From 4b848c812dee16dd241aafd458edd37eec150baa Mon Sep 17 00:00:00 2001
From: Jack <jack@anarchyplanet.org>
Date: Wed, 14 Jul 2021 22:42:11 +0000
Subject: [PATCH] Added IRC message parser, used to generalize code

---
 main.go | 74 +++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 64 insertions(+), 10 deletions(-)

diff --git a/main.go b/main.go
index fe8a891..c23aaf9 100644
--- a/main.go
+++ b/main.go
@@ -14,6 +14,7 @@ var nick = "pathbbot"
 func sendData(conn net.Conn, message string) {
 	fmt.Fprintf(conn, "%s\n", message)
 }
+
 func logon(conn net.Conn) {
 	sendData(conn, "NICK "+nick)
 	sendData(conn, "User inhabitant 8 * : pathbwalker")
@@ -25,7 +26,6 @@ func sendPong(conn net.Conn, ping string) {
 
 func join(conn net.Conn) {
 	sendData(conn, "JOIN #pathb")
-
 }
 
 func main() {
@@ -35,26 +35,80 @@ func main() {
 	}
 
 	reader := bufio.NewReader(conn)
+
 	logon(conn)
 	for {
 		ln, err := reader.ReadString('\n')
-		ln = strings.Trim(ln, "\n")
-		log.Println(ln)
+		fmt.Print(ln)
 
-		switch {
-		case err == io.EOF:
+		var _, command, _, message = parseIRCMessage(ln)
+
+		switch err {
+		case io.EOF:
 			log.Println("Reached EOF - closing this connection.\n")
 			return
-		case err != nil:
+		case nil: // Do nothing
+			break
+		default:
 			log.Println("error.\n")
 			return
-		case strings.Contains(ln, "PING"):
+		}
+
+		switch {
+		case command == "PING":
 			sendPong(conn, ln)
-		case strings.Contains(ln, "001 "+nick+" :Welcome"):
+		case command == "001":
 			join(conn)
-		case strings.Contains(ln, "@arise"):
-			sendData(conn, "PRIVMSG #pathb :What the fuck did you just fucking say about me, you little bitch? I'll have you know I graduated top of my class in the Navy Seals, and I've been involved in numerous secret raids on Al-Quaeda, and I have over 300 confirmed kills. I am trained in gorilla warfare and I'm the top sniper in the entire US armed forces. You are nothing to me but just another target. I will wipe you the fuck out with precision the likes of which has never been seen before on this Earth, mark my fucking words. ")
+		case command == "PRIVMSG" && message == "@arise":
+			sendData(conn, "PRIVMSG #pathb :What the fuck did you just fucking say about me, you little bitch? I'll have you know I graduated top of my class in the Navy Seals, and I've been involved in numerous secret raids on Al-Quaeda, and I have over 300 confirmed kills. I am trained in gorilla warfare and I'm the top sniper in the entire US armed forces. You are nothing to me but just another target. I will wipe you the fuck out with precision the likes of which has never been seen before on this Earth, mark my fucking words.")
 		}
 
 	}
 }
+
+/***
+ * Parses a recieved IRC message into its components.
+ *
+ * Returns:
+ * prefix string - optional prefix, empty string if not
+ * command string - command
+ * params []string - params, separated into a slice. If final param form is present,
+ *		it is returned with its preceeding ':'
+ * text string - if final param form is present, return final param string without
+ *		preceeding ':'
+ */
+func parseIRCMessage(message string) (prefix, command string, params []string, text string) {
+	var lineReader = bufio.NewReader(strings.NewReader(strings.Trim(message, "\n")))
+
+	// Optionally scan prefix into prefix
+	if message[0] == ':' {
+		fmt.Fscanf(lineReader, ":%s ", &prefix)
+	}
+
+	// Scan first non prefix string into command
+	fmt.Fscanf(lineReader, "%s ", &command)
+
+	// Scan rest of line into args
+	for lineReader.Buffered() > 0 {
+
+		var param string
+
+		// Peek the first character, if it's a ':' this is the last parameter,
+		// which includes spaces
+		if char, _ := lineReader.Peek(1); char[0] == ':' {
+			var paramBytes, _ = io.ReadAll(lineReader)
+			param = string(paramBytes)
+
+			// Text is defined as the last parameter sans ':', if the special
+			// Last parameter exists
+			text = strings.TrimPrefix(param, ":")
+		} else {
+			var paramBytes, _ = lineReader.ReadString(' ')
+			param = string(paramBytes)
+		}
+
+		params = append(params, param)
+	}
+
+	return prefix, command, params, text
+}