ircd::m::push: Implement event_property_is. (matrix-org/matrix-spec-proposals#3758)

Author: jevolk

include/ircd/m/name.h

@@ -191,6 +191,7 @@ struct ircd::m::name
 	static constexpr const char *const pattern {"pattern"};
 	static constexpr const char *const is {"is"};
 	static constexpr const char *const cond {"cond"};
+	static constexpr const char *const value {"value"};
 
 	static constexpr const char *const actions {"actions"};
 	static constexpr const char *const default_ {"default"};

include/ircd/m/push.h

@@ -64,8 +64,8 @@ struct ircd::m::push::match
 	struct opts;
 	using cond_kind_func = bool (*)(const event &, const cond &, const opts &);
 
-	static const string_view cond_kind_name[6];
-	static const cond_kind_func cond_kind[7];
+	static const string_view cond_kind_name[];
+	static const cond_kind_func cond_kind[];
 
 	explicit match(const event &, const cond &, const opts &);
 	explicit match(const event &, const rule &, const opts &);
@@ -217,7 +217,11 @@ struct ircd::m::push::cond
 	/// prefixed by one of, ==, <, >, >= or <=. A prefix of < matches rooms
 	/// where the member count is strictly less than the given number and so
 	/// forth. If no prefix is present, this parameter defaults to ==.
-	json::property<name::is, json::string>
+	json::property<name::is, json::string>,
+
+	/// Required for event_property conditions. The exact case-sensitive string
+	/// to match.
+	json::property<name::value, json::string>
 >
 {
 	using super_type::tuple;

matrix/name.cc

@@ -170,6 +170,7 @@ constexpr const char *const ircd::m::name::key;
 constexpr const char *const ircd::m::name::pattern;
 constexpr const char *const ircd::m::name::is;
 constexpr const char *const ircd::m::name::cond;
+constexpr const char *const ircd::m::name::value;
 
 constexpr const char *const ircd::m::name::actions;
 constexpr const char *const ircd::m::name::default_;

matrix/push.cc

@@ -77,13 +77,15 @@ namespace ircd::m::push
 	static bool state_key_user_mxid(const event &, const cond &, const match::opts &);
 	static bool contains_user_mxid(const event &, const cond &, const match::opts &);
 	static bool room_member_count(const event &, const cond &, const match::opts &);
+	static bool event_property_is(const event &, const cond &, const match::opts &);
 	static bool event_match(const event &, const cond &, const match::opts &);
 }
 
 decltype(ircd::m::push::match::cond_kind)
 ircd::m::push::match::cond_kind
 {
 	event_match,
+	event_property_is,
 	room_member_count,
 	contains_user_mxid,
 	state_key_user_mxid,
@@ -96,6 +98,7 @@ decltype(ircd::m::push::match::cond_kind_name)
 ircd::m::push::match::cond_kind_name
 {
 	"event_match",
+	"event_property_is",
 	"room_member_count",
 	"contains_user_mxid",
 	"state_key_user_mxid",
@@ -220,6 +223,61 @@ catch(const std::exception &e)
 	return false;
 }
 
+bool
+ircd::m::push::event_property_is(const event &event,
+                                 const cond &cond,
+                                 const match::opts &opts)
+try
+{
+	assert(json::get<"kind"_>(cond) == "event_property_is");
+
+	const auto &[top, path]
+	{
+		split(json::get<"key"_>(cond), '.')
+	};
+
+	string_view value
+	{
+		json::get(event, top, json::object{})
+	};
+
+	tokens(path, '.', [&value]
+	(const string_view &key)
+	{
+		if(!json::type(value, json::OBJECT))
+			return false;
+
+		value = json::object(value)[key];
+		if(likely(!json::type(value, json::STRING)))
+			return true;
+
+		value = json::string(value);
+		return false;
+	});
+
+	const json::value a{value}, b
+	{
+		json::get<"value"_>(cond)
+	};
+
+	return a == b;
+}
+catch(const ctx::interrupted &)
+{
+	throw;
+}
+catch(const std::exception &e)
+{
+	log::error
+	{
+		log, "Push condition 'event_property_is' %s :%s",
+		string_view{event.event_id},
+		e.what(),
+	};
+
+	return false;
+}
+
 bool
 ircd::m::push::contains_user_mxid(const event &event,
                                   const cond &cond,