require "sinatra/base"

module Sinatra

  module HeadersHelpers

  end

  helpers HeadersHelpers

  class Base
    class << self

      # TODO: add protect! method
      def get_with_headers path, opt={}, &block
        headers = opt.delete(:headers) || []
        before path do
          check_headers *headers
        end

        get path, opt, &block
      end

      def post_with_headers path, opt={}, &block
        headers = opt.delete(:headers) || []
        before path do
          check_headers *headers
        end

        post path, opt, &block

        after path do
          statistic
        end
      end

      def put_with_headers path, opt={}, &block
        headers = opt.delete(:headers) || []
        before path do
          check_headers *headers
        end

        put path, opt, &block

        after path do
          statistic
        end
      end

      def delete_with_headers path, opt={}, &block
        headers = opt.delete(:headers) || []
        before path do
          check_headers *headers
        end

        delete path, opt, &block

        after path do
          statistic
        end
      end
    end

    # Check request headers
    def check_headers *headers
      ha = (headers.empty? ? [:accept, :content_type] : headers)
      ha.each do |h|
        case h
        when :accept, "accept"
          accept_json
        when :content_type, "content_type"
          request_json
        end
      end
    end

    # Check Accept header
    #
    # Can client works with JSON?
    def accept_json
      logger.debug(request.accept)
      unless request.accept? 'application/json'
        response.headers['Accept'] = 'application/json'
        halt_response("Accept header should contains 'application/json' type", 406)
      end
    rescue NoMethodError => e
      #error in sinatra 1.4.4 (https://github.com/sinatra/sinatra/issues/844, https://github.com/sinatra/sinatra/pull/805)
      response.headers['Accept'] = 'application/json'
      halt_response("Accept header should contains 'application/json' type", 406)
    end

    # Check Content-Type header
    def request_json
      halt_response("Content-Type should be 'application/json'", 415) if request.media_type.nil? or request.media_type != 'application/json'
    end


  end
end