module Embulk::Guess::TimeFormatGuess

def self.guess(texts)
  texts = Array(texts).map {|text| text.to_s }
  texts.reject! {|text| text == "" }
  matches = texts.map do |text|
    PATTERNS.map {|pattern| pattern.match(text) }.compact
  end.flatten
  if matches.empty?
    return nil
  elsif matches.size == 1
    return matches[0].format
  else
    match_groups = matches.group_by {|match| match.mergeable_group }.values
    best_match_group = match_groups.sort_by {|group| group.size }.last
    best_match = best_match_group.shift
    best_match_group.each {|m| best_match.merge!(m) }
    return best_match.format
  end
end