censor.lua: strip colours, configurable formatting

Colour parsing code taken from prime.lua, and modified to strip.

NEWS

@@ -9,6 +9,9 @@
 
  * degesch: added support for IRCv3 chghost
 
+ * censor.lua: now stripping colours from censored messages;
+   their attributes are also configurable rather than always black on black
+
 
 1.1.0 (2020-10-31) "What Do You Mean By 'This Isn't Germany'?"
 

plugins/degesch/censor.lua

@@ -1,7 +1,7 @@
 --
 -- censor.lua: black out certain users' messages
 --
--- Copyright (c) 2016, Přemysl Eric Janouch <p@janouch.name>
+-- Copyright (c) 2016 - 2021, Přemysl Eric Janouch <p@janouch.name>
 --
 -- Permission to use, copy, modify, and/or distribute this software for any
 -- purpose with or without fee is hereby granted.
@@ -38,6 +38,7 @@ local read_masks = function (v)
 	end
 end
 
+local quote
 degesch.setup_config {
 	masks = {
 		type = "string_array",
@@ -45,13 +46,29 @@ degesch.setup_config {
 		comment = "user masks (optionally \"/#channel\") to censor",
 		on_change = read_masks
 	},
+	quote = {
+		type = "string",
+		default = "\"\\x0301,01\"",
+		comment = "formatting prefix for censored messages",
+		on_change = function (v) quote = v end
+	},
 }
 
+local decolor = function (text)
+	local rebuilt, last = {""}, 1
+	for start in text:gmatch ('()\x03') do
+		table.insert (rebuilt, text:sub (last, start - 1))
+		local sub = text:sub (start + 1)
+		last = start + (sub:match ('^%d%d?,%d%d?()') or sub:match ('^%d?%d?()'))
+	end
+	return table.concat (rebuilt) .. text:sub (last)
+end
+
 local censor = function (line)
 	-- Taking a shortcut to avoid lengthy message reassembly
 	local start, text = line:match ("^(.- PRIVMSG .- :)(.*)$")
 	local ctcp, rest = text:match ("^(\x01%g+ )(.*)")
-	text = ctcp and ctcp .. "\x0301,01" .. rest or "\x0301,01" .. text
+	text = ctcp and ctcp .. quote .. decolor (rest) or quote .. decolor (text)
 	return start .. text
 end