require 'scanner'

module CodeRay
  
  class RubyScanner < Scanner
    
    RESERVED_WORDS = [
      'and', 'def', 'end', 'in', 'or', 'unless', 'begin',
      'defined?', 'ensure', 'module', 'redo', 'super', 'until',
      'BEGIN', 'break', 'do', 'next', 'rescue', 'then',
      'when', 'END', 'case', 'else', 'for', 'retry',
      'while', 'alias', 'class', 'elsif', 'if', 'not', 'return',
      'undef', 'yield',
    ]

    DEF_KEYWORDS = ['def']
    MODULE_KEYWORDS = ['class', 'module']
    DEF_NEW_STATE = WordList.new(:initial).
      add(DEF_KEYWORDS, :def_expected).
      add(MODULE_KEYWORDS, :module_expected)

    WORDS_ALLOWING_REGEXP = [
      'and', 'or', 'not', 'while', 'until', 'unless', 'if', 'elsif', 'when'
    ]
    REGEXP_ALLOWED = WordList.new(false).
      add(WORDS_ALLOWING_REGEXP, :set)
    
    PREDEFINED_CONSTANTS = [
      'nil', 'true', 'false', 'self',
      'DATA', 'ARGV', 'ARGF', '__FILE__', '__LINE__',
    ]

    IDENT_KIND = WordList.new(:ident).
      add(RESERVED_WORDS, :reserved).
      add(PREDEFINED_CONSTANTS, :pre_constant)

    METHOD_NAME = / #{IDENT} [?!]? /xo
    METHOD_NAME_EX = /
     #{METHOD_NAME}  # common methods: split, foo=, empty?, gsub!
     | \*\*?         # multiplication and power
     | [-+~]@?       # plus, minus
     | [\/%&|^`]     # division, modulo or format strings, &and, |or, ^xor, `system`
     | \[\]=?        # array getter and setter
     | <=?>? | >=?   # comparison, rocket operator
     | << | >>       # append or shift left, shift right
     | ===?          # simple equality and case equality
    /ox
    GLOBAL_VARIABLE = / \$ (?: #{IDENT} | \d+ | [~&+`'=\/,;_.<>!@0$?*":F\\] | -[a-zA-Z_0-9] ) /ox

    DOUBLEQ = / "  [^"\#\\]*  (?: (?: \#\{.*?\} | \#(?:$")?  | \\. ) [^"\#\\]*  )* "?  /ox
    SINGLEQ = / '  [^'\\]*    (?:                              \\.   [^'\\]*    )* '?  /ox
    STRING  = / #{SINGLEQ} | #{DOUBLEQ} /ox
    SHELL   = / `  [^`\#\\]*  (?: (?: \#\{.*?\} | \#(?:$`)?  | \\. ) [^`\#\\]*  )* `?  /ox
    REGEXP  = / \/ [^\/\#\\]* (?: (?: \#\{.*?\} | \#(?:$\/)? | \\. ) [^\/\#\\]* )* \/? /ox
    
    DECIMAL = /\d+(?:_\d+)*/  # doesn't recognize 09 as octal error
    OCTAL = /0_?[0-7]+(?:_[0-7]+)*/
    HEXADECIMAL = /0x[0-9A-Fa-f]+(?:_[0-9A-Fa-f]+)*/
    BINARY = /0b[01]+(?:_[01]+)*/

    EXPONENT = / [eE] [+-]? #{DECIMAL} /ox
    FLOAT = / #{DECIMAL} (?: #{EXPONENT} | \. #{DECIMAL} #{EXPONENT}? ) /
    INTEGER = /#{OCTAL}|#{HEXADECIMAL}|#{BINARY}|#{DECIMAL}/
    
    def reset
      super
      @regexp_allowed = false
    end
    
    def next_token
      return if @scanner.eos?

      kind = :error
      if @scanner.scan(/\s+/)  # in every state
        kind = :space
        @regexp_allowed = :set if @regexp_allowed or @scanner.matched.index(?\n)  # delayed flag setting

      elsif @state == :def_expected
        if @scanner.scan(/ (?: (?:#{IDENT}(?:\.|::))* | (?:@@?|$)? #{IDENT}(?:\.|::) ) #{METHOD_NAME_EX} /ox)
          kind = :method
          @state = :initial
        else
          @scanner.scan(/./)
          kind = :error
        end
        @state = :initial
        
      elsif @state == :module_expected
        if @scanner.scan(/<</)
          kind = :operator
        else
          if @scanner.scan(/ (?: #{IDENT} (?:\.|::))* #{IDENT} /ox)
            kind = :method
          else
            @scanner.scan(/./)
            kind = :error
          end
          @state = :initial
        end
        
      elsif # state == :initial
        # IDENTIFIERS, KEYWORDS
        if @scanner.scan(GLOBAL_VARIABLE)
          kind = :global_variable
        elsif @scanner.scan(/ @@ #{IDENT} /ox)
          kind = :class_variable
        elsif @scanner.scan(/ @ #{IDENT} /ox)
          kind = :instance_variable
        elsif @scanner.scan(/ __END__\n ( (?!\#CODE\#) .* )? | \#[^\n]* | =begin(?=\s).*? \n=end(?=\s|\z)(?:[^\n]*)? /x)
          kind = :comment
        elsif @scanner.scan(METHOD_NAME)
          if @last_token_dot
            kind = :ident
          else
            matched = @scanner.matched
            kind = IDENT_KIND[matched]
            if kind == :ident and matched =~ /^[A-Z]/
              kind = :constant
            elsif kind == :reserved
              @state = DEF_NEW_STATE[matched]
              @regexp_allowed = REGEXP_ALLOWED[matched]
            end
          end
          
        elsif @scanner.scan(STRING)
          kind = :string
        elsif @scanner.scan(SHELL)
          kind = :shell
        ## HEREDOCS
        elsif @scanner.scan(/\//) and @regexp_allowed
           @scanner.unscan
           @scanner.scan(REGEXP)
          kind = :regexp
        ## %strings
        elsif @scanner.scan(/:(?:#{GLOBAL_VARIABLE}|#{METHOD_NAME_EX}|#{STRING})/ox)
          kind = :global_variable
        elsif @scanner.scan(/
          \? (?:
            [^\s\\]
          | 
            \\ (?:M-\\C-|C-\\M-|M-\\c|c\\M-|c|C-|M-))? (?: \\ (?: . | [0-7]{3} | x[0-9A-Fa-f][0-9A-Fa-f] )
          )
        /ox)
          kind = :integer
          
        elsif @scanner.scan(/ [-+*\/%=<>;,|&!()\[\]{}~?] | \.\.?\.? | ::? /x)
          kind = :operator
          @regexp_allowed = :set if @scanner.matched[-1,1] =~ /[~=!<>|&^,\(\[+\-\/\*%]\z/
        elsif @scanner.scan(FLOAT)
          kind = :float
        elsif @scanner.scan(INTEGER)
          kind = :integer
        elsif @scanner.scan(/:(?:#{GLOBAL_VARIABLE}|#{METHOD_NAME_EX}|#{STRING})/ox)
          kind = :global_variable
        else
          @scanner.scan(/./m)
        end
      end
      
      token = Token.new @scanner.matched, kind

      if kind == :regexp
        token.text << @scanner.scan(/[eimnosux]*/)
      end
      
      @regexp_allowed = (@regexp_allowed == :set)  # delayed flag setting

      token
    end
  end
  
  ScannerList.register RubyScanner, 'ruby'

end

module CodeRay
  require 'scanner'

  class Highlighter

    def initialize lang
      @scanner = Scanner[lang].new
    end

    def highlight code
      @scanner.feed code
      @scanner.all_tokens.map { |t| t.inspect }.join "\n"
    end

  end

  class HTMLHighlighter < Highlighter
    
    ClassOfKind = {
      :attribute_name => 'an',
      :attribute_name_fat => 'af',
      :attribute_value => 'av',
      :attribute_value_fat => 'aw',
      :bin => 'bi',
       :char => 'ch',
      :class => 'cl',
      :class_variable => 'cv',
      :color => 'cr',
      :comment => 'c',
      :constant => 'co',
      :definition => 'df',
      :directive => 'di',
      :doc => 'do',
      :doc_string => 'ds',
      :exception => 'ex',
      :error => 'er',
      :float => 'fl',
      :function => 'fu',
      :global_variable => 'gv',
      :hex => 'hx',
      :include => 'ic',
      :instance_variable => 'iv',
      :integer => 'i',
      :interpreted => 'in',
      :label => 'la',
      :local_variable => 'lv',
      :oct => 'oc',
      :operator_name => 'on',
      :pre_constant => 'pc',
      :pre_type => 'pt',
      :predefined => 'pd',
      :preprocessor => 'pp',
      :regexp => 'rx',
      :reserved => 'r',
      :shell => 'sh',
      :string => 's',
      :symbol => 'sy',
      :tag => 'ta',
      :tag_fat => 'tf',
      :tag_special => 'ts',
      :type => 'ty',
      :variable => 'v',
      :xml_text => 'xt',

      :ident => :NO_HIGHLIGHT,
      :operator => :NO_HIGHLIGHT,
      :space => :NO_HIGHLIGHT,
    }
    ClassOfKind[:procedure] = ClassOfKind[:method] = ClassOfKind[:function]
    ClassOfKind.default = ClassOfKind[:error] or raise 'no class found for :error!'
    
    def initialize lang, options = {}
      super lang
      
      @HTML_TAB = ' ' * options.fetch(:tabs2space, 8)
      case level = options.fetch(:level, 'xhtml')
        when 'html'
          @HTML_BR = "<BR>\n"
        when 'xhtml'
          @HTML_BR = "<br />\n"
      else
        raise "Unknown HTML level: #{level}"
      end
    end

    def highlight code
      @scanner.feed code
      
      out = ''
      while t = @scanner.next_token
        warn t.inspect if t.text.nil?
        out << to_html(t)
      end
      TEMPLATE =~ /<%CONTENT%>/
      $` + out + $'
    end
    
  private
    def to_html token
      css_class = ClassOfKind[token.kind]
      if defined? ::DEBUG and not ClassOfKind.has_key? token.kind
        warn "no token class found for :#{token.kind}"
      end
        
      text = text_to_html token.text
      if css_class == :NO_HIGHLIGHT
        text
      else
        "<span class=\"#{css_class}\">#{text}</span>"
      end
    end
    
    def text_to_html text
      return '' if text.empty?
      text = text.dup  # important
      if text.index(/["><&]/)
        text.gsub!('&', '&amp;')
        text.gsub!('"', '&quot;')
        text.gsub!('>', '&gt;')
        text.gsub!('<', '&lt;')
      end
      if text.index(/\s/)
        text.gsub!("\n", @HTML_BR)
        text.gsub!("\t", @HTML_TAB)
        text.gsub!(/^ /, '&nbsp;')
        text.gsub!('  ', ' &nbsp;')
      end
      text
    end
    
    TEMPLATE = <<-'TEMPLATE'
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html dir="ltr">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<meta http-equiv="Content-Style-Type" content="text/css">

<title>RubyBB BBCode</title>
<style type="text/css">
.code {
  width: 100%;
  background-color: #FAFAFA;
  border: 1px solid #D1D7DC;
  font-family: 'Courier New', 'Terminal', monospace;
  font-size: 10pt;
  color: black;
  vertical-align: top;
  text-align: left;
}
.code .af { color:#00C; }
.code .an { color:#007; }
.code .av { color:#700; }
.code .aw { color:#C00; }
.code .bi { color:#509; font-weight:bold; }
.code .c  { color:#888; }
.code .ch { color:#C28; font-weight:bold; }
.code .cl { color:#B06; font-weight:bold; }
.code .co { color:#036; font-weight:bold; }
.code .cr { color:#0A0; }
.code .cv { color:#369; }
.code .df { color:#099; font-weight:bold; }
.code .di { color:#088; font-weight:bold; }
.code .do { color:#970; }
.code .ds { color:#D42; font-weight:bold; }
.code .er { color:#F00; background-color:#FAA; }
.code .ex { color:#F00; font-weight:bold; }
.code .fl { color:#60E; font-weight:bold; }
.code .fu { color:#06B; font-weight:bold; }
.code .gv { color:#800; font-weight:bold; }
.code .hx { color:#058; font-weight:bold; }
.code .i  { color:#00D; font-weight:bold; }
.code .ic { color:#B44; font-weight:bold; }
.code .in { color:#B2B; font-weight:bold; }
.code .iv { color:#33B; }
.code .la { color:#970; font-weight:bold; }
.code .lv { color:#963; }
.code .oc { color:#40E; font-weight:bold; }
.code .on { color:#000; font-weight:bold; }
.code .pc { color:#038; font-weight:bold; }
.code .pd { color:#369; font-weight:bold; }
.code .pp { color:#579; }
.code .pt { color:#339; font-weight:bold; }
.code .r  { color:#080; font-weight:bold; }
.code .rx { color:#927; font-weight:bold; }
.code .s  { color:#D42; font-weight:bold; }
.code .sh { color:#B2B; font-weight:bold; }
.code .sy { color:#A60; }
.code .ta { color:#070; }
.code .tf { color:#070; font-weight:bold; }
.code .ts { color:#D70; font-weight:bold; }
.code .ty { color:#339; font-weight:bold; }
.code .v  { color:#036; }
.code .xt { color:#444; }
</style>
</head>
<body>
<div class="code">
<%CONTENT%>
</div>
<div class="validators">
<a href="http://validator.w3.org/check?uri=referer"><img src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" height="31" width="88" style="border:none;"></a>
<img style="border:0" src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!" >
</div>    
</body>
</html>
    TEMPLATE

  end

end