module MasterView

  # Mixin services for directive implementation classes.
  #
  # Subclasses of MasterView::DirectiveBase inherit this mixin.
  #
  module DirectiveHelpers

    CRLF = "\r\n"

    # start of ERB which is evaluated but does not contribute content to the document
    ERB_EVAL_START = '<% '
    # end of ERB which is evaluated but does not contribute content to the document
    ERB_EVAL_END = ' -%>'

    # start of ERB whose evaluation results in content in the document
    ERB_CONTENT_START = '<%= '
    # end of ERB whose evaluation results in content in the document
    ERB_CONTENT_END = ' %>'

    # convert render_partial_name to file_name, ex foo/bar to foo/_bar.rhtml
    def render_partial_name_to_file_name(render_partial_name, default_extension)
      pathname = Pathname.for_path(render_partial_name)
      dir_pathname = pathname.dirname
      base = pathname.basename(pathname.extname).to_s
      filename = '_'+base
      filename += default_extension if default_extension
      path = (dir_pathname+filename).to_s
    end


    # find the last string that fully matches exactly the
    # parent tags content string array
    # It looks for something that has been output as a unit in
    # the array not a substring
    # returns the ref to the string which you can operate on
    # using replace
    def find_last_in_parent(tag, full_string)
      ret = nil
      parent = tag.parent
      unless parent.nil?
        parent.content.reverse.each do |str|
            if str.kind_of? Array # if it is a nested array check inside of it
                str.reverse.each do |s|
                    if s == full_string
                        ret = s
                        break
                    end
                end
                break if ret
            else
                if str == full_string
                    ret = str
                    break
                end
            end
        end
      end
      ret
    end

    # set the last occurence to empty string
    # returns true if found and set to empty string
    def delete_last_in_parent(tag, full_string)
      str = find_last_in_parent(tag, full_string)
      found = !str.nil?
      str.replace('') if found
      found
    end

    # find a hash value from inside a simple str containing a hash
    # non-evaling, looks for a :key => 'foo/bar' returning foo/bar string
    def find_string_val_in_string_hash(str, key_or_sym)
      key = key_or_sym.to_s
      m = str.match( Regexp.new( Regexp.escape(key)+"\s*=>\s*'([^']*)'" ) ) #try single quote
      m = str.match( Regexp.new( Regexp.escape(key)+"\s*=>\s*\"([^\"]*)\"" ) ) if m.nil? #try double quote
      return nil if m.nil?
      m[1]
    end

    #parse into array of strings, containing the various arguments without evaling
    #looks for %q{}, %q[], hash, array, function call using (), values deliminated by commas,
    def parse(str)
      AttrStringParser.parse(str)
    end

    #add single quotes around string
    def quote(str, quote_char='\'')
      quote_char+str+quote_char
    end

    # adds single quotes around string if it is a simple
    # word [a-zA-Z0-9_]* otherwise return existing string
    # also quote if empty string
    def quote_if(str)
      (str =~ /^\w*$/) ? quote(str) : str
    end

  end

end