module Rscons
  class Program < Builder
    def self.default_variables(env)
      {
        'LD' => nil,
        'OBJSUFFIX' => '.o',
        'LIBSUFFIX' => '.a',
        'LDFLAGS' => [],
        'LIBPATHS' => [],
        'LIBS' => [],
        'LDCOM' => ['$LD', '-o', '$TARGET', '$LDFLAGS', '$SOURCES', '-L$[LIBPATHS]', '-l$[LIBS]']
      }
    end

    def run(env, target, sources)
      sources = [sources] if sources.is_a?(String)
      # convert sources to object file names
      sources = sources.map do |source|
        if source =~ /#{env['OBJSUFFIX']}$/ or source =~ /#{env['LIBSUFFIX']}$/
          source
        else
          builder_class = env.builders.values.find { |klass| klass.produces?(env, env['OBJSUFFIX']) }
          if builder_class
            builder = builder_class.new
            builder.run(env, env.stem(source) + env['OBJSUFFIX'], source)
          else
            raise "No builder found to convert input source #{source.inspect} to an object file."
          end
        end
      end
      unless Cache.open.up_to_date?(target, sources)
        vars = {
          'TARGET' => target,
          'SOURCES' => sources,
          'LD' => env['LD'] || env['CC'], # TODO: figure out whether to use CC or CXX
        }
        env.execute("LD #{target}", env['LDCOM'], vars)
        Cache.open.register_build(target, sources)
      end
      target
    end
  end
end