Epic Games - Ruby script to fetch free games from website

free_games.rb

require 'json'

require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'

  gem 'faraday'
end

DEFAULT_API_URL = 'https://store-site-backend-static.ak.epicgames.com/freeGamesPromotions?locale=pt-BR&country=BR&allowCountries=BR'
EPIC_GAMES_FREE_GAMES_API_URL = ENV['EPIC_GAMES_API_URL'] || DEFAULT_API_URL

class Game < Struct.new(:id, :title, :image, :slug, :started_at, :ended_at, keyword_init: true)
  def to_json
    {
      id: id,
      title: title,
      image: image,
      slug: slug,
      started_at: started_at,
      ended_at: ended_at,
    }
  end
end

response = Faraday.get(EPIC_GAMES_FREE_GAMES_API_URL)
raise RuntimeError.new("Error connecting to the Epic Games free-games API!") unless response.success?

payload = JSON.parse(response.body)

select_games = ->(payload) {
  payload.dig('data', 'Catalog', 'searchStore', 'elements')
}

select_image = ->(game_payload) {
  image = game_payload['keyImages'].find { |image| image['type'] == 'VaultClosed' }
  image ? image['url'] : nil
}

select_promotion_dates = ->(game_payload) {
  offers = game_payload['promotions']['promotionalOffers'].first
  offers ? offers['promotionalOffers'].first : { 'startDate' => nil, 'endDate' => nil }
}

select_promotion_started_date = ->(game_payload) {
  select_promotion_dates.(game_payload)['startDate']
}

select_promotion_end_date = ->(game_payload) {
  select_promotion_dates.(game_payload)['endDate']
}

games = select_games.(payload).map do |game|
  Game.new(
    id: game['id'],
    title: game['title'],
    image: select_image.(game),
    slug: game['urlSlug'],
    started_at: select_promotion_started_date.(game),
    ended_at: select_promotion_end_date.(game),
  )
end

pp games