class Rufus::CronLine

def self.monthday(date)
  count = 1
  date2 = date.dup
  loop do
    date2 = date2 - DAY_IN_SECONDS
    break if date2.month != date.month
    count = count + 1
  end
  "#{WEEKDAYS[date.wday]}##{count}"
end

def date_match?(date)
  return false unless sub_match?(date.day, @days)
  return false unless sub_match?(date.month, @months)
  return false unless sub_match?(date.wday, @weekdays)
  return false unless sub_match?(CronLine.monthday(date), @monthdays)
  true
end

def initialize(line)
  super()
  @original = line
  items = line.split
  @timezone = (TZInfo::Timezone.get(items.last) rescue nil)
  items.pop if @timezone
  raise ArgumentError.new(
    "not a valid cronline : '#{line}'"
  ) unless items.length == 5 or items.length == 6
  offset = items.length - 5
  @seconds = offset == 1 ? parse_item(items[0], 0, 59) : [ 0 ]
  @minutes = parse_item(items[0 + offset], 0, 59)
  @hours = parse_item(items[1 + offset], 0, 24)
  @days = parse_item(items[2 + offset], 1, 31)
  @months = parse_item(items[3 + offset], 1, 12)
  @weekdays, @monthdays = parse_weekdays(items[4 + offset])
end

def matches?(time)
  time = Time.at(time) unless time.kind_of?(Time)
  time = @timezone.utc_to_local(time.getutc) if @timezone
  return false unless sub_match?(time.sec, @seconds)
  return false unless sub_match?(time.min, @minutes)
  return false unless sub_match?(time.hour, @hours)
  return false unless date_match?(time)
  true
end

def monthday_match(monthday, monthdays)
  return true if monthdays == nil
  return true if monthdays.include?(monthday)
end

def next_time(now=Time.now)
  time = @timezone ? @timezone.utc_to_local(now.getutc) : now
  time = time - time.usec * 1e-6 + 1
    # little adjustment before starting
  loop do
    unless date_match?(time)
      time += (24 - time.hour) * 3600 - time.min * 60 - time.sec
      next
    end
    unless sub_match?(time.hour, @hours)
      time += (60 - time.min) * 60 - time.sec
      next
    end
    unless sub_match?(time.min, @minutes)
      time += 60 - time.sec
      next
    end
    unless sub_match?(time.sec, @seconds)
      time += 1
      next
    end
    break
  end
  if @timezone
    time = @timezone.local_to_utc(time)
    time = time.getlocal unless now.utc?
  end
  time
end

def parse_item(item, min, max)
  return nil if item == '*'
  return parse_list(item, min, max) if item.index(',')
  return parse_range(item, min, max) if item.index('*') or item.index('-')
  i = item.to_i
  i = min if i < min
  i = max if i > max
  [ i ]
end

def parse_list(item, min, max)
  item.split(',').inject([]) { |r, i|
    r.push(parse_range(i, min, max))
  }.flatten
end

def parse_range(item, min, max)
  i = item.index('-')
  j = item.index('/')
  return item.to_i if (not i and not j)
  inc = j ? item[j + 1..-1].to_i : 1
  istart = -1
  iend = -1
  if i
    istart = item[0..i - 1].to_i
    iend = if j
      item[i + 1..j - 1].to_i
    else
      item[i + 1..-1].to_i
    end
  else # case */x
    istart = min
    iend = max
  end
  istart = min if istart < min
  iend = max if iend > max
  result = []
  value = istart
  loop do
    result << value
    value = value + inc
    break if value > iend
  end
  result
end

def parse_weekdays(item)
  return nil if item == '*'
  items = item.downcase.split(',')
  weekdays = nil
  monthdays = nil
  items.each do |it|
    if it.match(/#[12345]$/)
      raise ArgumentError.new(
        "ranges are not supported for monthdays (#{it})"
      ) if it.index('-')
      (monthdays ||= []) << it
    else
      WEEKDAYS.each_with_index { |a, i| it.gsub!(/#{a}/, i.to_s) }
      its = it.index('-') ? parse_range(it, 0, 7) : [ Integer(it) ]
      its = its.collect { |i| i == 7 ? 0 : i }
      (weekdays ||= []).concat(its)
    end
  end
  weekdays = weekdays.uniq if weekdays
  [ weekdays, monthdays ]
end

def sub_match?(value, values)
  values.nil? || values.include?(value)
end

def to_array
  [
    @seconds,
    @minutes,
    @hours,
    @days,
    @months,
    @weekdays,
    @monthdays,
    @timezone ? @timezone.name : nil
  ]
end