# frozen_string_literal: true

require "csv"
require "net/http"

require "provider/adapters/adapter"

class Provider
  module Adapters
    class RBA < Adapter
      CSV_URL = "https://www.rba.gov.au/statistics/tables/csv/f11.1-data.csv"
      METADATA_ROWS = 11

      class << self
      end

      def fetch(after: nil, upto: nil)
        csv = Net::HTTP.get(URI(CSV_URL))
        dataset = parse(csv)
        dataset = dataset.select { |r| r[:date] >= after } if after
        dataset
      end

      def parse(csv)
        lines = csv.encode("UTF-8", invalid: :replace, undef: :replace).lines
        units_line = lines.find { |l| l.start_with?("Units,") }
        return [] unless units_line

        currencies = CSV.parse_line(units_line)
        currencies.shift # remove "Units" label

        data_lines = lines.drop(METADATA_ROWS)

        data_lines.flat_map do |line|
          row = CSV.parse_line(line)
          next unless row&.first&.match?(/\A\d{2}-[A-Za-z]{3}-\d{4}\z/)

          date = Date.parse(row.shift)

          row.zip(currencies).filter_map do |value, iso|
            next if iso.nil? || iso == "Index"
            next if value.nil? || value.strip.empty?

            rate = Float(value)
            { date:, base: "AUD", quote: iso, rate: }
          end
        end.compact
      end
    end
  end
end