class Chronic::RepeaterSeason

def construct_season(start, finish)
  Span.new(
    Time.construct(start.year, start.month, start.day),
    Time.construct(finish.year, finish.month, finish.day)
  )
end

def find_current_season(md)
  [:spring, :summer, :autumn, :winter].find do |season|
    md.is_between?(SEASONS[season].start, SEASONS[season].end)
  end
end

def find_next_season_span(direction, next_season)
  if !@next_season_start or !@next_season_end
    @next_season_start = Time.construct(@now.year, @now.month, @now.day)
    @next_season_end = Time.construct(@now.year, @now.month, @now.day)
  end
  @next_season_start += direction * num_seconds_til_start(next_season, direction)
  @next_season_end += direction * num_seconds_til_end(next_season, direction)
  construct_season(@next_season_start, @next_season_end)
end

def initialize(type)
  super
  @next_season_start = nil
end

def next(pointer)
  super
  direction = pointer == :future ? 1 : -1
  next_season = Season.find_next_season(find_current_season(@now.to_minidate), direction)
  find_next_season_span(direction, next_season)
end

def num_seconds_til(goal, direction)
  start = Time.construct(@now.year, @now.month, @now.day)
  seconds = 0
  until (start + direction * seconds).to_minidate.equals?(goal)
    seconds += RepeaterDay::DAY_SECONDS
  end
  seconds
end

def num_seconds_til_end(season_symbol, direction)
  num_seconds_til(SEASONS[season_symbol].end, direction)
end

def num_seconds_til_start(season_symbol, direction)
  num_seconds_til(SEASONS[season_symbol].start, direction)
end

def offset(span, amount, pointer)
  Span.new(offset_by(span.begin, amount, pointer), offset_by(span.end, amount, pointer))
end

def offset_by(time, amount, pointer)
  direction = pointer == :future ? 1 : -1
  time + amount * direction * SEASON_SECONDS
end

def this(pointer = :future)
  super
  direction = pointer == :future ? 1 : -1
  today = Time.construct(@now.year, @now.month, @now.day)
  this_ssn = find_current_season(@now.to_minidate)
  case pointer
  when :past
    this_ssn_start = today + direction * num_seconds_til_start(this_ssn, direction)
    this_ssn_end = today
  when :future
    this_ssn_start = today + RepeaterDay::DAY_SECONDS
    this_ssn_end = today + direction * num_seconds_til_end(this_ssn, direction)
  when :none
    this_ssn_start = today + direction * num_seconds_til_start(this_ssn, direction)
    this_ssn_end = today + direction * num_seconds_til_end(this_ssn, direction)
  end
  construct_season(this_ssn_start, this_ssn_end)
end

def to_s
  super << '-season'
end

def width
  SEASON_SECONDS
end