module FFaker
  module Avatar
    extend ModuleUtils
    extend self

    SUPPORTED_FORMATS = %w[png jpg bmp].freeze

    def image(slug = nil, size = '300x300', format = 'png', bgset = nil)
      check_passed_params(size, format, bgset)
      slug ||= FFaker::Lorem.words.join
      "https://robohash.org/#{slug}.#{format}?size=#{size}#{'&bgset=bg' + bgset.to_s if bgset}"
    end

    private

    def check_passed_params(size, format, bgset)
      invalid_size_error unless size =~ /^[0-9]+x[0-9]+$/
      invalid_format_error unless SUPPORTED_FORMATS.include?(format)
      invalid_background_number unless bgset.nil? || (1..2).cover?(bgset.to_i)
    end

    def invalid_size_error
      raise ArgumentError, 'Size should be specified in format 300x300'
    end

    def invalid_format_error
      raise ArgumentError, "Supported formats are #{SUPPORTED_FORMATS.join(', ')}"
    end

    def invalid_background_number
      raise ArgumentError, 'Not a supported background number. Choose eather 1 or 2'
    end
  end
end
