class RPMSpec
    attr_reader :spec
    def initialize(spec)
      @tags = Hash.new {|h,k| h[k] = []}
      @defines = {}
      @spec = spec
      @sections = Hash.new {|h,k| h[k] = []}
      #@rpm_build_dir = rpm_build_dir

      parse
    end

    def tags(name)
      if @tags.include? name.to_s.downcase
        @tags[name.to_s.downcase]
      else
        nil
      end
    end

    def tag(name)
      t = tags(name)
      t && t.first
    end


    def sources
      @tags.map do |k,v|
        if k =~ /source[0-9]+/
          v
        else
          nil
        end
      end.compact.flatten
    end

    private

    def parse
      lines = spec.scan(/^(.*?[^\\])\n+/m).flatten.reject do |l|
        l =~ /^#/ || l.size == 0
      end.map do |l|
        l.gsub(/\\$/, '')
      end

      parse_lines(lines)
    end

    def parse_lines(lines, cur_section=nil)
      while !lines.empty?
        l = lines.shift

        case l
        when /^%define\s+(.*)$/m
          parse_define($1)
        when /^(.*?):\s*(.*)$/m # is it a tag def
          @tags[$1.downcase] << process_val($2)
        when /^%([a-z]*)\s*$/m
          section = $1
          parse_lines(lines, section)
        else
          @sections[cur_section] << process_val(l)
        end
      end
    end

    def parse_define(rest)
      key, val = rest.split(/\s+/m, 2)
      @defines[key] = process_val(val)
    end

    def process_val(str)
      str.gsub(/%\{(.*?)\}/) do |match|
        d = @defines[$1] || tag($1)
        if d
          d
        else
          match
        end
      end
    end

  end