module ATD
  module Compilation
    module Precompiler
      extend self
      def filetypes
        instance_methods(true) - [:filetypes]
      end
    end
    module Compiler
      extend self
      def filetypes
        instance_methods(true) - [:filetypes]
      end
    end

    def self.compile(name, contents)
      return contents if name.nil?
      name = name.split(".")
      extensions = name - [name.first]
      extensions.each do |extension|
        contents = Compiler.send(extension, contents) if Compiler.filetypes.include? extension.to_sym
      end
      contents
    end

    def self.pre_parse(route)
      output = route.output
      name = output
      return nil if output.nil?
      if output.include?(".") || output.is_a?(File)
        file = read_file(output)
        return nil if file.nil?
        name = (output.is_a?(File) ? File.basename(output) : output)
        file = precompile(name, file)
        route.output = file
      end
      name
    end

    class << self
      private

      def read_file(output)
        return File.read(File.join("assets/#{output}")) if output.is_a?(String) && File.exist?("assets/#{output}")
        return File.read(output) if output.is_a? File
      end

      def precompile(name, contents)
        name = name.split(".")
        extensions = name - [name.first]
        extensions.each do |extension|
          if Precompiler.filetypes.include? extension.to_sym
            contents = Precompiler.send(extension, contents)
            extensions -= [extension]
          end
        end
        contents
      end
    end
  end
end