From 3ef3cf3b0b355eb4206c4b292fce8729df9db5b7 Mon Sep 17 00:00:00 2001
From: Neale Pickett <neale@woozle.org>
Date: Sat, 19 Jul 2014 00:09:59 +0000
Subject: [PATCH] Welp. Primitive IRC client in go.

---
 irc.go | 176 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 176 insertions(+)
 create mode 100644 irc.go

diff --git a/irc.go b/irc.go
new file mode 100644
index 0000000..b3ec4b0
--- /dev/null
+++ b/irc.go
@@ -0,0 +1,176 @@
+package main
+
+import (
+	"bufio"
+	"crypto/tls"
+	"flag"
+	"fmt"
+	"log"
+	"net"
+	"os"
+	"strings"
+)
+
+type Message struct {
+	Command string
+	FullSender string
+	Sender string
+	Forum string
+	Args []string
+	Text string
+}
+
+func (m Message) String() string {
+	a := append([]string{m.FullSender}, m.Args...)
+	args :=strings.Join(a, " ")
+	return fmt.Sprintf("%s %s %s %s  %s", m.Command, m.Sender, m.Forum, args, m.Text)
+}
+
+func nuhost(s string) (string, string, string) {
+	var parts []string
+
+	parts = strings.SplitN(s, "!", 2)
+	if len(parts) == 1 {
+		return s, "", ""
+	}
+	n := parts[0]
+	parts = strings.SplitN(parts[1], "@", 2)
+	if len(parts) == 1 {
+		return s, "", ""
+	}
+	return n, parts[0], parts[1]
+}
+
+func connect(host string, dotls bool) (net.Conn, error) {
+	if dotls {
+		config := &tls.Config{
+			InsecureSkipVerify: true,
+		}
+		return tls.Dial("tcp", host, config)
+	} else {
+		return net.Dial("tcp", host)
+	}
+}
+
+func readLoop(conn net.Conn, inq chan<- string) {
+	scanner := bufio.NewScanner(conn)
+	for scanner.Scan() {
+		inq <- scanner.Text()
+	}
+	close(inq)
+}
+
+func writeLoop(conn net.Conn, outq <-chan string) {
+	for v := range outq {
+		fmt.Println(v)
+		fmt.Fprintln(conn, v)
+	}
+}
+
+func parse(v string) (Message, error) {
+	var m Message
+	var parts []string
+	var lhs string
+
+	fmt.Println(v)
+	parts = strings.SplitN(v, " :", 2)
+	if len(parts) == 2 {
+		lhs = parts[0]
+		m.Text = parts[1]
+	} else {
+		lhs = v
+		m.Text = ""
+	}
+	
+	m.FullSender = "."
+	m.Forum = "."
+	m.Sender = "."
+
+	parts = strings.Split(lhs, " ")
+	if parts[0][0] == ':' {
+		m.FullSender = parts[0][1:]
+		parts = parts[1:]
+		
+		n, u, _ := nuhost(m.FullSender)
+		if u != "" {
+			m.Sender = n
+		}
+	}
+	
+	m.Command = strings.ToUpper(parts[0])
+	switch (m.Command) {
+	case "PRIVMSG", "NOTICE":
+		n, u, _ := nuhost(parts[1])
+		if u == "" {
+			m.Forum = m.Sender
+		} else {
+			m.Forum = n
+		}
+	case "PART", "MODE", "TOPIC", "KICK":
+		m.Forum = parts[1]
+	case "JOIN":
+		if len(parts) == 1 {
+			m.Forum = m.Text
+			m.Text = ""
+		} else {
+			m.Forum = parts[1]
+		}
+	case "INVITE":
+		if m.Text != "" {
+			m.Forum = m.Text
+			m.Text = ""
+		} else {
+			m.Forum = parts[2]
+		}
+	case "NICK":
+		m.FullSender = parts[1]
+		m.Forum = m.FullSender
+	}
+		
+	return m, nil
+}
+
+func dispatch(outq chan<- string, m Message) {
+	log.Print(m.String())
+	switch (m.Command) {
+	case "PING":
+		outq <- "PONG :" + m.Text
+	}
+}
+
+func usage() {
+	fmt.Fprintf(os.Stderr, "Usage: %s [OPTIONS] HOST:PORT\n", os.Args[0])
+	flag.PrintDefaults()
+}
+
+func main() {
+	dotls := flag.Bool("notls", true, "Disable TLS security")
+
+	flag.Parse()
+	if flag.NArg() != 1 {
+		fmt.Fprintln(os.Stderr, "Error: must specify host")
+		os.Exit(69)
+	}
+
+	conn, err := connect(flag.Arg(0), *dotls)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	inq := make(chan string)
+	outq := make(chan string)
+	go readLoop(conn, inq)
+	go writeLoop(conn, outq)
+
+	outq <- "NICK neale"
+	outq <- "USER neale neale neale :neale"
+	for v := range inq {
+		p, err := parse(v)
+		if err != nil {
+			continue
+		}
+		dispatch(outq, p)
+	}
+
+	close(outq)
+}