init commit

bolt.go

@@ -0,0 +1,160 @@
+package bolt
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"strings"
+	"time"
+
+	dg "github.com/bwmarrin/discordgo"
+)
+
+const (
+	TOKEN_ENV_VAR = "DISCORD_TOKEN" //label for token environment variable
+
+	BOT_INTENTS = dg.IntentGuildMembers | //discord permissions for the bot
+		dg.IntentGuildPresences |
+		dg.IntentMessageContent
+)
+
+// basic bot structure containing discordgo connection as well as the command map
+type bolt struct {
+	*dg.Session                    //holds discordgo internals
+	Commands    map[string]Command //maps trigger phrase to command struct for fast lookup
+}
+
+type Bolt interface {
+	Start() error
+	Stop() error
+	AddCommands(cmd Command)
+	messageHandler(s *dg.Session, msg *dg.MessageCreate)
+	createReply(content, message, channel, guild string) *dg.MessageSend
+}
+
+// setup
+func init() {
+	//validate environment variables
+	_, check := os.LookupEnv(TOKEN_ENV_VAR)
+	if !check {
+		log.Fatalf("the %s environment variable must be set", TOKEN_ENV_VAR)
+	}
+}
+
+// create a new bolt interface
+func New() *bolt {
+	bot, err := dg.New(fmt.Sprintf("Bot %s", os.Getenv(TOKEN_ENV_VAR)))
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	bot.Identify.Intents = BOT_INTENTS
+
+	return &bolt{
+		Session: bot,
+	}
+}
+
+// adds command handler and starts the bot
+func (b *bolt) Start() error {
+	//register commands and open connection
+	b.AddHandler(b.messageHandler)
+
+	return b.Open()
+}
+
+// stops the bot
+func (b *bolt) Stop() error {
+	return b.Close()
+}
+
+// adds commands to bot command map for use
+func (b *bolt) AddCommands(cmd ...Command) {
+	for _, c := range cmd {
+		b.Commands[c.Trigger] = c
+	}
+}
+
+// handler function that parses message data and executes any command payloads
+func (b *bolt) messageHandler(s *dg.Session, msg *dg.MessageCreate) {
+	//get server information
+	server, err := s.Guild(msg.GuildID)
+	if err != nil {
+		log.Println(err)
+		return
+	}
+	channel, err := s.Channel(msg.ChannelID)
+	if err != nil {
+		log.Println(err)
+		return
+	}
+
+	//if there is no content it is likely an image or a GIF, updating message content for
+	//better logging and to avoid confusion
+	if len(msg.Content) == 0 {
+		msg.Content = "GIF/IMAGE"
+	}
+
+	//log message
+	log.Printf("< %s | %s | %s > %s\n", server.Name, channel.Name, msg.Author.Username, msg.Content)
+
+	//the bot will ignore it's own messages to prevent command loops
+	if msg.Author.ID == s.State.User.ID {
+		return
+	}
+
+	//does the message have the command indicator "."
+	if msg.Content[:1] == "." {
+		words := strings.Split(msg.Content, " ")
+		run, ok := b.Commands[words[0]]
+		if !ok {
+			return //command doesn't exist, maybe log or respond to author
+		}
+
+		//has command met its timeout requirements
+		if !time.Now().After(run.LastRun.Add(run.Timeout)) {
+			return //running too soon, maybe respond letting know time remaining
+		}
+
+		//run command payload
+		res, err := run.Payload(Message{
+			Author: Author{
+				Username: msg.Author.Username,
+				Roles:    msg.Member.Roles,
+			},
+			Words:   words,
+			Message: msg.Content,
+			Channel: channel.Name,
+			Server:  server.Name,
+		})
+
+		if err != nil {
+			log.Println(err)
+			return
+		}
+
+		//if a reply is returned send back to Discord
+		if res != "" {
+			reply := b.createReply(res, msg.ID, msg.ChannelID, msg.GuildID)
+			_, err := s.ChannelMessageSendComplex(msg.ChannelID, reply)
+			if err != nil {
+				log.Println(err)
+				return
+			}
+		}
+	}
+}
+
+// basic wrapper function to create easy Discord responses
+func (b *bolt) createReply(content, message, channel, guild string) *dg.MessageSend {
+	details := &dg.MessageReference{
+		MessageID: message,
+		ChannelID: channel,
+		GuildID:   guild,
+	}
+
+	return &dg.MessageSend{
+		Content:   content,
+		Reference: details,
+	}
+}