// Matrix Construct
//
// Copyright (C) Matrix Construct Developers, Authors & Contributors
// Copyright (C) 2016-2018 Jason Volk <jason@zemos.net>
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice is present in all copies. The
// full license for this software is available in the LICENSE file.

#include <ircd/m/m.h>

namespace ircd::m
{
	struct log::log log
	{
		"matrix", 'm'
	};

	std::map<std::string, ircd::module> modules;
	std::list<ircd::net::listener> listeners;

	static void leave_ircd_room();
	static void join_ircd_room();
}

const ircd::m::user::id::buf
ircd_user_id
{
	"ircd", ircd::my_host()  //TODO: hostname
};

ircd::m::user
ircd::m::me
{
	ircd_user_id
};

const ircd::m::room::id::buf
ircd_room_id
{
	"ircd", ircd::my_host()
};

ircd::m::room
ircd::m::my_room
{
	ircd_room_id
};

const ircd::m::room::id::buf
control_room_id
{
	"control", ircd::my_host()
};

ircd::m::room
ircd::m::control
{
	control_room_id
};

//
// init
//

ircd::m::init::init()
try
:conf
{
	ircd::conf
}
,_keys
{
	conf
}
{
	modules();
	if(db::sequence(*dbs::events) == 0)
		bootstrap();

	listeners();
	join_ircd_room();
}
catch(const m::error &e)
{
	log.error("%s %s", e.what(), e.content);
	throw;
}
catch(const std::exception &e)
{
	log.error("%s", e.what());
	throw;
}

ircd::m::init::~init()
noexcept try
{
	leave_ircd_room();
	m::listeners.clear();
	m::modules.clear();
}
catch(const m::error &e)
{
	log.critical("%s %s", e.what(), e.content);
	ircd::terminate();
}

void
ircd::m::init::modules()
{
	const string_view prefixes[]
	{
		"m_", "client_", "key_", "federation_", "media_"
	};

	for(const auto &name : mods::available())
		if(startswith_any(name, std::begin(prefixes), std::end(prefixes)))
			m::modules.emplace(name, name);

	m::modules.emplace("root"s, "root"s);
}

namespace ircd::m
{
	static void init_listener(const json::object &conf, const json::object &opts, const string_view &bindaddr);
	static void init_listener(const json::object &conf, const json::object &opts);
}

void
ircd::m::init::listeners()
{
	const json::array listeners
	{
		conf["listeners"]
	};

	if(m::listeners.empty())
		init_listener(conf, {});
	else
		for(const json::object opts : listeners)
			init_listener(conf, opts);
}

static void
ircd::m::init_listener(const json::object &conf,
                       const json::object &opts)
{
	const json::array binds
	{
		opts["bind_addresses"]
	};

	if(binds.empty())
		init_listener(conf, opts, "0.0.0.0");
	else
		for(const auto &bindaddr : binds)
			init_listener(conf, opts, unquote(bindaddr));
}

static void
ircd::m::init_listener(const json::object &conf,
                       const json::object &opts,
                       const string_view &host)
{
	const json::array resources
	{
		opts["resources"]
	};

	// resources has multiple names with different configs which are being
	// ignored :-/
	const std::string name{"Matrix"s};

	// Translate synapse options to our options (which reflect asio::ssl)
	const json::strung options{json::members
	{
		{ "name",                      name                          },
		{ "host",                      host                          },
		{ "port",                      opts.get("port", 8448L)       },
		{ "ssl_certificate_file_pem",  conf["tls_certificate_path"]  },
		{ "ssl_private_key_file_pem",  conf["tls_private_key_path"]  },
		{ "ssl_tmp_dh_file",           conf["tls_dh_params_path"]    },
	}};

	m::listeners.emplace_back(options);
}

void
ircd::m::init::bootstrap()
{
	assert(dbs::events);
	assert(db::sequence(*dbs::events) == 0);

	ircd::log::notice
	(
		"This appears to be your first time running IRCd because the events "
		"database is empty. I will be bootstrapping it with initial events now..."
	);

	create(user::users, me.user_id);
	me.activate();

	create(my_room, me.user_id);
	send(my_room, me.user_id, "m.room.name", "",
	{
		{ "name", "IRCd's Room" }
	});

	send(my_room, me.user_id, "m.room.topic", "",
	{
		{ "topic", "The daemon's den." }
	});

	create(control, me.user_id);
	join(control, me.user_id);
	send(control, me.user_id, "m.room.name", "",
	{
		{ "name", "Control Room" }
	});

	send(user::users, me.user_id, "m.room.name", "",
	{
		{ "name", "Users" }
	});

	create(user::tokens, me.user_id);
	send(user::tokens, me.user_id, "m.room.name", "",
	{
		{ "name", "User Tokens" }
	});

	_keys.bootstrap();

	message(control, me.user_id, "Welcome to the control room.");
	message(control, me.user_id, "I am the daemon. You can talk to me in this room by highlighting me.");
}

bool
ircd::m::self::host(const string_view &s)
{
	return s == host();
}

ircd::string_view
ircd::m::self::host()
{
	return "zemos.net"; //me.user_id.host();
}

void
ircd::m::join_ircd_room()
try
{
	join(my_room, me.user_id);
}
catch(const m::ALREADY_MEMBER &e)
{
	log.warning("IRCd did not shut down correctly...");
}

void
ircd::m::leave_ircd_room()
{
	leave(my_room, me.user_id);
}

///////////////////////////////////////////////////////////////////////////////
//
// m/room.h
//

ircd::m::room
ircd::m::create(const id::room &room_id,
                const id::user &creator,
                const string_view &type)
{
	using prototype = room (const id::room &, const id::user &, const string_view &);

	static import<prototype> function
	{
		"client_createroom", "createroom__type"
	};

	return function(room_id, creator, type);
}

ircd::m::room
ircd::m::create(const id::room &room_id,
                const id::user &creator,
                const id::room &parent,
                const string_view &type)
{
	using prototype = room (const id::room &, const id::user &, const id::room &, const string_view &);

	static import<prototype> function
	{
		"client_createroom", "createroom__parent_type"
	};

	return function(room_id, creator, parent, type);
}

ircd::m::event::id::buf
ircd::m::join(const room &room,
              const id::user &user_id)
{
	using prototype = event::id::buf (const m::room &, const id::user &);

	static import<prototype> function
	{
		"client_rooms", "join__room_user"
	};

	return function(room, user_id);
}

ircd::m::event::id::buf
ircd::m::leave(const room &room,
               const id::user &user_id)
{
	using prototype = event::id::buf (const m::room &, const id::user &);

	static import<prototype> function
	{
		"client_rooms", "leave__room_user"
	};

	return function(room, user_id);
}

ircd::m::event::id::buf
ircd::m::redact(const room &room,
                const id::user &sender,
                const id::event &event_id,
                const string_view &reason)
{
	using prototype = event::id::buf (const m::room &, const id::user &, const id::event &, const string_view &);

	static import<prototype> function
	{
		"client_rooms", "redact__"
	};

	return function(room, sender, event_id, reason);
}

ircd::m::event::id::buf
ircd::m::message(const room &room,
                 const m::id::user &sender,
                 const string_view &body,
                 const string_view &msgtype)
{
	return message(room, sender,
	{
		{ "body",     { body,    json::STRING } },
		{ "msgtype",  { msgtype, json::STRING } },
	});
}

ircd::m::event::id::buf
ircd::m::message(const room &room,
                 const m::id::user &sender,
                 const json::members &contents)
{
	return send(room, sender, "m.room.message", contents);
}

ircd::m::event::id::buf
ircd::m::send(const room &room,
              const m::id::user &sender,
              const string_view &type,
              const string_view &state_key,
              const json::members &contents)
{
	json::iov _content;
	json::iov::push content[contents.size()];
	return send(room, sender, type, state_key, make_iov(_content, content, contents.size(), contents));
}

ircd::m::event::id::buf
ircd::m::send(const room &room,
              const m::id::user &sender,
              const string_view &type,
              const string_view &state_key,
              const json::object &contents)
{
	json::iov _content;
	json::iov::push content[contents.size()];
	return send(room, sender, type, state_key, make_iov(_content, content, contents.size(), contents));
}

ircd::m::event::id::buf
ircd::m::send(const room &room,
              const m::id::user &sender,
              const string_view &type,
              const string_view &state_key,
              const json::iov &content)
{
	using prototype = event::id::buf (const m::room &, const id::user &, const string_view &, const string_view &, const json::iov &);

	static import<prototype> function
	{
		"client_rooms", "state__iov"
	};

	return function(room, sender, type, state_key, content);
}

ircd::m::event::id::buf
ircd::m::send(const room &room,
              const m::id::user &sender,
              const string_view &type,
              const json::members &contents)
{
	json::iov _content;
	json::iov::push content[contents.size()];
	return send(room, sender, type, make_iov(_content, content, contents.size(), contents));
}

ircd::m::event::id::buf
ircd::m::send(const room &room,
              const m::id::user &sender,
              const string_view &type,
              const json::object &contents)
{
	json::iov _content;
	json::iov::push content[contents.count()];
	return send(room, sender, type, make_iov(_content, content, contents.count(), contents));
}

ircd::m::event::id::buf
ircd::m::send(const room &room,
              const m::id::user &sender,
              const string_view &type,
              const json::iov &content)
{
	using prototype = event::id::buf (const m::room &, const id::user &, const string_view &, const json::iov &);

	static import<prototype> function
	{
		"client_rooms", "send__iov"
	};

	return function(room, sender, type, content);
}

ircd::m::event::id::buf
ircd::m::commit(const room &room,
                json::iov &event,
                const json::iov &contents)
{
	using prototype = event::id::buf (const m::room &, json::iov &, const json::iov &);

	static import<prototype> function
	{
		"client_rooms", "commit__iov_iov"
	};

	return function(room, event, contents);
}

ircd::m::id::room::buf
ircd::m::room_id(const id::room_alias &room_alias)
{
	char buf[256];
	return room_id(buf, room_alias);
}

ircd::m::id::room
ircd::m::room_id(const mutable_buffer &out,
                 const id::room_alias &room_alias)
{
	using prototype = id::room (const mutable_buffer &, const id::room_alias &);

	static import<prototype> function
	{
		"client_directory_room", "room_id__room_alias"
	};

	return function(out, room_alias);
}

///////////////////////////////////////////////////////////////////////////////
//
// m/hook.h
//

ircd::m::hook::hook(const json::members &members,
                    decltype(function) function)
try
:_feature
{
	members
}
,feature
{
	_feature
}
,matching
{
	feature
}
,function
{
	std::move(function)
}
,registered
{
	list.add(*this)
}
{
}
catch(...)
{
	if(registered)
		list.del(*this);
}

ircd::m::hook::~hook()
noexcept
{
	if(registered)
		list.del(*this);
}

ircd::string_view
ircd::m::hook::site_name()
const try
{
	return unquote(feature.at("_site"));
}
catch(const std::out_of_range &e)
{
	throw assertive
	{
		"Hook %p must name a '_site' to register with.", this
	};
}

bool
ircd::m::hook::match(const m::event &event)
const
{
	if(json::get<"origin"_>(matching))
		if(at<"origin"_>(matching) != at<"origin"_>(event))
			return false;

	if(json::get<"room_id"_>(matching))
		if(at<"room_id"_>(matching) != at<"room_id"_>(event))
			return false;

	if(json::get<"sender"_>(matching))
		if(at<"sender"_>(matching) != at<"sender"_>(event))
			return false;

	if(json::get<"type"_>(matching))
		if(at<"type"_>(matching) != at<"type"_>(event))
			return false;

	if(json::get<"state_key"_>(matching))
		if(at<"state_key"_>(matching) != json::get<"state_key"_>(event))
			return false;

	if(json::get<"membership"_>(matching))
		if(at<"membership"_>(matching) != json::get<"membership"_>(event))
			return false;

	return true;
}


//
// hook::site
//

ircd::m::hook::site::site(const json::members &members)
try
:_feature
{
	members
}
,feature
{
	_feature
}
,registered
{
	list.add(*this)
}
{
}
catch(...)
{
	if(registered)
		list.del(*this);
}

ircd::m::hook::site::~site()
noexcept
{
	if(registered)
		list.del(*this);
}

void
ircd::m::hook::site::operator()(const event &event)
{
	std::set<hook *> matching;     //TODO: allocator
	const auto site_match{[&matching]
	(auto &map, const string_view &key)
	{
		auto pit{map.equal_range(key)};
		for(; pit.first != pit.second; ++pit.first)
			matching.emplace(pit.first->second);
	}};

	site_match(origin, at<"origin"_>(event));
	site_match(room_id, at<"room_id"_>(event));
	site_match(sender, at<"sender"_>(event));
	site_match(type, at<"type"_>(event));
	if(json::get<"state_key"_>(event))
		site_match(state_key, at<"state_key"_>(event));

	auto it(begin(matching));
	while(it != end(matching))
	{
		const hook &hook(**it);
		if(!hook.match(event))
			it = matching.erase(it);
		else
			++it;
	}

	for(const auto &hook : matching)
		hook->function(event);
}

bool
ircd::m::hook::site::add(hook &hook)
{
	if(json::get<"origin"_>(hook.matching))
		origin.emplace(at<"origin"_>(hook.matching), &hook);

	if(json::get<"room_id"_>(hook.matching))
		room_id.emplace(at<"room_id"_>(hook.matching), &hook);

	if(json::get<"sender"_>(hook.matching))
		sender.emplace(at<"sender"_>(hook.matching), &hook);

	if(json::get<"state_key"_>(hook.matching))
		state_key.emplace(at<"state_key"_>(hook.matching), &hook);

	if(json::get<"type"_>(hook.matching))
		type.emplace(at<"type"_>(hook.matching), &hook);

	++count;
	return true;
}

bool
ircd::m::hook::site::del(hook &hook)
{
	const auto unmap{[&hook]
	(auto &map, const string_view &key)
	{
		auto pit{map.equal_range(key)};
		for(; pit.first != pit.second; ++pit.first)
			if(pit.first->second == &hook)
				return map.erase(pit.first);

		assert(0);
	}};

	if(json::get<"origin"_>(hook.matching))
		unmap(origin, at<"origin"_>(hook.matching));

	if(json::get<"room_id"_>(hook.matching))
		unmap(room_id, at<"room_id"_>(hook.matching));

	if(json::get<"sender"_>(hook.matching))
		unmap(sender, at<"sender"_>(hook.matching));

	if(json::get<"state_key"_>(hook.matching))
		unmap(state_key, at<"state_key"_>(hook.matching));

	if(json::get<"type"_>(hook.matching))
		unmap(type, at<"type"_>(hook.matching));

	--count;
	return true;
}

ircd::string_view
ircd::m::hook::site::name()
const try
{
	return unquote(feature.at("name"));
}
catch(const std::out_of_range &e)
{
	throw assertive
	{
		"Hook site %p requires a name", this
	};
}

//
// hook::list
//

decltype(ircd::m::hook::list)
ircd::m::hook::list
{};

bool
ircd::m::hook::list::del(hook &hook)
try
{
	const auto site(at(hook.site_name()));
	assert(site != nullptr);
	return site->add(hook);
}
catch(const std::out_of_range &e)
{
	log::critical
	{
		"Tried to unregister hook(%p) from missing hook::site '%s'",
		&hook,
		hook.site_name()
	};

	assert(0);
	return false;
}

bool
ircd::m::hook::list::add(hook &hook)
try
{
	const auto site(at(hook.site_name()));
	assert(site != nullptr);
	return site->add(hook);
}
catch(const std::out_of_range &e)
{
	throw error
	{
		"No hook::site named '%s' is registered...", hook.site_name()
	};
}

bool
ircd::m::hook::list::del(site &site)
{
	return erase(site.name());
}

bool
ircd::m::hook::list::add(site &site)
{
	const auto iit
	{
		emplace(site.name(), &site)
	};

	if(unlikely(!iit.second))
		throw error
		{
			"Hook site name '%s' already in use", site.name()
		};

	return true;
}