class MavisCLI::LocalAuthorities::ImportPostcodeMappings

# File app/lib/mavis_cli/local_authorities/import_postcode_mappings.rb, line 13
def call(input_file: nil, **)
  MavisCLI.load_rails
  import_file(input_file)
end

# File app/lib/mavis_cli/local_authorities/import_postcode_mappings.rb, line 18
def import_file(input_file)
  postcode_field = "pcds"
  gss_code_field = "ladcd"
  objects_to_import = []
  batch_size = 1000

  Zip::File.open(input_file) do |zip|
    csv_entry = zip.glob("*.csv").first
    puts "importing postcode/gss code mappings from #{input_file}"
    csv_entry.get_input_stream do |stream|
      headers = stream.gets.split(",")
      postcode_index = headers.index(postcode_field)
      gss_code_index = headers.index(gss_code_field)

      # rubocop:disable Rails/SaveBang
      progress_bar =
        ProgressBar.create(
          starting_at: 0,
          total: stream.size,
          format: "%a %e %P% Processed: %c bytes of %C"
        )
      # rubocop:enable Rails/SaveBang

      line_no = 1
      LocalAuthority::Postcode.transaction do
        puts "deleting #{LocalAuthority::Postcode.count} existing LocalAuthority::Postcode mappings"
        LocalAuthority::Postcode.delete_all

        stream.each_line do |line|
          # puts "parsing line #{line_no}"
          data = CSV.parse_line(line)
          postcode = data[postcode_index]
          gss_code = data[gss_code_index]

          objects_to_import << LocalAuthority::Postcode.new(
            gss_code: gss_code,
            value: postcode
          )
          line_no += 1
          progress_bar.progress = stream.pos
          next unless (objects_to_import.size % batch_size).zero?
          # puts "importing #{objects_to_import.size} objects"
          LocalAuthority::Postcode.import!(objects_to_import)
          objects_to_import.clear
        end
      end
    end
  end
end