# frozen_string_literal: true

module Facter
  module Resolvers
    class Mountpoints < BaseResolver
      include Facter::FilesystemHelper
      @fact_list ||= {}
      @log = Facter::Log.new(self)
      class << self
        private

        def post_resolve(fact_name)
          @fact_list.fetch(fact_name) { read_mounts }
        end

        def root_device
          cmdline = Util::FileHelper.safe_read('/proc/cmdline')
          match = cmdline.match(/root=([^\s]+)/)
          match&.captures&.first
        end

        def compute_device(device)
          # If the "root" device, lookup the actual device from the kernel options
          # This is done because not all systems symlink /dev/root
          device = root_device if device == '/dev/root'
          device
        end

        def read_mounts # rubocop:disable Metrics/AbcSize
          mounts = []
          FilesystemHelper.read_mountpoints.each do |fs|
            device = compute_device(fs.name)
            filesystem = fs.mount_type
            path = fs.mount_point
            options = fs.options.split(',').map(&:strip)

            next if path =~ %r{^/(proc|sys)} && filesystem != 'tmpfs' || filesystem == 'autofs'

            stats = FilesystemHelper.read_mountpoint_stats(path)
            size_bytes = stats.bytes_total.abs
            available_bytes = stats.bytes_available.abs

            used_bytes = stats.bytes_used.abs
            total_bytes = used_bytes + available_bytes
            capacity = FilesystemHelper.compute_capacity(used_bytes, total_bytes)

            size = Facter::FactsUtils::UnitConverter.bytes_to_human_readable(size_bytes)
            available = Facter::FactsUtils::UnitConverter.bytes_to_human_readable(available_bytes)
            used = Facter::FactsUtils::UnitConverter.bytes_to_human_readable(used_bytes)

            mounts << Hash[FilesystemHelper::MOUNT_KEYS.zip(FilesystemHelper::MOUNT_KEYS
              .map { |v| binding.local_variable_get(v) })]
          end
          @fact_list[:mountpoints] = mounts
        end
      end
    end
  end
end