# frozen_string_literal: true

module Facter
  module Resolvers
    class NetworkingLinux < BaseResolver
      @semaphore = Mutex.new

      class << self
        private

        def post_resolve(fact_name)
          retrieve_network_info(fact_name) if @fact_list.nil?

          @fact_list[fact_name]
        end

        def retrieve_network_info(fact_name)
          @fact_list ||= {}

          retrieve_default_interface_and_ip
          retrieve_interface_info
          retrieve_macaddress
          @fact_list[fact_name]
        end

        def retrieve_macaddress
          output, _status = Open3.capture2("ip link show #{@fact_list[:primary_interface]}")
          macaddress = */ether ([^ ]*) /.match(output)
          @fact_list[:macaddress] = macaddress[1]
        end

        def retrieve_interface_info
          output, _status = Open3.capture2('ip -o address')
          interfaces = {}

          output.each_line do |ip_line|
            ip_tokens = ip_line.split(' ')

            fill_ip_v4_info!(ip_tokens, interfaces)
            fill_io_v6_info!(ip_tokens, interfaces)
          end

          @fact_list[:interfaces] = interfaces
        end

        def fill_ip_v4_info!(ip_tokens, network_info)
          return unless ip_tokens[2].casecmp('inet').zero?

          interface_name = ip_tokens[1]
          ip4_info = ip_tokens[3].split('/')
          ip4_address = ip4_info[0]
          ip4_mask_length = ip4_info[1]

          binding = build_binding(ip4_address, ip4_mask_length)
          build_network_info_structure!(network_info, interface_name, 'bindings')

          network_info[interface_name]['bindings'] << binding
        end

        def fill_io_v6_info!(ip_tokens, network_info)
          return unless ip_tokens[2].casecmp('inet6').zero?

          interface_name = ip_tokens[1]
          ip6_info = ip_tokens[3].split('/')
          ip6_address = ip6_info[0]
          ip6_mask_length = ip6_info[1]

          binding = build_binding(ip6_address, ip6_mask_length)

          build_network_info_structure!(network_info, interface_name, 'bindings6')

          network_info[interface_name]['bindings6'] << binding
        end

        def retrieve_default_interface_and_ip
          output, _status = Open3.capture2('ip route get 1')

          ip_route_tokens = output.each_line.first.strip.split(' ')
          default_interface = ip_route_tokens[4]
          default_ip = ip_route_tokens[6]

          @fact_list[:ip] = default_ip
          @fact_list[:primary_interface] = default_interface
        end

        def build_binding(addr, mask_length)
          require 'ipaddr'

          ip = IPAddr.new(addr)
          mask_helper = ip.ipv6? ? 'ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff' : '255.255.255.255'
          mask = IPAddr.new(mask_helper).mask(mask_length)

          { address: addr, netmask: mask.to_s, network: ip.mask(mask_length).to_s }
        end

        def build_network_info_structure!(network_info, interface_name, binding)
          network_info[interface_name] = {} unless network_info.dig(interface_name)
          network_info[interface_name][binding] = [] unless network_info.dig(interface_name, binding)
        end
      end
    end
  end
end