#!/usr/bin/env ruby

begin
  require 'rubygems'
rescue LoadError
end
require 'ohai/system'
require 'json'
require 'httpclient'
require 'logger'
require 'optparse'

module NodeAgentConfig
  extend self
  
  attr_accessor :api

  def define
    yield self
  end
end


class NodeAgent
  def initialize(logger, config=nil)
    @logger = logger

    @api_default_address = "localhost"
    @api_default_port = "8000"

    if not config.nil?
      if not config.api.nil?
        @api_url = config.api
      end
    end

    if not @api_url
      begin
        cmdline = ::File.read("/proc/cmdline")
        api_ip = cmdline.match(/\burl=http:\/\/((\d{1,3}\.){3}\d{1,3})/)[1]
        @logger.info("Found admin node IP address in kernel cmdline: #{api_ip}")
      rescue
        @logger.error("Can't get API url from /proc/cmdline. Will use localhost.")
        api_ip = "127.0.0.1"
      end
      @api_url = "http://#{api_ip}:#{@api_default_port}/api"
    end

    @os = Ohai::System.new()
    @os.all_plugins
  end

  def put
    headers = {"Content-Type" => "application/json"}
    htclient = HTTPClient.new
    @logger.debug("Trying to put host info into #{@api_url}")
    res = htclient.put("#{@api_url}/nodes/", [_data].to_json, headers)
    if res.status < 200 or res.status >= 300
      @logger.error("HTTP PUT failed: #{res.inspect}")
    end
    return res
  end

  def post
    headers = {"Content-Type" => "application/json"}
    htclient = HTTPClient.new
    @logger.debug("Trying to create host using #{@api_url}")
    res = htclient.post("#{@api_url}/nodes/", _data.to_json, headers)
    return res
  end

  def _interfaces 
    interfaces = @os[:network][:interfaces].inject([]) do |result, elm|
      result << { :name => elm[0], :addresses => elm[1]["addresses"] }
    end
    interfaces << { "default_interface" => @os["network"]["default_interface"] }
    interfaces << { "default_gateway" => @os["network"]["default_gateway"] }
    interfaces
  end

  def _mac
    @os[:macaddress]
  end

  def _metadata
    {
      :block_device => @os["block_device"].to_hash,
      :interfaces => _interfaces,
      :cpu => @os["cpu"].to_hash,
      :memory => @os["memory"].to_hash,
      :serial => _serial
    }
  end

  def _is_virtual
    begin
      if @os["virtualization"]["role"] == "guest"
        return true
      end
    rescue
    end
    return false
  end

  def _manufacturer
    if _is_virtual
      return @os["virtualization"]["system"].upcase
    else
      begin
        return @os[:dmi][:system][:manufacturer]
      rescue
        return "Unknown"
      end
    end
  end

  def _product_name
    if _is_virtual
      return @os["virtualization"]["role"]
    else
      begin
        return @os[:dmi][:system][:product_name]
      rescue
        return "Unknown"
      end
    end
  end

  def _serial
    begin
      return @os[:dmi][:system][:serial_number]
    rescue
      return "Unknown"
    end
  end

  def _data
    res = { 
      :fqdn => @os[:fqdn],
      :mac => @os[:macaddress],
      :ip  => @os[:ipaddress],
      :manufacturer => _manufacturer,
      :platform_name => _product_name,
      :os_platform => @os[:platform],
      :meta => _metadata
    }
    
    res[:status] = @node_state if @node_state
    res
  end

  def update_state
    @node_state = nil
    if File.exist?("/opt/nailgun/system_type")
      fl = File.open("/opt/nailgun/system_type", "r")
      system_type = fl.readline.rstrip
      @node_state = "discover" if system_type == "bootstrap"
    else
      fl = File.open("/opt/nailgun/system_type", "w")
      fl.puts("target")
      @node_state = "ready"
    end
  end

end


logger = Logger.new(STDOUT)
logger.level = Logger::DEBUG


options = {}
optparser = OptionParser.new do |opts|
  opts.banner = "Usage: #{__FILE__} [options]"

  opts.on( '-h', '--help', 'Display this screen' ) do
    puts opts
    exit
  end

  opts.on("-c", "--config CONFIG", "Config file") do |config_file|
    options[:config_file] = config_file
  end

end

optparser.parse!

if options[:config_file].nil?
  options[:config_file] = "/etc/nailgun-agent/config.rb"
end

begin
  logger.info("Trying to load agent config #{options[:config_file]}")
  load options[:config_file]
rescue LoadError
  logger.error("Error occured while loading agent config")
end


agent = NodeAgent.new(logger, NodeAgentConfig)
begin
  agent.update_state
  res = agent.post
  if res.status == 409:
    agent.put
  end
rescue Exception => e
  logger.error("Error in sending node info: #{e.message}")
end