// 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.

ircd::mapi::header
IRCD_MODULE
{
	"Matrix rooms interface; modular components"
};

decltype(ircd::m::rooms::opts_default)
ircd::m::rooms::opts_default;

bool
IRCD_MODULE_EXPORT
ircd::m::rooms::has(const opts &opts)
{
	return !for_each(opts, []
	(const m::room::id &)
	{
		// false to break; for_each() returns false
		return false;
	});
}

size_t
IRCD_MODULE_EXPORT
ircd::m::rooms::count(const opts &opts)
{
	size_t ret{0};
	for_each(opts, [&ret]
	(const m::room::id &)
	{
		++ret;
		return true;
	});

	return ret;
}

bool
IRCD_MODULE_EXPORT
ircd::m::rooms::for_each(const room::id::closure_bool &closure)
{
	return for_each(opts_default, closure);
}

bool
IRCD_MODULE_EXPORT
ircd::m::rooms::for_each(const opts &opts,
                         const room::id::closure_bool &closure)
{
	bool ret{true};
	const auto proffer{[&opts, &closure, &ret]
	(const m::room::id &room_id)
	{
		if(opts.room_id && !opts.lower_bound)
		{
			ret = false;
			return;
		}

		const m::room room
		{
			room_id
		};

		if(opts.room_id)
			if(room_id < opts.room_id)
				return;

		if(opts.local_joined_only)
			if(!local_joined(room))
				return;

		if(opts.remote_joined_only)
			if(!remote_joined(room))
				return;

		if(opts.local_only)
			if(!local_only(room))
				return;

		if(opts.remote_only)
			if(local_only(room))
				return;

		if(opts.server && !opts.summary)
			if(opts.server != room_id.host())
				return;

		if(opts.summary)
			if(!summary::has(room))
				return;

		if(opts.server && opts.summary)
			if(!room::aliases(room).count(opts.server))
				return;

		if(opts.join_rule && !opts.summary)
			if(!join_rule(room, opts.join_rule))
				return;

		if(opts.room_alias)
		{
			const auto match_alias_prefix{[&opts](const auto &alias)
			{
				return !startswith(alias, opts.room_alias);
			}};

			if(room::aliases(room).for_each(match_alias_prefix))
				return; // no match
		}

		ret = closure(room);
	}};

	// branch for public rooms of a specific user
	if(opts.user_id)
	{
		const user::rooms user_rooms
		{
			opts.user_id
		};

		return user_rooms.for_each(user::rooms::closure_bool{[&proffer, &ret]
		(const room::id &room_id, const string_view &membership)
		{
			proffer(room_id);
			return ret;
		}});
	}

	// branch for optimized public rooms searches.
	if(opts.summary && opts.server)
	{
		m::room::aliases::cache::for_each(opts.server, [&proffer, &ret]
		(const auto &alias, const auto &room_id)
		{
			if(!m::rooms::summary::has(room_id))
				return true;

			proffer(room_id);
			return ret;
		});

		return ret;
	}

	// branch for optimized public rooms searches.
	if(opts.summary)
	{
		const room::id::buf public_room_id
		{
			"!public", my_host()
		};

		const room::state state
		{
			public_room_id
		};

		const auto proffer_state{[&opts, &proffer, &ret]
		(const string_view &type, const string_view &state_key, const event::idx &event_idx)
		{
			room::id::buf buf;
			const auto &room_id
			{
				room::id::unswap(state_key, buf)
			};

			proffer(room_id);
			return ret;
		}};

		state.for_each("ircd.rooms", proffer_state);
		return ret;
	}

	return events::type::for_each_in("m.room.create", [&proffer, &ret]
	(const string_view &type, const event::idx &event_idx)
	{
		assert(type == "m.room.create");
		m::get(std::nothrow, event_idx, "room_id", proffer);
		return ret;
	});
}

//
// ircd::m::rooms::opts::opts
//

IRCD_MODULE_EXPORT
ircd::m::rooms::opts::opts(const string_view &input)
noexcept
:room_id
{
	valid(m::id::ROOM, input)?
		m::id::room{input}:
		m::id::room{}
}
,server
{
	startswith(input, ':')?
		lstrip(input, ':'):
		string_view{}
}
,room_alias
{
	valid(m::id::ROOM_ALIAS, input)?
		m::id::room_alias{input}:
		m::id::room_alias{}
}
,user_id
{
	valid(m::id::USER, input)?
		m::id::user{input}:
		m::id::user{}
}
,local_only
{
	has(input, "local_only")
}
,remote_only
{
	has(input, "remote_only")
}
,local_joined_only
{
	has(input, "local_joined_only")
}
,remote_joined_only
{
	has(input, "remote_joined_only")
}
,search_term
{
	!room_id && !server && !room_alias && !user_id
	&& !local_only && !remote_only
	&& !local_joined_only && !remote_joined_only?
		input:
		string_view{}
}
{
}