Add simple /ping command

main.go

@@ -0,0 +1,108 @@
+package main
+
+import (
+	"log"
+	"os"
+	"os/signal"
+
+	"github.com/bwmarrin/discordgo"
+	"github.com/joho/godotenv"
+)
+
+// A Session represents a connection to the Discord API.
+var s *discordgo.Session
+
+/*
+/ping - The bot responds with "Pong!".
+*/
+var (
+	commands = []*discordgo.ApplicationCommand{
+		{
+			Name:        "ping",
+			Description: "Pong!",
+		},
+	}
+
+	commandHandlers = map[string]func(s *discordgo.Session, i *discordgo.InteractionCreate){
+		// Ping command
+		"ping": func(s *discordgo.Session, i *discordgo.InteractionCreate) {
+			s.InteractionRespond(i.Interaction, &discordgo.InteractionResponse{
+				Type: discordgo.InteractionResponseChannelMessageWithSource,
+				Data: &discordgo.InteractionResponseData{
+					Content: "Pong!",
+				},
+			})
+		},
+	}
+)
+
+/*
+init() is automatically called when the package is initialized.
+It adds a handler function to the discordgo.Session that is triggered when a slash command is received.
+The handler function checks if the interaction's application command name exists in the commandHandlers map.
+If it does, it calls the corresponding function from the map with the session and interaction as arguments.
+*/
+func init() {
+	// Load .env file.
+	err := godotenv.Load()
+	if err != nil {
+		log.Fatalf("Cannot load .env file: %v", err)
+	}
+
+	// Get the bot token from the environment.
+	token := os.Getenv("TOKEN")
+	if token == "" {
+		log.Fatalln("No token provided. Please set the TOKEN environment variable.")
+	}
+
+	// Create a new Discord session using the provided bot token.
+	s, err = discordgo.New("Bot " + token)
+	if err != nil {
+		log.Fatalf("Cannot create a new Discord session: %v", err)
+	}
+
+	// Add a handler function to the discordgo.Session that is triggered when a slash command is received.
+	s.AddHandler(func(s *discordgo.Session, i *discordgo.InteractionCreate) {
+		if h, ok := commandHandlers[i.ApplicationCommandData().Name]; ok {
+			log.Printf("Handling '%v' command.", i.ApplicationCommandData().Name)
+			h(s, i)
+		}
+	})
+}
+
+func main() {
+	// Print the user we are logging in as.
+	s.AddHandler(func(s *discordgo.Session, _ *discordgo.Ready) {
+		log.Printf("Logged in as: %v#%v", s.State.User.Username, s.State.User.Discriminator)
+	})
+
+	// Open a websocket connection to Discord and begin listening.
+	err := s.Open()
+	if err != nil {
+		log.Fatalf("Cannot open the session: %v", err)
+	}
+
+	// Register the commands.
+	log.Println("Adding commands...")
+	registeredCommands := make([]*discordgo.ApplicationCommand, len(commands))
+	for i, v := range commands {
+		cmd, err := s.ApplicationCommandCreate(s.State.User.ID, "341001473661992962", v)
+		if err != nil {
+			log.Panicf("Cannot create '%v' command: %v", v.Name, err)
+		}
+		registeredCommands[i] = cmd
+		log.Printf("Registered '%v' command.", cmd.Name)
+	}
+
+	// Run s.Close() when the program exits.
+	defer s.Close()
+
+	// Wait here until CTRL-C or other term signal is received.
+	stop := make(chan os.Signal, 1)
+	signal.Notify(stop, os.Interrupt)
+	log.Println("Press Ctrl+C to exit")
+	<-stop
+
+	// Bye bye!
+	log.Println("Gracefully shutting down.")
+}