# frozen_string_literal: true

# This will check microsoft security portal for the kbs assosicated with an operating system for a given CVE.
#
# end goal usage: <script.rb> --cve CVE-2020-1234 --os "Windows Server 2012 R2"
#
require 'json'
require 'rest-client'
require 'pry'

class MicrosoftKbChecker
  attr_accessor :options

  # options hash {:cve_id => 'cve-2020-1234', :os_name => 'Windows Server 2012'}
  def initialize(options)
    @options = options
  end

  AVAILABLE_OS = [
    'Windows 10 Version 2004 for 32-bit Systems',
    'Windows 10 Version 2004 for ARM64-based Systems',
    'Windows 10 Version 2004 for x64-based Systems',
    'Windows Server, version 2004 (Server Core installation)',
    'Windows 10 Version 1803 for 32-bit Systems',
    'Windows 10 Version 1803 for x64-based Systems',
    'Windows 10 Version 1803 for ARM64-based Systems',
    'Windows 10 Version 1809 for 32-bit Systems',
    'Windows 10 Version 1809 for x64-based Systems',
    'Windows 10 Version 1809 for ARM64-based Systems',
    'Windows Server 2019',
    'Windows Server 2019  (Server Core installation)',
    'Windows 10 Version 1909 for 32-bit Systems',
    'Windows 10 Version 1909 for x64-based Systems',
    'Windows 10 Version 1909 for ARM64-based Systems',
    'Windows Server, version 1909 (Server Core installation)',
    'Windows 10 Version 1709 for 32-bit Systems',
    'Windows 10 Version 1709 for x64-based Systems',
    'Windows 10 Version 1709 for ARM64-based Systems',
    'Windows 10 Version 1903 for 32-bit Systems',
    'Windows 10 Version 1903 for x64-based Systems',
    'Windows 10 Version 1903 for ARM64-based Systems',
    'Windows Server, version 1903 (Server Core installation)',
    'Windows 10 for 32-bit Systems',
    'Windows 10 for x64-based Systems',
    'Windows 10 Version 1607 for 32-bit Systems',
    'Windows 10 Version 1607 for x64-based Systems',
    'Windows Server 2016',
    'Windows Server 2016  (Server Core installation)',
    'Windows 7 for 32-bit Systems Service Pack 1',
    'Windows 7 for x64-based Systems Service Pack 1',
    'Windows 8.1 for 32-bit systems',
    'Windows 8.1 for x64-based systems',
    'Windows RT 8.1',
    'Windows Server 2008 for 32-bit Systems Service Pack 2',
    'Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)',
    'Windows Server 2008 for x64-based Systems Service Pack 2',
    'Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)',
    'Windows Server 2008 R2 for x64-based Systems Service Pack 1',
    'Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)',
    'Windows Server 2012',
    'Windows Server 2012 (Server Core installation)',
    'Windows Server 2012 R2',
    'Windows Server 2012 R2 (Server Core installation)'
  ].freeze

  def cve_url
    cve = options[:cve_id]
    "https://portal.msrc.microsoft.com/api/security-guidance/en-US/CVE/#{cve}"
  end

  def make_request
    RestClient::Request.execute(
      method: :get,
      headers: { Host: 'portal.msrc.microsoft.com' },
      url: cve_url
    )
  end

  def parse_json(response)
    JSON.parse(response)
  end

  def os_available?
    AVAILABLE_OS.include?(options[:os_name])
  end

  def query_cve
    if os_available?
      response = make_request
      json = parse_json(response)
      os_results = select_os(json)
      kbs_for_os(os_results) if os_results
    else
      'Operating system not found.'
    end
  end

  def select_os(json)
    json.dig('affectedProducts').select do |os|
      os['name'] == options[:os_name]
    end.first
  end

  def kbs_for_os(os_json)
    supersedence = os_json.values_at('supersedence')
    articles = article_title_keys(os_json)
    kbs = articles.map do |article_info|
      num = article_info[:article_num]
      os_json.values_at("articleTitle#{num}")
    end
    {
      os_name: os_json['name'],
      kbs: kbs,
      supersedence_kb: supersedence
    }
  end

  def article_title_keys(json)
    # let us know if we have a kb article in our json response data
    # the json response is made up of 4 articleTitle keys
    # i have this looping through 99 in case there are more articles from the ones ive manually looked at
    results = (1..99).map { |index| { article_num: index, has_key?: json.key?("articleTitle#{index}") } }
    results.select { |r| r if r[:has_key?] == true }
  end
end