class Holiday

# File lib/holiday.rb, line 13
def initialize(calendars)
  @calendars = calendars
end

# File lib/holiday.rb, line 17
def in(year)
  holidays[year]
end

# File lib/holiday.rb, line 21
def load_data
  # TODO: remove this in a major version
  holidays
  calendars
end

# File lib/holiday.rb, line 34
def by_year(holidays_by_year, date)
  holidays_by_year ||= {}
  holidays_by_year[date.year] ||= []
  holidays_by_year[date.year] << date
  holidays_by_year
end

# File lib/holiday.rb, line 45
def holiday_file(calendar)
  filename = holiday_filename(calendar)

  return if filename.nil?

  path = File.dirname(__FILE__) + "/../data/#{filename}"
  JSON.parse(File.read(File.expand_path(path)))
end

# File lib/holiday.rb, line 54
def holiday_filename(calendar)
  holiday_files.select do |_filename, calendar_names|
    calendar_names.include?(calendar)
  end.keys.first
end

# File lib/holiday.rb, line 60
def holiday_files
  @holiday_files ||= JSON.parse(File.read(CALENDARS_FILENAME))
  @holiday_files
end

# File lib/holiday.rb, line 29
def holidays
  @holidays ||= calendars.flat_map(&method(:to_holidays)).uniq.
                reduce({}, &method(:by_year))
end

# File lib/holiday.rb, line 41
def to_holidays(calendar)
  holiday_file(calendar).map(&:to_date)
end