module Rscons
  class Program < Builder
    VARIABLE_DEFAULTS = {
      'LD' => nil,
      'OBJSUFFIX' => '.o',
      'LIBSUFFIX' => '.a',
      'LDFLAGS' => [],
      'LIBPATHS' => [],
      'LIBS' => [],
    }

    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)
        command = [
          env['LD'] || env['CC'],
          '-o', target,
          *env['LDFLAGS'],
          *sources,
          *env['LIBPATHS'].map {|lp| "-L#{lp}"},
          *env['LIBS'].map {|lib| "-l#{lib}"}
        ]
        vars = {
          'TARGET' => target,
          'SOURCES' => sources,
        }
        env.execute("LINK #{target}", command, vars)
        Cache.open.register_build(target, sources)
      end
      target
    end
  end
end