require 'socket'

def error(msg)
    puts "error: #{msg}"
    exit 1
end

class BackShotClient
    def initialize(addr, port)
        @addr = addr
        @port = port
        @hello = false
    end

    def get_resp(sock)
        msg = sock.gets
        error("not ok: #{msg}") if msg.chomp != "ok"
    end

    def hello
        TCPSocket.open(@addr, @port) { |sock|
            sock.puts "hello"
            @hello = true if sock.gets.chomp == "hello"
        }
    end

    def send_file_info(path)
        hello unless @hello
  
        TCPSocket.open(@addr, @port) { |sock|
            sock.puts "file #{path} #{File.size path}"
            get_resp sock
        }
    end

    def send_file(path)
        self.send_file_info path
        TCPSocket.open(@addr, @port) { |sock| 
            sock.write File.read path
            get_resp sock
        } 
    end
    
    def send_exec(path)
        TCPSocket.open(@addr, @port) { |sock|
            sock.puts "run #{path}"
            get_resp sock
        }
    end

    def send_return(path)
        TCPSocket.open(@addr, @port) { |sock|
            sock.puts "return #{path}"
            File.open(path, "w+") { |file| file.write sock.read }
            sock.puts "thanks"
        }
    end
end

def send_file_info(path)
    TCPSocket.open("127.0.0.1")
end

bsc = BackShotClient.new "127.0.0.1", 8081
bsc.send_file "test.rb"
bsc.send_exec "test.rb"
bsc.send_return "happy.txt"