automatic youtube subscription refreshing

Author: Kesuaheli

event/event.go

@@ -33,6 +33,6 @@ func AddListeners(s *discordgo.Session) {
 	addCommandListeners(s)
 	addVoiceStateListeners(s)
 
-	addScheduledTriggers(s)
 	addYouTubeListeners(s)
+	addScheduledTriggers(s)
 }

event/scheduledTriggers.go

@@ -18,13 +18,15 @@ import (
 	"time"
 
 	"cake4everybot/event/command/birthday"
+	webYT "cake4everybot/webserver/youtube"
 
 	"github.com/bwmarrin/discordgo"
 	"github.com/spf13/viper"
 )
 
 func addScheduledTriggers(s *discordgo.Session) {
 	go scheduleBirthdayCheck(s)
+	go refreshYoutube()
 }
 
 func scheduleBirthdayCheck(s *discordgo.Session) {
@@ -43,3 +45,12 @@ func scheduleBirthdayCheck(s *discordgo.Session) {
 		birthday.Check(s)
 	}
 }
+
+func refreshYoutube() {
+	for {
+		webYT.RefreshSubscriptions()
+
+		// loop every 4 days
+		time.Sleep(4 * 24 * time.Hour)
+	}
+}

webserver/youtube/discord.go

@@ -15,7 +15,9 @@
 package youtube
 
 import (
+	"fmt"
 	"log"
+	"net/http"
 
 	"github.com/bwmarrin/discordgo"
 )
@@ -53,3 +55,34 @@ func UnsubscribeChannel(channelID string) {
 		log.Printf("YouTube: unsubscribed '%s' from announcements", channelID)
 	}
 }
+
+// RefreshSubscriptions sends a subscription request to the youtube hub
+func RefreshSubscriptions() {
+	for id := range subscribtions {
+		log.Printf("[YouTube] Requesting refresh subscription for id '%s'...", id)
+
+		url := "https://pubsubhubbub.appspot.com/subscribe"
+		req, err := http.NewRequest(http.MethodGet, url, nil)
+		if err != nil {
+			log.Printf("Error on creating refresh subscription: %v", err)
+			continue
+		}
+
+		req.Form.Set("hub.callback", "https://webhook.cake4everyone.de/api/yt_pubsubhubbub")
+		req.Form.Set("hub.topic", fmt.Sprintf("https://www.youtube.com/xml/feeds/videos.xml?channel_id=%s", id))
+		req.Form.Set("hub.verify", "sync")
+		req.Form.Set("hub.mode", "subscribeconst")
+
+		resp, err := http.DefaultClient.Do(req)
+		if err != nil {
+			log.Printf("[YouTube] Refresh request failed: %v", err)
+		}
+
+		if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+			log.Printf("[YouTube] Refreshing for channel '%s' failed with status %d", id, resp.StatusCode)
+			continue
+		}
+
+		log.Printf("[YouTube] Successfully refreshed subscription for channel '%s'", id)
+	}
+}