# frozen_string_literal: true

# system.rb -- InSpec resources for system values
# Author: Daniel Dehennin <daniel.dehennin@ac-dijon.fr>
# Copyright (C) 2020 Daniel Dehennin <daniel.dehennin@ac-dijon.fr>

HOSTNAME_CMDS = %w[hostname hostnamectl].freeze
HOSTNAME_CMDS_OPT = {
  'hostname' => '-s',
  'hostnamectl' => '--static'
}.freeze

class SystemResource < Inspec.resource(1)
  name 'system'

  attr_reader :platform
  attr_reader :hostname

  def initialize
    @platform = build_platform
    @hostname = found_hostname
  end

  private

  def found_hostname
    cmd = guess_hostname_cmd

    unless cmd.exit_status.zero?
      raise Inspec::Exceptions::ResourceSkipped,
            "Error running '#{cmd}': #{cmd.stderr}"
    end

    cmd.stdout.chomp
  end

  def guess_hostname_cmd
    HOSTNAME_CMDS.each do |cmd|
      if inspec.command(cmd).exist?
        return inspec.command("#{cmd} #{HOSTNAME_CMDS_OPT[cmd]}")
      end
    end

    raise Inspec::Exceptions::ResourceSkipped,
          "Error: #{@platform[:finger]}} has none of #{HOSTNAME_CMDS.join(', ')}"
  end

  def build_platform
    {
      family: build_platform_family,
      name: build_platform_name,
      release: build_platform_release,
      finger: build_platform_finger
    }
  end

  def build_platform_family
    case inspec.platform[:name]
    when 'arch'
      'arch'
    else
      inspec.platform[:family]
    end
  end

  def build_platform_name
    case inspec.platform[:name]
    when 'amazon'
      'amazonlinux'
    else
      inspec.platform[:name]
    end
  end

  def build_platform_release
    case inspec.platform[:name]
    when 'amazon'
      # `2018` relase is named `1` in kitchen.yaml
      inspec.platform[:release].gsub(/2018.*/, '1')
    when 'arch'
      'base-latest'
    else
      inspec.platform[:release]
    end
  end

  def build_platform_finger
    "#{build_platform_name}-#{build_finger_release}"
  end

  def build_finger_release
    case inspec.platform[:name]
    when 'ubuntu'
      build_platform_release.split('.').slice(0, 2).join('.')
    else
      build_platform_release.split('.')[0]
    end
  end
end