re-run slash command by button

demo.go

/*
USAGE:
-guild=987654321987654321 -token=xxxxx.oooo -rmcmd=true

腳本說明:
當使用者輸入 `/joke` 指令，可以選擇要看哪一則笑話(由chatgpt所提供)，
看完之後會出現一個按鈕，可以查看下一則笑話(已經到尾就再從頭開始)
*/

package main

import (
	"encoding/json"
	"flag"
	"fmt"
	"github.com/bwmarrin/discordgo"
	"log"
	"os"
	"os/signal"
	"time"
)

var (
	GuildID        = flag.String("guild", "", "Test guild ID. If not passed - bot registers commands globally")
	BotToken       = flag.String("token", "", "Bot access token: https://discord.com/developers/applications/123456789012345678/bot")
	RemoveCommands = flag.Bool("rmcmd", false, "Remove all commands after shutdowning or not")
)

var s *discordgo.Session

func init() { flag.Parse() }

func init() {
	var err error
	s, err = discordgo.New("Bot " + *BotToken) // 利用Token找到您的機器人
	if err != nil {
		log.Fatalf("Invalid bot parameters: %v", err)
	}
}

var (
	integerOptionMinValue = 0.0

	commands = []*discordgo.ApplicationCommand{
		{
			Name:        "joke",
			Description: "看笑話",
			Options: []*discordgo.ApplicationCommandOption{
				{
					Name:        "n",
					Type:        discordgo.ApplicationCommandOptionInteger,
					MinValue:    &integerOptionMinValue,
					MaxValue:    4,
					Description: "第幾則笑話",
					Required:    true,
				},
			},
		},
	}

	jokes = []string{
		"Why don’t skeletons fight each other? They don’t have the guts!",
		"為什麼糖是方的？因為它是方糖！",
		"為什麼樹木不喜歡玩隱藏？因為它們害怕被砍掉！",
		"雞看到火車來了，為什麼不跑？因為它是火雞！",
		"為什麼餅乾總是失敗？因為它總是碎了大事！",
	}
	jokeHandler = func(s *discordgo.Session, i *discordgo.InteractionCreate) {
		n := i.ApplicationCommandData().Options[0].IntValue()
		if err := s.InteractionRespond(i.Interaction, &discordgo.InteractionResponse{
			Type: discordgo.InteractionResponseChannelMessageWithSource,
			Data: &discordgo.InteractionResponseData{
				Content: jokes[n],
			},
		}); err != nil {
			_, _ = s.FollowupMessageCreate(i.Interaction, true, &discordgo.WebhookParams{
				Content: "Something went wrong",
			})
			return
		}
		time.AfterFunc(2*time.Second, func() {
			/* 可以考慮把輸入參數寫在檔案之中
			paraFile := &discordgo.File{
				Name:        "userInputPara.json",
				ContentType: "application/json",
				Reader:      bytes.NewBuffer([]byte(fmt.Sprintf(`{"n":%d}`, n))),
			}
			*/
			_, _ = s.InteractionResponseEdit(i.Interaction, &discordgo.WebhookEdit{
				Content: jokes[n],
				/*
					Files: []*discordgo.File{
						paraFile,
					},
				*/
				Components: []discordgo.MessageComponent{
					discordgo.ActionsRow{
						Components: []discordgo.MessageComponent{
							discordgo.Button{
								Emoji: discordgo.ComponentEmoji{
									Name: "🔄",
								},
								Label: "看下一則笑話",
								Style: discordgo.PrimaryButton,
								// URL:      fmt.Sprintf(`{"n":%d}`, n), // 用URL來充當Value, 後面會有問題，不曉得甚麼原因，總之行不通
								CustomID: "re_joke",
							},
							discordgo.Button{
								Emoji: discordgo.ComponentEmoji{
									Name: "ℹ️",
								},
								Label: "google search",
								Style: discordgo.LinkButton,
								URL:   "https://www.google.com/search?q=joke",
							},
							discordgo.Button{
								Label:    fmt.Sprintf(`{"n":%d}`, n),
								Style:    discordgo.SecondaryButton,
								CustomID: "test",
							},
						},
					},
				},
			})
		})
	}

	// 實作各個commands所要做的事情
	commandHandlers = map[string]func(s *discordgo.Session, i *discordgo.InteractionCreate){
		"joke": jokeHandler,
	}
)

func init() {
	s.AddHandler(func(s *discordgo.Session, i *discordgo.InteractionCreate) {
		switch i.Type {
		case discordgo.InteractionApplicationCommand:
			if handlerFunc, exists := commandHandlers[i.ApplicationCommandData().Name]; exists {
				handlerFunc(s, i)
			}
		case discordgo.InteractionMessageComponent:
			componentsHandlers := map[string]func(s *discordgo.Session, i *discordgo.InteractionCreate){
				"re_joke": jokeHandler,
			}
			if handlerFunc, exists := componentsHandlers[i.MessageComponentData().CustomID]; exists {

				var jokePara struct {
					N float64
				}

				if err := json.Unmarshal([]byte(i.Message.Components[0].(*discordgo.ActionsRow).Components[2].(*discordgo.Button).Label), &jokePara); err != nil {
					fmt.Println(err)
					return
				}

				/*
					if len(i.Message.Attachments) > 0 {
						attachment := i.Message.Attachments[0]
						http.Get(attachment.URL)
					}
				*/

				// 這邊可以硬把i改成InteractionApplicationCommand時的i內容
				i.Type = discordgo.InteractionApplicationCommandAutocomplete
				n := jokePara.N + 1 // 看下一則笑話
				if int(n) >= len(jokes) {
					n = 0
				}
				i.Data = discordgo.ApplicationCommandInteractionData{
					Options: []*discordgo.ApplicationCommandInteractionDataOption{
						{
							Name:  "n",
							Type:  discordgo.ApplicationCommandOptionInteger,
							Value: n,
						},
					},
				}
				handlerFunc(s, i)
			}
		}
	})
}

func main() {
	err := s.Open()
	if err != nil {
		panic(err)
	}
	defer func() {
		_ = s.Close()
	}()

	log.Println("Adding commands...")
	registeredCommands := make([]*discordgo.ApplicationCommand, len(commands))
	for i, v := range commands {
		cmd, err := s.ApplicationCommandCreate(s.State.User.ID, *GuildID, v)
		if err != nil {
			log.Panicf("Cannot create '%v' command: %v", v.Name, err)
		}
		registeredCommands[i] = cmd
	}

	defer func() {
		_ = s.Close()
	}()

	stop := make(chan os.Signal, 1)
	signal.Notify(stop, os.Interrupt)
	log.Println("Press Ctrl+C to exit")
	<-stop

	if *RemoveCommands {
		log.Println("Removing commands...")
		for _, v := range registeredCommands {
			err := s.ApplicationCommandDelete(s.State.User.ID, *GuildID, v.ID)
			if err != nil {
				log.Panicf("Cannot delete '%v' command: %v", v.Name, err)
			}
		}
	}
	log.Println("Gracefully shutting down.")
}