# HtmlLogParser class, a subclass of BasicParser.
# Used for parse()ing HTML logs.

require 'balance_tags_c'

module Pidgin2Adium
  class HtmlLogParser < BasicParser
    def initialize(src_path, user_aliases)
      super(src_path, user_aliases)
      @timestamp_rx = '\(((?:\d{4}-\d{2}-\d{2} )?\d{1,2}:\d{1,2}:\d{1,2}(?: [AP]M)?)\)'

      # @line_regex matches a line in an HTML log file other than the
      # first time matches on either "2008-11-17 14:12" or "14:12"
      # @line_regex match obj:
      # 0: timestamp, extended or not
      # 1: screen name or alias, if alias set
      # 2: "&lt;AUTO-REPLY&gt;" or nil
      # 3: message body
      # The ":" is optional to allow for strings like "(17:12:21) <b>***Gabe B-W</b> is confused<br/>"
      @line_regex = /#{@timestamp_rx} ?<b>(.+?) ?(&lt;AUTO-REPLY&gt;)?:?<\/b> ?(.+)<br ?\/>/o
      # @line_regex_status matches a status line
      # @line_regex_status match obj:
      # 0: timestamp
      # 1: status message
      @line_regex_status = /#{@timestamp_rx} ?<b> (.+)<\/b><br ?\/>/o
    end

    # Returns a cleaned string.
    # Removes the following tags from _text_:
    # * html
    # * body
    # * font
    # * a with no innertext, e.g. <a href="blah"></a>
    # And removes the following style declarations:
    # * color: #000000 (just turns text black)
    # * font-family
    # * font-size
    # * background
    # * em (really it's changed to <span style="font-style: italic;">)
    # Since each <span> has only one style declaration, spans with these
    # declarations are removed (but the text inside them is preserved).
    def cleanup(text)
      # Sometimes this is in there. I don't know why.
      text.gsub!(%r{&lt;/FONT HSPACE='\d'>}, '')
      # We can remove <font> safely since Pidgin and Adium both show bold
      # using <span style="font-weight: bold;"> except Pidgin uses single
      # quotes while Adium uses double quotes.
      text.gsub!(/<\/?(?:html|body|font)(?: .+?)?>/, '') # very important!

      text.tr!("\r", '')
      # Remove empty lines
      text.gsub!("\n\n", "\n")

      # Remove newlines that end the file, since they screw up the
      # newline -> <br/> conversion
      text.gsub!(/\n\Z/, '')

      # Replace newlines with "<br/>" unless they end a chat line.
      # This must go after we remove <font> tags.
      text.gsub!(/\n(?!#{@timestamp_rx})/, '<br/>')

      # These empty links are sometimes appended to every line in a chat,
      # for some weird reason. Remove them.
      text.gsub!(%r{<a href=['"].+?['"]>\s*?</a>}, '')

      # Replace single quotes inside tags with double quotes so we can
      # easily change single quotes to entities.
      # For spans, removes a space after the final declaration if it exists.
      text.gsub!(/<span style='([^']+?;) ?'>/, '<span style="\1">')
      text.gsub!(/([a-z]+=)'(.+?)'/, '\1"\2"')
=begin
      text.gsub!(/<a href='(.+?)'>/, '<a href="\1">')
      text.gsub!(/<img src='([^']+?)'/, '<img src="\1"')
      text.gsub!(/ alt='([^']+?)'/, ' alt="\1"')
=end
      text.gsub!("'", '&apos;')

      # This actually does match stuff, but doesn't group it correctly. :(
      # text.gsub!(%r{<span style="((?:.+?;)+)">(.*?)</span>}) do |s|
      text.gsub!(%r{<span style="(.+?)">(.*?)</span>}) do |s|
        # Remove empty spans.
        next if $2 == ''

        # style = style declaration
        # innertext = text inside <span>
        style, innertext = $1, $2
        # TODO: replace double quotes with "&quot;", but only outside tags; may still be tags inside spans
        # innertext.gsub!("")

        styleparts = style.split(/; ?/)
        styleparts.map! do |p|
          if p[0,5] == 'color'
            if p.include?('color: #000000')
              next
            elsif p =~ /(color: #[0-9a-fA-F]{6})(>.*)?/
              # Regarding the bit with the ">", sometimes this happens:
              # <span style="color: #000000>today;">today was busy</span>
              # Then p = "color: #000000>today"
              # Or it can end in ">;", with no text before the semicolon.
              # So keep the color but remove the ">" and anything following it.
              next($1)
            end
          else
            # don't remove font-weight
            case p
            when /^font-family/ then next
            when /^font-size/ then next
            when /^background/ then next
            end
          end
        end.compact!
        unless styleparts.empty?
          style = styleparts.join('; ')
          innertext = "<span style=\"#{style};\">#{innertext}</span>"
        end
        innertext
      end
      # Pidgin uses <em>, Adium uses <span>
      if text.gsub!('<em>', '<span style="font-style: italic;">')
        text.gsub!('</em>', '</span>')
      end
      return text
    end
  end # END HtmlLogParser class
end