From bf01fb7aa3101d061dc9271e6f863f5b634ca408 Mon Sep 17 00:00:00 2001
From: Přemysl Janouch <p.janouch@gmail.com>
Date: Fri, 12 Jun 2015 20:29:21 +0200
Subject: kike: implement the multi-prefix capability

---
 kike.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 67 insertions(+), 16 deletions(-)

diff --git a/kike.c b/kike.c
index 4f9e3cd..948e635 100644
--- a/kike.c
+++ b/kike.c
@@ -293,6 +293,11 @@ enum
 	IRC_USER_MODE_RX_SERVER_NOTICES  = (1 << 4)
 };
 
+enum
+{
+	IRC_CAP_MULTI_PREFIX             = (1 << 0),
+};
+
 struct client
 {
 	LIST_HEADER (struct client)
@@ -314,6 +319,7 @@ struct client
 	bool half_closed;                   ///< Closing link: conn. is half-closed
 
 	unsigned long cap_version;          ///< CAP protocol version
+	unsigned caps;                      ///< Enabled capabilities
 
 	bool ssl_rx_want_tx;                ///< SSL_read() wants to write
 	bool ssl_tx_want_rx;                ///< SSL_write() wants to read
@@ -1140,20 +1146,53 @@ irc_handle_cap (const struct irc_message *msg, struct client *c)
 				subcommand, "Ignoring invalid protocol version number");
 
 		c->cap_negotiating = true;
-		// TODO: actually implement a few capabilities
-		client_send (c, "CAP %s LS :", target);
+		client_send (c, "CAP %s LS :multi-prefix", target);
 	}
 	else if (!irc_strcmp (subcommand, "LIST"))
 	{
-		// TODO: list currently enabled capabilities
-		client_send (c, "CAP %s LIST :", target);
+		struct str_vector caps;
+		str_vector_init (&caps);
+
+		if (c->caps & IRC_CAP_MULTI_PREFIX)
+			str_vector_add (&caps, "multi-prefix");
+
+		char *caps_str = join_str_vector (&caps, ' ');
+		str_vector_free (&caps);
+		client_send (c, "CAP %s LIST :%s", target, caps_str);
+		free (caps_str);
 	}
 	else if (!irc_strcmp (subcommand, "REQ"))
 	{
 		c->cap_negotiating = true;
-		// TODO: process the capability change request, "-" disables
-		if (v.len)
+
+		unsigned new_caps = c->caps;
+		bool success = true;
+		for (size_t i = 0; i < v.len; i++)
+		{
+			bool neg = false;
+			const char *name = v.vector[i];
+			if (*name == '-')
+			{
+				neg = true;
+				name++;
+			}
+			unsigned cap = 0;
+			if (!strcmp (name, "multi-prefix"))
+				cap = IRC_CAP_MULTI_PREFIX;
+			else
+				success = false;
+
+			if (neg)
+				new_caps &= ~cap;
+			else
+				new_caps |=  cap;
+		}
+
+		if (success)
+		{
+			c->caps = new_caps;
 			client_send (c, "CAP %s NAK :%s", target, params);
+		}
 		else
 			client_send (c, "CAP %s ACK :%s", target, params);
 	}
@@ -1943,6 +1982,26 @@ irc_handle_list (const struct irc_message *msg, struct client *c)
 	irc_send_reply (c, IRC_RPL_LISTEND);
 }
 
+static void
+irc_append_prefixes (struct client *c, struct channel_user *user,
+	struct str *output)
+{
+	struct str prefixes;
+	str_init (&prefixes);
+
+	if (user->modes & IRC_CHAN_MODE_OPERATOR)  str_append_c (&prefixes, '@');
+	if (user->modes & IRC_CHAN_MODE_VOICE)     str_append_c (&prefixes, '+');
+
+	if (prefixes.len)
+	{
+		if (c->caps & IRC_CAP_MULTI_PREFIX)
+			str_append   (output, prefixes.str);
+		else
+			str_append_c (output, prefixes.str[0]);
+	}
+	str_free (&prefixes);
+}
+
 static void
 irc_send_rpl_namreply (struct client *c, const struct channel *chan)
 {
@@ -1963,10 +2022,7 @@ irc_send_rpl_namreply (struct client *c, const struct channel *chan)
 
 		struct str result;
 		str_init (&result);
-		if (iter->modes & IRC_CHAN_MODE_OPERATOR)
-			str_append_c (&result, '@');
-		else if (iter->modes & IRC_CHAN_MODE_VOICE)
-			str_append_c (&result, '+');
+		irc_append_prefixes (c, iter, &result);
 		str_append (&result, iter->c->nickname);
 		str_vector_add_owned (&nicks, str_steal (&result));
 	}
@@ -2029,12 +2085,7 @@ irc_send_rpl_whoreply (struct client *c, const struct channel *chan,
 
 	struct channel_user *user;
 	if (chan && (user = channel_get_user (chan, target)))
-	{
-		if (user->modes & IRC_CHAN_MODE_OPERATOR)
-			str_append_c (&chars, '@');
-		else if (user->modes & IRC_CHAN_MODE_VOICE)
-			str_append_c (&chars, '+');
-	}
+		irc_append_prefixes (c, user, &chars);
 
 	irc_send_reply (c, IRC_RPL_WHOREPLY, chan ? chan->name : "*",
 		target->username, target->hostname, target->ctx->server_name,
-- 
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