# frozen_string_literal: true

class IMICFPS
  module Networking
    class Connection
      attr_reader :address, :port
      attr_accessor :total_packets_sent, :total_packets_received, :total_data_sent, :total_data_received, :last_read_time, :last_write_time

      def initialize(address:, port:)
        @address = address
        @port = port

        @read_buffer = ReadBuffer.new
        @packet_write_queue = []

        @peer_id = 0

        @last_read_time = Networking.milliseconds
        @last_write_time = Networking.milliseconds

        @total_packets_sent = 0
        @total_packets_received = 0
        @total_data_sent = 0
        @total_data_received = 0

        @socket = nil
      end

      def connect
        @socket = UDPSocket.new
        @socket.connect(@address, @port)

        send_packet(
          Packet.new(
            peer_id: 0,
            sequence: 0,
            type: Protocol::CONNECT,
            payload: "Hello World!"
          )
        )
      end

      def send_packet(packet)
        Packet.splinter(packet).each do |pkt|
          @packet_write_queue << pkt
        end
      end

      def update
        while read
        end

        write

        # puts "#{Networking.milliseconds} Total sent: #{@total_packets_sent} packets, #{@total_data_sent} data"
        # puts "#{Networking.milliseconds} Total received: #{@total_packets_received} packets, #{@total_data_received} data"
        @read_buffer.reconstruct_packets.each do |packet, _addr_info|
          @peer_id = packet.payload.unpack1("C") if packet.peer_id.zero? && packet.type == Protocol::VERIFY_CONNECT
        end

        if @peer_id.positive? && Networking.milliseconds - @last_read_time >= Protocol::HEARTBEAT_INTERVAL
          send_packet(Packet.new(peer_id: @peer_id, sequence: 0, type: Protocol::HEARTBEAT, payload: ""))
        end
      end

      def close
        @socket&.close
      end

      private

      def read
        data, addr = @socket.recvfrom_nonblock(Protocol::MAX_PACKET_SIZE)
        @read_buffer.add(data, addr)

        @total_packets_received += 1
        @total_data_received += data.length
        @last_read_time = Networking.milliseconds
        true
      rescue IO::WaitReadable
        false
      end

      def write
        while (packet = @packet_write_queue.shift)
          @socket.send(packet.encode, 0, @address, @port)

          @total_data_sent += packet.encode.length
          @total_packets_sent += 1
        end
      end
    end
  end
end