modules/m_room_history_visibility: Visibility rules for lusers.

modules/m_room_history_visibility.cc

@@ -16,22 +16,111 @@ IRCD_MODULE
 	"Matrix m.room.history_visibility"
 };
 
-namespace ircd::m
+static bool
+_visible_(const m::event &event,
+          const m::user::id &user_id,
+          const m::room &room,
+          const string_view &history_visibility)
 {
-	extern hook::site<> visible_hook;
+	char membership_buf[32];
+	const string_view membership
+	{
+		room.membership(membership_buf, user_id)
+	};
+
+	if(membership == "join")
+		return true;
+
+	if(history_visibility == "joined")
+		return false;
+
+	if(history_visibility == "invited")
+		return membership == "invite";
+
+	assert(history_visibility == "shared");
+	const m::room present{room.room_id};
+	return present.membership(user_id, "join");
 }
 
-decltype(ircd::m::visible_hook)
+static bool
-ircd::m::visible_hook
+_visible_(const m::event &event,
+          const m::node::id &node_id,
+          const m::room &room,
+          const string_view &history_visibility)
 {
-	{ "name", "m.event.visible" }
+	return true;
-};
+}
+
+static bool
+_visible(const m::event &event,
+         const string_view &mxid,
+         const m::room &room,
+         const string_view &history_visibility)
+{
+	if(history_visibility == "world_readable")
+		return true;
+
+	if(empty(mxid))
+		return false;
+
+	switch(m::sigil(mxid))
+	{
+		case m::id::USER:
+			return _visible_(event, m::user::id{mxid}, room, history_visibility);
+
+		case m::id::NODE:
+			return _visible_(event, m::node::id{mxid}, room, history_visibility);
+
+		default: throw m::UNSUPPORTED
+		{
+			"Cannot determine visibility for '%s' mxids",
+			reflect(m::sigil(mxid))
+		};
+	}
+}
 
 extern "C" bool
 visible(const m::event &event,
         const string_view &mxid)
 {
-	return true;
+	const m::room room
+	{
+		at<"room_id"_>(event), at<"event_id"_>(event)
+	};
+
+	static const m::event::fetch::opts fopts
+	{
+		m::event::keys::include{"content"}
+	};
+
+	const m::room::state state
+	{
+		room, &fopts
+	};
+
+	bool ret{false};
+	const bool has_state_event
+	{
+		state.get(std::nothrow, "m.room.history_visibility", "", [&]
+		(const m::event &event)
+		{
+			const json::object &content
+			{
+				json::get<"content"_>(event)
+			};
+
+			const string_view &history_visibility
+			{
+				unquote(content.get("history_visibility", "shared"))
+			};
+
+			ret = _visible(event, mxid, room, history_visibility);
+		})
+	};
+
+	return !has_state_event?
+		_visible(event, mxid, room, "shared"):
+		ret;
 }
 
 static void
@@ -56,18 +145,3 @@ _changed_visibility_hookfn
 		{ "type",     "m.room.history_visibility"  },
 	}
 };
-
-static void
-_event_visible(const m::event &event)
-{
-
-}
-
-const m::hookfn<>
-_event_visible_hookfn
-{
-	_event_visible,
-	{
-		{ "_site",    "m.event.visible"            },
-	}
-};