class IO::Endpoint::Wrapper

def accept(server, timeout: nil, linger: nil, **options, &block)
	while true
		socket, address = server.accept
		
		if linger
			socket.setsockopt(SOL_SOCKET, SO_LINGER, 1)
		end
		
		if timeout
			set_timeout(socket, timeout)
		end
		
		async do
			yield socket, address
		end
	end
end

def async
	raise NotImplementedError
end

def bind(local_address, protocol: 0, reuse_address: true, reuse_port: nil, linger: nil, bound_timeout: nil, **options, &block)
	socket = nil
	
	begin
		socket = ServerSocket.new(local_address.afamily, local_address.socktype, protocol)
		
		if reuse_address
			socket.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
		end
		
		if reuse_port
			socket.setsockopt(SOL_SOCKET, SO_REUSEPORT, 1)
		end
		
		if linger
			socket.setsockopt(SOL_SOCKET, SO_LINGER, 1)
		end
		
		# Set the timeout:
		if bound_timeout
			set_timeout(socket, bound_timeout)
		end
		
		socket.bind(local_address.to_sockaddr)
	rescue
		socket&.close
		raise
	end
	
	return socket unless block_given?
	
	async do
		begin
			yield socket
		ensure
			socket.close
		end
	end
end

def connect(remote_address, local_address: nil, linger: nil, timeout: nil, buffered: false, **options)
	socket = nil
	
	begin
		socket = ::Socket.new(remote_address.afamily, remote_address.socktype, remote_address.protocol)
		
		if linger
			socket.setsockopt(SOL_SOCKET, SO_LINGER, 1)
		end
		
		if buffered == false
			set_buffered(socket, buffered)
		end
		
		if timeout
			set_timeout(socket, timeout)
		end
		
		if local_address
			if defined?(IP_BIND_ADDRESS_NO_PORT)
				# Inform the kernel (Linux 4.2+) to not reserve an ephemeral port when using bind(2) with a port number of 0. The port will later be automatically chosen at connect(2) time, in a way that allows sharing a source port as long as the 4-tuple is unique.
				socket.setsockopt(SOL_IP, IP_BIND_ADDRESS_NO_PORT, 1)
			end
			
			socket.bind(local_address.to_sockaddr)
		end
	rescue
		socket&.close
		raise
	end
	
	begin
		socket.connect(remote_address.to_sockaddr)
	rescue Exception
		socket.close
		raise
	end
	
	return socket unless block_given?
	
	begin
		yield socket
	ensure
		socket.close
	end
end

def set_buffered(socket, buffered)
	case buffered
	when true
		socket.setsockopt(IPPROTO_TCP, TCP_NODELAY, 0)
	when false
		socket.setsockopt(IPPROTO_TCP, TCP_NODELAY, 1)
	end
rescue Errno::EINVAL
	# On Darwin, sometimes occurs when the connection is not yet fully formed. Empirically, TCP_NODELAY is enabled despite this result.
rescue Errno::EOPNOTSUPP
	# Some platforms may simply not support the operation.
rescue Errno::ENOPROTOOPT
	# It may not be supported by the protocol (e.g. UDP). ¯\_(ツ)_/¯
end

def set_timeout(io, timeout)
	io.timeout = timeout
end

def set_timeout(io, timeout)
	warn "IO#timeout= not supported on this platform."
end