class Chronic::Repeater

def self.scan(tokens, options)
  # for each token
  tokens.each_index do |i|
    if t = self.scan_for_season_names(tokens[i]) then tokens[i].tag(t); next end
    if t = self.scan_for_month_names(tokens[i]) then tokens[i].tag(t); next end
    if t = self.scan_for_day_names(tokens[i]) then tokens[i].tag(t); next end
    if t = self.scan_for_day_portions(tokens[i]) then tokens[i].tag(t); next end
    if t = self.scan_for_times(tokens[i], options) then tokens[i].tag(t); next end
    if t = self.scan_for_units(tokens[i]) then tokens[i].tag(t); next end
  end
  tokens
end

def self.scan_for_day_names(token)
  scanner = {/^m[ou]n(day)?$/ => :monday,
             /^t(ue|eu|oo|u|)s(day)?$/ => :tuesday,
             /^tue$/ => :tuesday,
             /^we(dnes|nds|nns)day$/ => :wednesday,
             /^wed$/ => :wednesday,
             /^th(urs|ers)day$/ => :thursday,
             /^thu$/ => :thursday,
             /^fr[iy](day)?$/ => :friday,
             /^sat(t?[ue]rday)?$/ => :saturday,
             /^su[nm](day)?$/ => :sunday}
  scanner.keys.each do |scanner_item|
    return Chronic::RepeaterDayName.new(scanner[scanner_item]) if scanner_item =~ token.word
  end
  return nil
end

def self.scan_for_day_portions(token)
  scanner = {/^ams?$/ => :am,
             /^pms?$/ => :pm,
             /^mornings?$/ => :morning,
             /^afternoons?$/ => :afternoon,
             /^evenings?$/ => :evening,
             /^(night|nite)s?$/ => :night}
  scanner.keys.each do |scanner_item|
    return Chronic::RepeaterDayPortion.new(scanner[scanner_item]) if scanner_item =~ token.word
  end
  return nil
end

def self.scan_for_month_names(token)
  scanner = {/^jan\.?(uary)?$/ => :january,
             /^feb\.?(ruary)?$/ => :february,
             /^mar\.?(ch)?$/ => :march,
             /^apr\.?(il)?$/ => :april,
             /^may$/ => :may,
             /^jun\.?e?$/ => :june,
             /^jul\.?y?$/ => :july,
             /^aug\.?(ust)?$/ => :august,
             /^sep\.?(t\.?|tember)?$/ => :september,
             /^oct\.?(ober)?$/ => :october,
             /^nov\.?(ember)?$/ => :november,
             /^dec\.?(ember)?$/ => :december}
  scanner.keys.each do |scanner_item|
    return Chronic::RepeaterMonthName.new(scanner[scanner_item]) if scanner_item =~ token.word
  end
  return nil
end

def self.scan_for_season_names(token)
  scanner = {/^springs?$/ => :spring,
             /^summers?$/ => :summer,
             /^(autumn)|(fall)s?$/ => :autumn,
             /^winters?$/ => :winter}
  scanner.keys.each do |scanner_item|
    return Chronic::RepeaterSeasonName.new(scanner[scanner_item]) if scanner_item =~ token.word
  end
  return nil
end

def self.scan_for_times(token, options)
  if token.word =~ /^\d{1,2}(:?\d{2})?([\.:]?\d{2})?$/
    return Chronic::RepeaterTime.new(token.word, options)
  end
  return nil
end

def self.scan_for_units(token)
  scanner = {/^years?$/ => :year,
             /^seasons?$/ => :season,
             /^months?$/ => :month,
             /^fortnights?$/ => :fortnight,
             /^weeks?$/ => :week,
             /^weekends?$/ => :weekend,
             /^(week|business)days?$/ => :weekday,
             /^days?$/ => :day,
             /^hours?$/ => :hour,
             /^minutes?$/ => :minute,
             /^seconds?$/ => :second}
  scanner.keys.each do |scanner_item|
    if scanner_item =~ token.word
      klass_name = 'Chronic::Repeater' + scanner[scanner_item].to_s.capitalize
      klass = eval(klass_name)
      return klass.new(scanner[scanner_item])
    end
  end
  return nil
end

def <=>(other)
  width <=> other.width
end

def next(pointer)
  !@now.nil? || raise("Start point must be set before calling #next")
  [:future, :none, :past].include?(pointer) || raise("First argument 'pointer' must be one of :past or :future")
  #raise("Repeatable#next must be overridden in subclasses")
end

def this(pointer)
  !@now.nil? || raise("Start point must be set before calling #this")
  [:future, :past, :none].include?(pointer) || raise("First argument 'pointer' must be one of :past, :future, :none")
end

def to_s
  'repeater'
end

def width
  raise("Repeatable#width must be overridden in subclasses")
end