class Async::IO::Socket

def self.accept(*args, backlog: SOMAXCONN, &block)
	bind(*args) do |server, task|
		server.listen(backlog) if backlog
		
		server.accept_each(task: task, &block)
	end
end

def self.bind(local_address, protocol: 0, reuse_port: false, task: Task.current, **options, &block)
	wrapper = build(local_address.afamily, local_address.socktype, protocol, **options) do |socket|
		socket.setsockopt(::Socket::SOL_SOCKET, ::Socket::SO_REUSEADDR, true)
		socket.setsockopt(::Socket::SOL_SOCKET, ::Socket::SO_REUSEPORT, true) if reuse_port
		socket.bind(local_address.to_sockaddr)
	end
	
	return wrapper unless block_given?
	
	task.async do
		task.annotate "binding to #{local_address.inspect}"
		
		begin
			yield wrapper, task
		ensure
			wrapper.close
		end
	end
end

def self.build(*args, task: Task.current)
	socket = wrapped_klass.new(*args)
	
	yield socket
	
	return self.new(socket, task.reactor)
rescue Exception
	socket.close if socket
	
	raise
end

def self.connect(remote_address, local_address = nil, reuse_port: false, task: Task.current, **options)
	task.annotate "connecting to #{remote_address.inspect}"
	
	wrapper = build(remote_address.afamily, remote_address.socktype, remote_address.protocol, **options) do |socket|
		socket.setsockopt(::Socket::SOL_SOCKET, ::Socket::SO_REUSEADDR, reuse_port)
		
		if local_address
			socket.bind(local_address.to_sockaddr)
		end
		self.new(socket, task.reactor)
	end
	
	begin
		wrapper.connect(remote_address.to_sockaddr)
		task.annotate "connected to #{remote_address.inspect}"
	rescue
		wrapper.close
		raise
	end
	
	return wrapper unless block_given?
	
	begin
		yield wrapper, task
	ensure
		wrapper.close
	end
end

def self.pair(*args)
	::Socket.pair(*args).map(&self.method(:new))
end

def accept(task: Task.current)
	peer, address = async_send(:accept_nonblock)
	wrapper = Socket.new(peer, task.reactor)
	
	return wrapper, address unless block_given?
	
	task.async do |task|
		task.annotate "incoming connection #{address.inspect}"
		
		begin
			yield wrapper, address
		ensure
			wrapper.close
		end
	end
end

def connect(*args)
	begin
		async_send(:connect_nonblock, *args)
	rescue Errno::EISCONN
		# We are now connected.
	end
end