From c3f316e67423ad4a6427869823d28146f20bb9de Mon Sep 17 00:00:00 2001
From: Pratyush Desai <pratyush.desai@liberta.casa>
Date: Tue, 19 Jul 2022 06:19:52 +0530
Subject: [PATCH] Initial Commit

---
 .gitignore |   1 +
 go.mod     |   5 ++
 go.sum     |   2 +
 irc.go     | 182 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 190 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 go.mod
 create mode 100644 go.sum
 create mode 100644 irc.go

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..4c49bd7
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+.env
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..af67589
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,5 @@
+module pratyush/wutbot
+
+go 1.18
+
+require github.com/ergochat/irc-go v0.2.0
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..844b752
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,2 @@
+github.com/ergochat/irc-go v0.2.0 h1:3vHdy4c56UTY6+/rTBrQc1fmt32N5G8PrEZacJDOr+E=
+github.com/ergochat/irc-go v0.2.0/go.mod h1:2vi7KNpIPWnReB5hmLpl92eMywQvuIeIIGdt/FQCph0=
diff --git a/irc.go b/irc.go
new file mode 100644
index 0000000..7cf150c
--- /dev/null
+++ b/irc.go
@@ -0,0 +1,182 @@
+package main
+
+import (
+	"crypto/tls"
+	"fmt"
+	"log"
+	"os"
+	"strings"
+
+	"github.com/ergochat/irc-go/ircevent"
+	"github.com/ergochat/irc-go/ircmsg"
+)
+
+type empty struct{}
+
+const (
+	concurrencyLimit = 128
+
+	IRCv3TimestampFormat = "2006-01-02T15:04:05.000Z"
+
+	defaultUserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.81 Safari/537.36"
+
+	replyTagName = "+draft/reply"
+)
+
+type Bot struct {
+	ircevent.Connection
+	TwitterBearerToken string
+	Owner              string
+	semaphore          chan empty
+	userAgent          string
+}
+
+func (b *Bot) tryAcquireSemaphore() bool {
+	select {
+	case b.semaphore <- empty{}:
+		return true
+	default:
+		return false
+	}
+}
+
+func (b *Bot) releaseSemaphore() {
+	<-b.semaphore
+}
+
+func (irc *Bot) checkErr(err error, message string) (fatal bool) {
+	if err != nil {
+		irc.Log.Printf("%s: %v", message, err)
+		return true
+	}
+	return false
+}
+
+// Helper Functions
+
+func (irc *Bot) handleOwnerCommand(target, command string) {
+	if !strings.HasPrefix(command, irc.Nick) {
+		return
+	}
+	command = strings.TrimPrefix(command, irc.Nick)
+	command = strings.TrimPrefix(command, ":")
+	f := strings.Fields(command)
+	if len(f) == 0 {
+		return
+	}
+	switch strings.ToLower(f[0]) {
+	case "abuse":
+		if len(f) > 1 {
+			irc.Privmsg(target, fmt.Sprintf("%s isn't a real programmer", f[1]))
+		}
+	case "quit":
+		irc.Quit()
+	}
+}
+
+func (irc *Bot) sendReplyNotice(target, msgid, text string) {
+	if msgid == "" {
+		irc.Notice(target, text)
+	} else {
+		irc.SendWithTags(map[string]string{replyTagName: msgid}, "NOTICE", target, text)
+	}
+}
+
+func ownerMatches(e ircmsg.Message, owner string) bool {
+	if owner == "" {
+		return false
+	}
+	if present, account := e.GetTag("account"); present && account == owner {
+		return true
+	}
+	return false
+}
+
+func newBot() *Bot {
+	// required:
+	nick := os.Getenv("TITLEBOT_NICK")
+	server := os.Getenv("TITLEBOT_SERVER")
+	// required (comma-delimited list of channels)
+	channels := os.Getenv("TITLEBOT_CHANNELS")
+	// SASL is optional:
+	saslLogin := os.Getenv("TITLEBOT_SASL_LOGIN")
+	saslPassword := os.Getenv("TITLEBOT_SASL_PASSWORD")
+	// a Twitter API key (v2-capable) is optional (if unset, Twitter support is disabled):
+	twitterToken := os.Getenv("TITLEBOT_TWITTER_BEARER_TOKEN")
+	// owner is optional (if unset, titlebot won't accept any owner commands)
+	owner := os.Getenv("TITLEBOT_OWNER_ACCOUNT")
+	// more optional settings
+	version := os.Getenv("TITLEBOT_VERSION")
+	if version == "" {
+		version = "github.com/ergochat/irc-go"
+	}
+	debug := os.Getenv("TITLEBOT_DEBUG") != ""
+	insecure := os.Getenv("TITLEBOT_INSECURE_SKIP_VERIFY") != ""
+	userAgent := os.Getenv("TITLEBOT_USER_AGENT")
+	if userAgent == "" {
+		userAgent = defaultUserAgent
+	}
+
+	var tlsconf *tls.Config
+	if insecure {
+		tlsconf = &tls.Config{InsecureSkipVerify: true}
+	}
+
+	irc := &Bot{
+		Connection: ircevent.Connection{
+			Server:       server,
+			Nick:         nick,
+			UseTLS:       true,
+			TLSConfig:    tlsconf,
+			RequestCaps:  []string{"server-time", "message-tags", "account-tag"},
+			SASLLogin:    saslLogin, // SASL will be enabled automatically if these are set
+			SASLPassword: saslPassword,
+			QuitMessage:  version,
+			Debug:        debug,
+		},
+		TwitterBearerToken: twitterToken,
+		Owner:              owner,
+		userAgent:          userAgent,
+		semaphore:          make(chan empty, concurrencyLimit),
+	}
+
+	irc.AddConnectCallback(func(e ircmsg.Message) {
+		if botMode := irc.ISupport()["BOT"]; botMode != "" {
+			irc.Send("MODE", irc.CurrentNick(), "+"+botMode)
+		}
+		for _, channel := range strings.Split(channels, ",") {
+			irc.Join(strings.TrimSpace(channel))
+		}
+	})
+	irc.AddCallback("PRIVMSG", func(e ircmsg.Message) {
+		target, message := e.Params[0], e.Params[1]
+		_, msgid := e.GetTag("msgid")
+		fromOwner := ownerMatches(e, irc.Owner)
+		if !strings.HasPrefix(target, "#") && !fromOwner {
+			return
+		}
+
+		if fromOwner {
+			irc.handleOwnerCommand(e.Params[0], message)
+		} else if strings.HasPrefix(message, irc.Nick) {
+			irc.sendReplyNotice(e.Params[0], msgid, "don't @ me, mortal")
+		}
+	})
+	irc.AddCallback("INVITE", func(e ircmsg.Message) {
+		fromOwner := ownerMatches(e, irc.Owner)
+		if fromOwner {
+			irc.Join(e.Params[1])
+		}
+	})
+
+	return irc
+}
+
+func main() {
+	irc := newBot()
+	err := irc.Connect()
+	if err != nil {
+		log.Fatal(err)
+	}
+	irc.Loop()
+}