brynary/rack-bug

# encoding: utf-8
require "erb"

module Rack
  class Bug

    module Render
      include ERB::Util

      def signed_params(hash)
        ParamsSignature.sign(request, hash)
      end

      module CompiledTemplates
      end
      include CompiledTemplates

      def render_template(filename, local_assigns = {})
        compile(filename, local_assigns)
        render_symbol = method_name(filename, local_assigns)
        send(render_symbol, local_assigns)
      end

      def compile(filename, local_assigns)
        render_symbol = method_name(filename, local_assigns)

        if !CompiledTemplates.instance_methods.include?(render_symbol.to_s)
          compile!(filename, local_assigns)
        end
      end

      def compile!(filename, local_assigns)
        render_symbol = method_name(filename, local_assigns)
        locals_code = local_assigns.keys.map { |key| "#{key} = local_assigns[:#{key}];" }.join

        source = <<-end_src
          def #{render_symbol}(local_assigns)
            #{locals_code}
            #{compiled_source(filename)}
          end
        end_src

        CompiledTemplates.module_eval(source, filename, 0)
      end

      def compiled_source(filename)
        ::ERB.new(::File.read(::File.dirname(__FILE__) + "/../bug/views/#{filename}.html.erb"), nil, "-").src
      end

      def method_name(filename, local_assigns)
        if local_assigns && local_assigns.any?
          method_name = method_name_without_locals(filename).dup
          method_name << "_locals_#{local_assigns.keys.map { |k| k.to_s }.sort.join('_')}"
        else
          method_name = method_name_without_locals(filename)
        end
        method_name.to_sym
      end

      def method_name_without_locals(filename)
        filename.split("/").join("_")
      end

    end

  end
end