modules/m_room_power_levels: Add preliminary power eval.

modules/m_room_power_levels.cc

@@ -16,6 +16,94 @@ IRCD_MODULE
 	"Matrix m.room.power_levels"
 };
 
+static void
+_has_power(const m::event &event,
+           m::vm::eval &)
+{
+	const auto &room_id
+	{
+		json::get<"room_id"_>(event)
+	};
+
+	const auto &event_id
+	{
+		json::get<"event_id"_>(event)
+	};
+
+	if(!room_id || !event_id) // Not evaluated here
+		return;
+
+	const auto &type
+	{
+		at<"type"_>(event)
+	};
+
+	if(type == "m.room.create") // Checked by _can_create_room
+		return;
+
+	const m::room room
+	{
+		room_id //TODO: at event
+	};
+
+	const m::user::id &sender
+	{
+		at<"sender"_>(event)
+	};
+
+	//TODO: ircd.presence
+	if(my(event) && my(room) && !my(sender))
+		return;
+
+	const m::room::power power
+	{
+		room
+	};
+
+	const auto &state_key
+	{
+		json::get<"state_key"_>(event)
+	};
+
+	if(!power(sender, "events", type, state_key))
+		log::error //TODO: throw
+		{
+			"Power violation %s in %s for %s %s,%s",
+			string_view{sender},
+			string_view{room_id},
+			string_view{event_id},
+			type,
+			state_key
+		};
+}
+
+const m::hookfn<m::vm::eval &>
+_has_power_hookfn
+{
+	_has_power,
+	{
+		{ "_site", "vm.eval" },
+	}
+};
+
+static void
+_can_change_levels(const m::event &event,
+                   m::vm::eval &)
+{
+	//TODO: abstract event check against existing power levels should
+	//TODO: cover this?
+}
+
+const m::hookfn<m::vm::eval &>
+_can_change_levels_hookfn
+{
+	_can_change_levels,
+	{
+		{ "_site",    "vm.eval"              },
+		{ "type",     "m.room.power_levels"  },
+	}
+};
+
 static void
 _changed_levels(const m::event &event,
                 m::vm::eval &)