# frozen_string_literal: true

require 'httparty'

# Listas de bloqueo y sus URLs de descarga
class ActivityPub
  class Fediblock < ApplicationRecord
    class Client
      include ::HTTParty

      # @param url [String]
      # @return [HTTParty::Response]
      def get(url)
        self.class.get(url, parser: csv_parser)
      end

      # Procesa el CSV
      #
      # @return [Proc]
      def csv_parser
        @csv_parser ||=
          begin
            require 'csv'

            proc do |body, _|
              CSV.parse(body, headers: true)
            end
          end
      end
    end

    class FediblockDownloadError < ::StandardError; end

    validates_presence_of :title, :url, :download_url, :format
    validates_inclusion_of :format, in: %w[mastodon fediblock]

    HOSTNAME_HEADERS = {
      'mastodon'  => '#domain',
      'fediblock' => 'domain'
    }

    def client
      @client ||= Client.new
    end

    # Descarga la lista y crea las instancias con el estado necesario
    def process!
      response = client.get(download_url)

      raise FediblockDownloadError unless response.ok?

      Fediblock.transaction do
        csv = response.parsed_response
        process_csv! csv

        update(instances: csv.map { |r| r[hostname_header] })
      end
    end

    private

    def hostname_header
      HOSTNAME_HEADERS[format]
    end

    # Crea o encuentra instancias que ya existían y las bloquea
    #
    # @param csv [CSV::Table]
    def process_csv!(csv)
      csv.each do |row|
        ActivityPub::Instance.find_or_create_by(hostname: row[hostname_header]).tap do |i|
          i.block! if i.may_block?
        end
      end
    end
  end
end