guronsan.cr

require "./guronsan/*"
require "json"
require "http"

module Guronsan
  module Command
    extend self

    def run(command, args = nil)
      io = String::Builder.new
      Process.run(command, args: args, shell: true, output: io)
      io.to_s
    end

    def lastlogin
      result = run("last | head -1 | awk '{print $1,$3,$4,$5,$6}'").split()
      username = result[0]
      datetime = result[1..-1].join(' ')
      dt = Time.parse(datetime, "%a %b %-d %R")
      dt = Time.new(Time.now.year, dt.month, dt.day, dt.hour, dt.minute)
      { username, dt }
    end

    def send(body)
      client = HTTP::Client.new("127.0.0.1", 8081)
      headers = HTTP::Headers.new

      headers.add("User-Agent", "Guronsan")
      headers.add("Content-Type", "application/json")

      client.post("/", headers, body.to_json) do |response|
        puts response.status_code
      end
    end
  end

  module Message
    struct Payload(T)
      def initialize(@command : String, @payload : T)
      end

      JSON.mapping({
        command: String,
        payload: { type: T }
      })
    end

    struct LastLogin
      def initialize(@username : String, @datetime : Time)
      end

      JSON.mapping({
        username: String,
        datetime: { type: Time, converter: Time::EpochConverter }
      })
    end
  end

  username, datetime = Command.lastlogin

  lastlogin = Message::LastLogin.new(username, datetime)
  payload = Message::Payload.new("lastlogin", lastlogin)

  # output
  puts payload.to_json

  # consume
  puts Message::Payload(Message::LastLogin).from_json(payload.to_json)
end