module MESH

  class Entry

    include Comparable
    attr_accessor :heading, :term, :semantic_types, :semantic_relationship, :lexical_type, :regex, :case_sensitive,
                  :downcased, :locales, :loose_match_term

    @@wordy_characters = ('a'..'z').to_a + ('A'..'Z').to_a + ('0'..'9').to_a

        def <=> other
      self.term <=> other.term
    end

    def initialize(heading, entry_text, locale)
      @heading = heading
      @locales = Set.new
      @locales << locale
      @semantic_types = []
      parts = entry_text.split('|')
      if entry_text.include? '|'
        key = parts.pop
        parts.each_with_index do |part, i|
          case key[i]
            when 'a' # the term itself
              @term = part
            when 'b' # semantic type*
              @semantic_types << MESH::SemanticTypes[part]
            when 'c' # lexical type*
              @lexical_type = MESH::LexicalTypes[part]
            when 'd' # semantic relation*
              @semantic_relationship = MESH::SemanticRelationshipTypes[part]
            when 'e' # thesaurus id
            when 'f' # date
            when 's' # sort version
            when 'v' # entry version
          end
        end
      else
        @term = entry_text
      end
      if /^[A-Z0-9]+$/ =~ @term
        @regex = /(^|\W)#{Regexp.quote(@term)}(\W|$)/
        @case_sensitive = true
      else
        @regex = /(^|\W)#{Regexp.quote(@term)}(\W|$)/i
        @case_sensitive = false
      end

      @downcased = @term.downcase
      @loose_match_term = Entry.loose_match(@term)

    end

    def self.loose_match(term)
      term.gsub(/\W+/, ' ').upcase
    end

    def match_in_text(text, downcased)
      matches = []
      return matches if text.nil? || text.empty?

      loose_match = @case_sensitive ? (text.include? @term) : (downcased.include? @downcased)
      if loose_match
        text.to_enum(:scan, @regex).map do |m,|
          match = Regexp.last_match
          matches << {heading: @heading, matched: self, index: match.offset(0)}
        end
      end

      matches

    end

  end

end