From c72f7f1e9693218c0ba1368a24dbf52e46a6dbfb Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Tue, 20 Feb 2018 18:09:39 -0800
Subject: [PATCH] ircd::m: Begin an event::errors fundamental conformity
 report.

---
 include/ircd/m/event.h |  38 ++++++++++++
 ircd/m/event.cc        | 133 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 171 insertions(+)

diff --git a/include/ircd/m/event.h b/include/ircd/m/event.h
index 191c1bcf5..16f1db006 100644
--- a/include/ircd/m/event.h
+++ b/include/ircd/m/event.h
@@ -64,6 +64,7 @@ struct ircd::m::event
 {
 	struct prev;
 	struct fetch;
+	struct errors;
 
 	// Common convenience aliases
 	using id = m::id::event;
@@ -128,3 +129,40 @@ struct ircd::m::event::fetch
 	friend bool seek(fetch &, const event::id &, std::nothrow_t);
 	friend void seek(fetch &, const event::id &);
 };
+
+struct ircd::m::event::errors
+{
+	enum code :uint;
+
+	uint64_t report {0};
+
+	bool clean() const;
+	operator bool() const;
+	bool operator!() const;
+	bool has(const uint &code) const;
+	bool has(const code &code) const;
+	string_view string(const mutable_buffer &out) const;
+
+	void set(const code &code);
+	void del(const code &code);
+
+	errors() = default;
+	errors(const event &);
+
+	friend string_view reflect(const code &);
+	friend std::ostream &operator<<(std::ostream &, const errors &);
+};
+
+enum ircd::m::event::errors::code
+:uint
+{
+	INVALID_EVENT_ID,
+	INVALID_ROOM_ID,
+	INVALID_SENDER_ID,
+	INVALID_REDACTS_ID,
+	INVALID_TYPE,
+	DEPTH_NEGATIVE,
+	DEPTH_ZERO_NON_CREATE,
+
+	_NUM_
+};
diff --git a/ircd/m/event.cc b/ircd/m/event.cc
index 84f26d47a..f3d8a96ff 100644
--- a/ircd/m/event.cc
+++ b/ircd/m/event.cc
@@ -501,3 +501,136 @@ const
 {
 	return row.valid(event_id);
 }
+
+//
+// event::errors
+//
+
+namespace ircd::m
+{
+	const size_t event_errors_num{num_of<event::errors::code>()};
+	extern const std::array<string_view, event_errors_num> event_errors_reflects;
+}
+
+decltype(ircd::m::event_errors_reflects)
+ircd::m::event_errors_reflects
+{
+	"INVALID_EVENT_ID",
+	"INVALID_ROOM_ID",
+	"INVALID_SENDER_ID",
+	"INVALID_REDACTS_ID",
+	"DEPTH_NEGATIVE",
+	"DEPTH_ZERO_NON_CREATE",
+};
+
+std::ostream &
+ircd::m::operator<<(std::ostream &s, const event::errors &errors)
+{
+	thread_local char buf[1024];
+	s << errors.string(buf);
+	return s;
+}
+
+ircd::string_view
+ircd::m::reflect(const event::errors::code &code)
+try
+{
+	return event_errors_reflects.at(code);
+}
+catch(const std::out_of_range &e)
+{
+	return "??????"_sv;
+}
+
+ircd::m::event::errors::errors(const event &e)
+:report{0}
+{
+	if(!valid(m::id::EVENT, json::get<"event_id"_>(e)))
+		set(INVALID_EVENT_ID);
+
+	if(!valid(m::id::ROOM, json::get<"room_id"_>(e)))
+		set(INVALID_ROOM_ID);
+
+	if(!valid(m::id::USER, json::get<"sender"_>(e)))
+		set(INVALID_SENDER_ID);
+
+	if(json::get<"type"_>(e) == "m.room.redaction")
+		if(!valid(m::id::EVENT, json::get<"redacts"_>(e)))
+			set(INVALID_REDACTS_ID);
+
+	//TODO: XXX
+	if(empty(json::get<"type"_>(e)))
+		set(INVALID_TYPE);
+
+	if(json::get<"depth"_>(e) < 0)
+		set(DEPTH_NEGATIVE);
+
+	if(json::get<"type"_>(e) != "m.room.create")
+		if(json::get<"depth"_>(e) == 0)
+			set(DEPTH_ZERO_NON_CREATE);
+}
+
+void
+ircd::m::event::errors::del(const code &code)
+{
+	report &= ~(1UL << code);
+}
+
+void
+ircd::m::event::errors::set(const code &code)
+{
+	report |= (1UL << code);
+}
+
+ircd::string_view
+ircd::m::event::errors::string(const mutable_buffer &out)
+const
+{
+	mutable_buffer buf{out};
+	for(uint64_t i(0); i < num_of<code>(); ++i)
+	{
+		if(!has(code(i)))
+			continue;
+
+		if(begin(buf) != begin(out))
+			consume(buf, copy(buf, " "_sv));
+
+		consume(buf, copy(buf, reflect(code(i))));
+	}
+
+	return { data(out), begin(buf) };
+}
+
+bool
+ircd::m::event::errors::has(const code &code)
+const
+{
+	return report & (1UL << code);
+}
+
+bool
+ircd::m::event::errors::has(const uint &code)
+const
+{
+	return (report & (1UL << code)) == code;
+}
+
+bool
+ircd::m::event::errors::operator!()
+const
+{
+	return clean();
+}
+
+ircd::m::event::errors::operator bool()
+const
+{
+	return !clean();
+}
+
+bool
+ircd::m::event::errors::clean()
+const
+{
+	return report == 0;
+}