require "java/java"

module Buildr
  # Provides ANTLR grammar generation tasks. Require explicitly using <code>require "buildr/antlr"</code>.
  module ANTLR
    REQUIRES = [ "org.antlr:antlr:jar:3.0", "antlr:antlr:jar:2.7.7", "org.antlr:stringtemplate:jar:3.0" ]

    Java.wrapper.classpath << REQUIRES

    class << self
      def antlr(*args)
        options = Hash === args.last ? args.pop : {}
        rake_check_options options, :output, :token

        args = args.flatten.map(&:to_s).collect { |f| File.directory?(f) ? FileList[f + "/**/*.g"] : f }.flatten
        args = ["-o",  options[:output]] + args if options[:output]
        if options[:token]
          # antlr expects the token directory to exist when it starts
          mkdir_p options[:token] 
          args = ["-lib",  options[:token]] + args 
        end
        Java.wrapper do |wrapper|
          antlr_class = wrapper.import("org.antlr.Tool")
          antlr_tool = antlr_class.new_with_sig("[Ljava.lang.String;", args)
          antlr_tool.process
          #wrapper.import("org.antlr.Tool").main(args) == 0 or
          #  fail "Failed to run ANTLR, see errors above."
        end
      end
    end

    def antlr(*args)
      if Hash === args.last
        options = args.pop 
        in_package = options[:in_package].split(".")
        token = options[:token].split(".") if options[:token]
      else
        in_package = []; token = nil
      end
      file(path_to(:target, "generated/antlr")=>args.flatten) do |task|
        args = {:output=>File.join(task.name, in_package)}
        args.merge!({:token=>File.join(task.name, token)}) if token
        ANTLR.antlr task.prerequisites, args
      end         
    end

  end
  
  class Project
    include ANTLR
  end
end