# Treetop (http://treetop.rubyforge.org/) grammar for package definitions.

module Fig
  grammar Fig
    rule package
      optional_ws statements:(package_statement*) optional_ws {
        def to_package(directory, build_state)
          return build_state.new_package_statement(directory, statements)
        end
      }
    end

    rule package_statement
      archive / resource / retrieve / config
    end

    # Note that these are being parsed like they allow globbing despite
    # globbing not being performed.
    rule archive
      statement_start:"archive" ws resource_url {
        def to_package_statement(build_state)
          return build_state.new_asset_statement(
            Statement::Archive, statement_start, resource_url
          )
        end
      }
    end

    rule resource
      statement_start:"resource" ws resource_url {
        def to_package_statement(build_state)
          return build_state.new_asset_statement(
            Statement::Resource, statement_start, resource_url
          )
        end
      }
    end

    rule retrieve
      statement_start:"retrieve" ws var:environment_variable_name "->" path:retrieve_path ws {
        def to_package_statement(build_state)
          return build_state.new_retrieve_statement(statement_start, var, path)
        end
      }
    end

    rule retrieve_path
      [a-zA-Z0-9_/.\[\]-]+
    end

    rule config
      statement_start:"config" ws config_name ws statements:config_statement* "end" ws {
        def to_package_statement(build_state)
          return build_state.new_configuration_statement(
            statement_start, config_name, statements
          )
        end
      }
    end

    rule config_name
      [a-zA-Z0-9_.-]+
    end

    rule config_statement
      override / include / command / path / set
    end

    rule include
      statement_start:"include" ws descriptor_string ws {
        def to_config_statement(build_state)
          return build_state.new_include_statement(
            statement_start, descriptor_string
          )
        end
      }
    end

    rule override
      statement_start:"override" ws descriptor_string ws {
        def to_config_statement(build_state)
          return build_state.new_override_statement(
            statement_start, descriptor_string
          )
        end
      }
    end

    rule path
      statement_start:("add" / "append" / "path") ws name_value:[\S]+ ws {
        def to_config_statement(build_state)
          return build_state.new_environment_variable_statement(
            Statement::Path, statement_start, name_value
          )
        end
      }
    end

    rule environment_variable_name
      [a-zA-Z0-9_]+
    end

    rule set
      statement_start:"set" ws name_value:[\S]+ ws {
        def to_config_statement(build_state)
          return build_state.new_environment_variable_statement(
            Statement::Set, statement_start, name_value
          )
        end
      }
    end

    rule command
      statement_start:"command" ws string {
        def to_config_statement(build_state)
          return build_state.new_command_statement(statement_start, string)
        end
      }
    end

    rule string
      '"' value:(!'"' . )* '"' ws
    end

    rule descriptor_string
      [\S]+
    end

    rule resource_url
      # Unquoted allows globbing for files, quoted does not.
      #
      # Unquoted, anything but:
      #    @      - To allow for package substitution
      #    "<>|   - Characters not allowed in filenames on Windows
      #    \s     - Necessary for the "ws" token to work
      (url:[^@"<>|\s]+ ws)

      # Quoted, anything but:
      #    @        - To allow for package substitution
      #    "<>|     - Characters not allowed in filenames on Windows
      #    *?\[\]{} - Characters significant to Dir.glob()
      #    \s       - We just don't want these. :]  (May need to allow space.)
      / ('"' url:[^@"<>|*?\[\]{}\s]+ '"' ws)
    end

    rule ws
      [ \n\r\t]+
    end

    rule optional_ws
      [ \n\r\t]*
    end
  end
end