require 'multi_json'
require 'saorin/request'
require 'saorin/response'
require 'saorin/adapters/clients'

module Saorin
  module Adapters
    module Clients
      class Base
        CONTENT_TYPE = 'application/json'.freeze

        def initialize(options = {})
        end

        def call(method, *args)
          apply Saorin::Request.new(method, args, :id => seqid!)
        end

        def notify(method, *args)
          apply Saorin::Request.new(method, args)
        end

        def apply(request)
          response = send_request request.to_json
          content = process_response response
          raise content if content.is_a?(Saorin::RPCError)
          content
        end

        protected

        def send_request(content)
          raise NotImplementedError
        end

        def process_response(content)
          response = parse_response content
          if response.is_a?(::Array)
            response.map { |res| handle_response res }
          else
            handle_response response
          end
        rescue Saorin::InvalidResponse => e
          raise e
        rescue => e
          p e
          print e.backtrace.join("\t\n")
          raise Saorin::InvalidResponse, e.to_s
        end

        def parse_response(content)
          MultiJson.decode content
        rescue MultiJson::LoadError => e
          raise Saorin::InvalidResponse, e.to_s
        end

        def to_content(response)
          return nil if response.nil?
          if response.error?
            code, message, data = response.error.values_at('code', 'message', 'data')
            error_class = Saorin.code_to_error code
            raise Error, 'unknown error code' unless error_class
            error_class.new message, :code => code, :data => data
          else
            response.result
          end
        end

        def handle_response(hash)
          return nil if hash.nil?
          response = Response.from_hash(hash)
          response.validate
          to_content response
        end

        def seqid
          @@seqid ||= 0
        end

        def seqid=(value)
          @@seqid = value
          @@seqid = 0 if @@seqid >= (1 << 31)
          @@seqid
        end

        def seqid!
          id = self.seqid
          self.seqid += 1
          id
        end
      end
    end
  end
end