module Jets
  module SpecHelpers
    class Request
      attr_accessor :method, :path, :headers, :params
      def initialize(method, path, headers={}, params={})
        @method, @path, @headers, @params = method, path, headers, params
      end

      def event
        json = {}
        id_params = path.scan(%r{:([^/]+)}).flatten
        expanded_path = path.dup
        path_parameters = {}

        id_params.each do |id_param|
          raise "missing param: :#{id_param}" unless params.path_params.include? id_param.to_sym

          path_param_value = params.path_params[id_param.to_sym]
          raise "Path param :#{id_param} value cannot be blank" if path_param_value.blank?

          expanded_path.gsub!(":#{id_param}", path_param_value.to_s)
          path_parameters.deep_merge!(id_param => path_param_value.to_s)
        end

        json['resource'] = path
        json['path'] = expanded_path
        json['httpMethod'] = method.to_s.upcase
        json['pathParameters'] = path_parameters
        json['headers'] = (headers || {}).stringify_keys

        if method != :get
          json['headers']['Content-Type'] = "multipart/form-data; boundary=#{multipart_boundary}"
          body = +''
          params.body_params.to_a.each do |e|
            key, value = e
            body << multipart_item(name: key, value: value)
          end
          body << multipart_end

          json['body'] = Base64.encode64 body
          json['isBase64Encoded'] = true
        end

        params.query_params.to_a.each do |e|
          key, value = e
          json['queryStringParameters'] ||= {}
          json['queryStringParameters'][key.to_s] = value.to_s
        end

        json
      end

      def multipart_boundary
        @boundary ||= '-' * 16 + SecureRandom.hex(32)
      end

      def multipart_item(name:, value:)
        if value.is_a? File
          multipart_file(name: name, filename: File.basename(value.path),
                         data: ::IO.read(value.path))
        else
          multipart_text(name: name, text: value)
        end
      end

      def multipart_text(name:, text:)
        "--#{multipart_boundary}\r\nContent-Disposition: form-data; name=\"#{name}\"\r\n"\
        "Content-Type: text/plain\r\n\r\n#{text}\r\n"
      end

      def multipart_file(name:, filename:, data:)
        "--#{multipart_boundary}\r\nContent-Disposition: form-data; name=\"#{name}\"; "\
        "filename=\"#{filename}\"\r\n\r\n#{data}\r\n"
      end

      def multipart_end
        "--#{multipart_boundary}--"
      end

      def find_route!
        path = self.path
        path = path[0..-2] if path.end_with? '/'
        path = path[1..-1] if path.start_with? '/'

        route = Jets::Router.routes.find { |r| r.path == path && r.method == method.to_s.upcase }
        raise "Route not found: #{method.to_s.upcase} #{path}" if route.blank?

        route
      end

      def dispatch!
        route = find_route!
        controller = Object.const_get(route.controller_name).new(event, {}, route.action_name)
        response = controller.dispatch!

        if !response.is_a?(Array) || response.size != 3
          raise "Expected response to be an array of size 3. Are you rendering correctly?"
        end

        Response.new(response[0].to_i, response[2].read)
      end
    end
  end
end