handling empty command, fixing #3

.gitignore

@@ -1,2 +1,3 @@
 bin/
-.idea
+.idea
+.vscode/launch.json

cmd/telegramBot.go

@@ -24,14 +24,15 @@ package cmd
 import (
 	"context"
 	"fmt"
+	"log"
+	"strings"
+
 	tgbotapi "github.com/go-telegram-bot-api/telegram-bot-api/v5"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 	"github.com/zmb3/spotify/v2"
 	spotifyauth "github.com/zmb3/spotify/v2/auth"
 	"golang.org/x/oauth2"
-	"log"
-	"strings"
 )
 
 // telegramBotCmd represents the telegramBot command
@@ -100,34 +101,89 @@ It is not planned to extend this in the future.`,
 						err = viper.WriteConfig()
 						cobra.CheckErr(err)
 					}
-					results, err := client.Search(ctx, strings.TrimPrefix(update.Message.Text, "/spotigram "), spotify.SearchTypeTrack)
-					cobra.CheckErr(err)
 
-					if results != nil {
-						track := results.Tracks.Tracks[0]
-						playlist, err := client.GetPlaylist(ctx, spotify.ID(viper.GetString("spotify_playlist_id")))
+					var results *spotify.SearchResult
+
+					if strings.HasPrefix(update.Message.Text, "/spotigram ") {
+						results, err = client.Search(ctx, strings.TrimPrefix(update.Message.Text, "/spotigram "), spotify.SearchTypeTrack)
 						cobra.CheckErr(err)
+					}
 
-						addTrackResponse, err := client.AddTracksToPlaylist(ctx,
-							playlist.ID,
-							results.Tracks.Tracks[0].ID)
-						cobra.CheckErr(err)
-
-						msg.Text = fmt.Sprintf("Ich habe den Titel <pre>%s</pre> von <pre>%s</pre> zur Playlist <pre>%s</pre> hinzugefügt.",
-							track.Name,
-							track.Artists[0].Name,
-							playlist.Name,
-						)
+					if !strings.HasPrefix(update.Message.Text, "/spotigram ") {
+						msg.Text = "⛔ Ooops, du musst einen Titel angeben!\n <code>/spotigram [Titel]</code>"
 						msg.ParseMode = "HTML"
 						_, err = bot.Send(msg)
 						cobra.CheckErr(err)
 
-						fmt.Printf("New track added to playlist: %s by %s\nsnapshot: %s\n\n",
-							track.Name,
-							track.Artists[0].Name,
-							addTrackResponse)
-
+						fmt.Printf("Command used incorrectly.")
 					}
+
+					if results != nil {
+
+						playlist, err := client.GetPlaylist(ctx, spotify.ID(viper.GetString("spotify_playlist_id")))
+						cobra.CheckErr(err)
+
+						tracks, err := client.GetPlaylistItems(ctx, playlist.ID)
+						cobra.CheckErr(err)
+
+						trackIDs := make([]spotify.ID, 0, len(tracks.Items))
+
+						for page := 1; ; page++ {
+
+							for _, track := range tracks.Items {
+								trackIDs = append(trackIDs, track.Track.Track.ID)
+							}
+
+							err = client.NextPage(ctx, tracks)
+							if err == spotify.ErrNoMorePages {
+								break
+							}
+							if err != nil {
+								cobra.CheckErr(err)
+							}
+						}
+
+						if contains(trackIDs, results.Tracks.Tracks[0].ID) {
+							track := results.Tracks.Tracks[0]
+
+							msg.Text = fmt.Sprintf("⛔ Ooops, dieser Titel ist schon in der Playlist!\n Ich habe den Titel <pre>%s</pre> von <pre>%s</pre> nicht ERNEUT zur Playlist <pre>%s</pre> hinzugefügt.",
+								track.Name,
+								track.Artists[0].Name,
+								playlist.Name,
+							)
+							msg.ParseMode = "HTML"
+							_, err = bot.Send(msg)
+							cobra.CheckErr(err)
+
+							fmt.Printf("Declined adding duplicate track: %s by %s",
+								track.Name,
+								track.Artists[0].Name)
+
+						}
+						if !contains(trackIDs, results.Tracks.Tracks[0].ID) {
+							track := results.Tracks.Tracks[0]
+
+							addTrackResponse, err := client.AddTracksToPlaylist(ctx,
+								playlist.ID,
+								results.Tracks.Tracks[0].ID)
+							cobra.CheckErr(err)
+
+							msg.Text = fmt.Sprintf("Ich habe den Titel <pre>%s</pre> von <pre>%s</pre> zur Playlist <pre>%s</pre> hinzugefügt.",
+								track.Name,
+								track.Artists[0].Name,
+								playlist.Name,
+							)
+							msg.ParseMode = "HTML"
+							_, err = bot.Send(msg)
+							cobra.CheckErr(err)
+
+							fmt.Printf("New track added to playlist: %s by %s\nsnapshot: %s\n\n",
+								track.Name,
+								track.Artists[0].Name,
+								addTrackResponse)
+						}
+					}
+
 				case "rofl":
 					msg.Text = "🤣"
 					_, err = bot.Send(msg)
@@ -156,3 +212,12 @@ func init() {
 	// is called directly, e.g.:
 	// telegramBotCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")
 }
+
+func contains(s []spotify.ID, e spotify.ID) bool {
+	for _, a := range s {
+		if a == e {
+			return true
+		}
+	}
+	return false
+}