From c1d69e36304c09869f5948695b87252a3a898d47 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C5=99emysl=20Eric=20Janouch?= <p@janouch.name>
Date: Sun, 30 May 2021 08:06:38 +0200
Subject: [PATCH] degesch: add support for IRCv3 chghost

This is somewhat similar to a nick change.
---
 NEWS      |  2 ++
 degesch.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/NEWS b/NEWS
index 1c1a528..cbc1807 100644
--- a/NEWS
+++ b/NEWS
@@ -7,6 +7,8 @@
 
  * degesch: now supporting IRCv3.2 capability negotiation, including CAP DEL
 
+ * degesch: added support for IRCv3 chghost
+
 
 1.1.0 (2020-10-31) "What Do You Mean By 'This Isn't Germany'?"
 
diff --git a/degesch.c b/degesch.c
index 2033497..0c4310b 100644
--- a/degesch.c
+++ b/degesch.c
@@ -2341,7 +2341,7 @@ static struct config_schema g_config_server[] =
 	  .type      = CONFIG_ITEM_STRING_ARRAY,
 	  .validate  = config_validate_nonjunk_string,
 	  .default_  = "\"multi-prefix,invite-notify,server-time,echo-message,"
-		"message-tags,away-notify,cap-notify\"" },
+		"message-tags,away-notify,cap-notify,chghost\"" },
 
 	{ .name      = "tls",
 	  .comment   = "Whether to use TLS",
@@ -4035,6 +4035,13 @@ log_full (struct app_context *ctx, struct server *s, struct buffer *buffer,
 	log_server ((s), (buffer), BUFFER_LINE_STATUS | BUFFER_LINE_UNIMPORTANT,   \
 		"#n is now known as #n", (old), (new_))
 
+#define log_chghost_self(s, buffer, new_)                                      \
+	log_server ((s), (buffer), BUFFER_LINE_STATUS | BUFFER_LINE_UNIMPORTANT,   \
+		"You are now #N", (new_))
+#define log_chghost(s, buffer, old, new_)                                      \
+	log_server ((s), (buffer), BUFFER_LINE_STATUS | BUFFER_LINE_UNIMPORTANT,   \
+		"#N is now #N", (old), (new_))
+
 #define log_outcoming_notice(s, buffer, who, text)                             \
 	log_server_status ((s), (buffer), "#s(#n): #m", "Notice", (who), (text))
 #define log_outcoming_privmsg(s, buffer, prefixes, who, text)                  \
@@ -6669,6 +6676,52 @@ irc_handle_cap (struct server *s, const struct irc_message *msg)
 	strv_free (&v);
 }
 
+static void
+irc_handle_chghost (struct server *s, const struct irc_message *msg)
+{
+	if (!msg->prefix || msg->params.len < 2)
+		return;
+
+	char *nickname = irc_cut_nickname (msg->prefix);
+	struct user *user = str_map_find (&s->irc_users, nickname);
+	free (nickname);
+	if (!user)
+		return;
+
+	// We don't remember the userhost part, we only log the change
+	char *new_prefix = xstrdup_printf ("%s!%s@%s", user->nickname,
+		msg->params.vector[0], msg->params.vector[1]);
+
+	if (irc_is_this_us (s, msg->prefix))
+	{
+		log_chghost_self (s, s->buffer, new_prefix);
+
+		// Log a message in all open buffers on this server
+		struct str_map_iter iter = str_map_iter_make (&s->irc_buffer_map);
+		struct buffer *buffer;
+		while ((buffer = str_map_iter_next (&iter)))
+			log_chghost_self (s, buffer, new_prefix);
+	}
+	else
+	{
+		// Log a message in any PM buffer
+		struct buffer *buffer =
+			str_map_find (&s->irc_buffer_map, user->nickname);
+		if (buffer)
+			log_chghost (s, buffer, msg->prefix, new_prefix);
+
+		// Log a message in all channels the user is in
+		LIST_FOR_EACH (struct user_channel, iter, user->channels)
+		{
+			buffer = str_map_find (&s->irc_buffer_map, iter->channel->name);
+			hard_assert (buffer != NULL);
+			log_chghost (s, buffer, msg->prefix, new_prefix);
+		}
+	}
+
+	free (new_prefix);
+}
+
 static void
 irc_handle_error (struct server *s, const struct irc_message *msg)
 {
@@ -7310,6 +7363,7 @@ static struct irc_handler g_irc_handlers[] =
 	{ "AUTHENTICATE", irc_handle_authenticate },
 	{ "AWAY",         irc_handle_away         },
 	{ "CAP",          irc_handle_cap          },
+	{ "CHGHOST",      irc_handle_chghost      },
 	{ "ERROR",        irc_handle_error        },
 	{ "INVITE",       irc_handle_invite       },
 	{ "JOIN",         irc_handle_join         },