require "ipc"

# TODO: Write documentation for `IPCd`
module IPCd
	VERSION = "0.1.0"

	def self.start
		ipcd = IPC.new()
		ipcd.service_init "hello"
		ipcd.timer 10_000
		ipcd.loop do |event|
			begin
				case event.type
				when LibIPC::EventType::Timer
					puts "Timer."

				when LibIPC::EventType::Connection
					fd = ipcd.connect "pong"
					ipcd.add_switch event.newfd, fd
					input  = -> fn_input( LibC::Int, LibC::Char*, LibC::UInt64T*)
					output = -> fn_output(LibC::Int, LibC::Char*, LibC::UInt64T )
					ipcd.switch_callbacks event.newfd, input, output
					puts "New connection (#{event.newfd}) now automatically switched to 'pong' (#{fd})!"

				when LibIPC::EventType::Disconnection
					puts "Disconnection from #{event.fd}."

				when LibIPC::EventType::MessageTx
					puts "Message sent to #{event.fd}."

				when LibIPC::EventType::MessageRx
					puts "Message received from #{event.fd}."

				when LibIPC::EventType::SwitchRx
					puts "Switch message received from #{event.fd}."

				when LibIPC::EventType::SwitchTx
					puts "Switch message sent to #{event.fd}."

				when LibIPC::EventType::Error
					puts "And error occured on fd #{event.fd}."

				else
					puts "Unhandled IPC event: #{event.class}."
					if event.responds_to?(:fd)
						puts "closing #{event.fd}"
						ipcd.close event.fd
					end
				end

			rescue exception
				puts "exception: #{typeof(exception)} - #{exception.message}"
			end
		end
	end
end

def fn_input(fd : LibC::Int, buffer : LibC::Char*, buflen : LibC::UInt64T*) : LibC::Char
	puts "switch input: #{fd}"
	io = IO::FileDescriptor.new fd, close_on_finalize: false
	slice = Bytes.new buffer, buflen.value
	len = io.read slice
	buflen.value = len.to_u64
	return 2_u8 if (len == 0)
	0_u8
rescue e
	puts "fn_input exception! #{e}"
	1_u8
end

def fn_output(fd : LibC::Int, buffer : LibC::Char*, buflen : LibC::UInt64T)  : LibC::Char
	puts "switch output: #{fd}"
	slice = Bytes.new buffer, buflen
	io = IO::FileDescriptor.new fd, close_on_finalize: false
	io.write slice
	io.flush
	0_u8
rescue e
	puts "fn_output exception! #{e}"
	1_u8
end

IPCd.start