From d847d55c06c9f1ec5658887da19bf6f2d7417a4c Mon Sep 17 00:00:00 2001
From: Daniel Oaks <daniel@danieloaks.net>
Date: Tue, 9 May 2017 21:09:44 +1000
Subject: [PATCH] Fix wordWrap function so it doesn't drop chars, and fix
 client.Notice() to automagically split very long lines.

---
 irc/client.go | 11 +++++++++--
 irc/server.go | 23 ++++++++++++++++++-----
 2 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/irc/client.go b/irc/client.go
index a2e33d46..079a049a 100644
--- a/irc/client.go
+++ b/irc/client.go
@@ -623,7 +623,14 @@ func (client *Client) Send(tags *map[string]ircmsg.TagValue, prefix string, comm
 }
 
 // Notice sends the client a notice from the server.
-//TODO(dan): Make this handle message splitting.
 func (client *Client) Notice(text string) {
-	client.Send(nil, client.server.name, "NOTICE", client.nick, text)
+	limit := 400
+	if client.capabilities[MaxLine] {
+		limit = client.server.limits.LineLen.Rest - 110
+	}
+	lines := wordWrap(text, limit)
+
+	for _, line := range lines {
+		client.Send(nil, client.server.name, "NOTICE", client.nick, line)
+	}
 }
diff --git a/irc/server.go b/irc/server.go
index d8c7008a..9079f9cb 100644
--- a/irc/server.go
+++ b/irc/server.go
@@ -886,30 +886,43 @@ func topicHandler(server *Server, client *Client, msg ircmsg.IrcMessage) bool {
 	return false
 }
 
+// wordWrap wraps the given text into a series of lines that don't exceed lineWidth characters.
 func wordWrap(text string, lineWidth int) []string {
 	var lines []string
 	var cacheLine, cacheWord string
 
 	for _, char := range text {
-		if (char == ' ' || char == '-') && len(cacheLine)+len(cacheWord)+1 < lineWidth {
+		if char == '\r' {
+			continue
+		} else if char == '\n' {
+			cacheLine += cacheWord
+			lines = append(lines, cacheLine)
+			cacheWord = ""
+			cacheLine = ""
+		} else if (char == ' ' || char == '-') && len(cacheLine)+len(cacheWord)+1 < lineWidth {
+			// natural word boundary
 			cacheLine += cacheWord + string(char)
 			cacheWord = ""
-		} else if len(cacheLine)+len(cacheWord)+1 >= lineWidth {
+		} else if lineWidth <= len(cacheLine)+len(cacheWord)+1 {
+			// time to wrap to next line
 			if len(cacheLine) < (lineWidth / 2) {
-				// there must be a really long word or something, just split on word boundary
+				// this word takes up more than half a line... just split in the middle of the word
 				cacheLine += cacheWord + string(char)
 				cacheWord = ""
+			} else {
+				cacheWord += string(char)
 			}
 			lines = append(lines, cacheLine)
 			cacheLine = ""
 		} else {
+			// normal character
 			cacheWord += string(char)
 		}
 	}
-	if len(cacheWord) > 0 {
+	if 0 < len(cacheWord) {
 		cacheLine += cacheWord
 	}
-	if len(cacheLine) > 0 {
+	if 0 < len(cacheLine) {
 		lines = append(lines, cacheLine)
 	}