module Sprockets::Processing

def add_engine_to_trail(ext, klass)
  @trail.append_extension(ext.to_s)
  if klass.respond_to?(:default_mime_type) && klass.default_mime_type
    if format_ext = extension_for_mime_type(klass.default_mime_type)
      @trail.alias_extension(ext.to_s, format_ext)
    end
  end
end

def bundle_processors(mime_type = nil)
  if mime_type
    @bundle_processors[mime_type].dup
  else
    deep_copy_hash(@bundle_processors)
  end
end

def css_compressor
  bundle_processors('text/css').detect { |klass|
    klass.respond_to?(:name) &&
      klass.name == 'Sprockets::Processor (css_compressor)'
  }
end

def css_compressor=(compressor)
  unregister_bundle_processor 'text/css', :css_compressor
  return unless compressor
  register_bundle_processor 'text/css', :css_compressor do |context, data|
    compressor.compress(data)
  end
end

def format_extensions
  @trail.extensions - @engines.keys
end

def js_compressor
  bundle_processors('application/javascript').detect { |klass|
    klass.respond_to?(:name) &&
      klass.name == 'Sprockets::Processor (js_compressor)'
  }
end

def js_compressor=(compressor)
  unregister_bundle_processor 'application/javascript', :js_compressor
  return unless compressor
  register_bundle_processor 'application/javascript', :js_compressor do |context, data|
    compressor.compress(data)
  end
end

def postprocessors(mime_type = nil)
  if mime_type
    @postprocessors[mime_type].dup
  else
    deep_copy_hash(@postprocessors)
  end
end

def preprocessors(mime_type = nil)
  if mime_type
    @preprocessors[mime_type].dup
  else
    deep_copy_hash(@preprocessors)
  end
end

def processors(*args)
  preprocessors(*args)
end

def register_bundle_processor(mime_type, klass, &block)
  if block_given?
    name  = klass.to_s
    klass = Class.new(Processor) do
      @name      = name
      @processor = block
    end
  end
  @bundle_processors[mime_type].push(klass)
end

def register_postprocessor(mime_type, klass, &block)
  if block_given?
    name  = klass.to_s
    klass = Class.new(Processor) do
      @name      = name
      @processor = block
    end
  end
  @postprocessors[mime_type].push(klass)
end

def register_preprocessor(mime_type, klass, &block)
  if block_given?
    name  = klass.to_s
    klass = Class.new(Processor) do
      @name      = name
      @processor = block
    end
  end
  @preprocessors[mime_type].push(klass)
end

def register_processor(*args, &block)
  register_preprocessor(*args, &block)
end

def unregister_bundle_processor(mime_type, klass)
  if klass.is_a?(String) || klass.is_a?(Symbol)
    klass = @bundle_processors[mime_type].detect { |cls|
      cls.respond_to?(:name) &&
        cls.name == "Sprockets::Processor (#{klass})"
    }
  end
  @bundle_processors[mime_type].delete(klass)
end

def unregister_postprocessor(mime_type, klass)
  if klass.is_a?(String) || klass.is_a?(Symbol)
    klass = @postprocessors[mime_type].detect { |cls|
      cls.respond_to?(:name) &&
        cls.name == "Sprockets::Processor (#{klass})"
    }
  end
  @postprocessors[mime_type].delete(klass)
end

def unregister_preprocessor(mime_type, klass)
  if klass.is_a?(String) || klass.is_a?(Symbol)
    klass = @preprocessors[mime_type].detect { |cls|
      cls.respond_to?(:name) &&
        cls.name == "Sprockets::Processor (#{klass})"
    }
  end
  @preprocessors[mime_type].delete(klass)
end

def unregister_processor(*args)
  unregister_preprocessor(*args)
end