videos to check against.\nValid options are all, shorts, video, livestream, membership")
 	dumpToFile := flag.Bool("dump-to-file", false, "The program will dump the missing IDs to a file that can be used with yt-dlp")