# encoding: utf-8

module Hatetepe
  class Client
    include Support::Handlers
    include Connection::Status

    attr_reader :config

    def initialize(config)
      @config = config
      @requests = []

      setup_connection
      setup_handlers
      notify_handlers(:post_init)
    end

    def request(http_method, uri)
      request = Request.new(http_method, uri)
      request.finished.fulfill
      perform(request)
      request.served.sync
    end

    def perform(request)
      @requests << request

      fiber = Fiber.new do
        notify_handlers(:perform, request)
        @connection.serialize(request)
      end
      fiber.resume
    end

    def close
      @connection.close
    end

    def receive(response)
      unless (request = correlate(response))
        raise ClientError, 'Unable to correlate with request'
      end

      setup_cleanup(request, response)
      notify_handlers(:receive, request, response)
    end

    def teardown(reason)
      while (request = @requests.shift)
        if (response = request.served.value)
          response.finished.reject(reason)
        else
          request.served.reject(reason)
        end
      end
    end

    private

    def setup_connection
      @connection =
        EM.connect(@config[:address], @config[:port], Connection::EventMachine)
      @connection.parse(method(:receive))
      @connection.closed.then(method(:teardown))
    end

    def correlate(response)
      @requests
        .detect { |request| request.served.pending? }
        .tap    { |request| request.served.fulfill(response) if request }
    end

    def setup_cleanup(request, response)
      callback = proc { @requests.delete(request) }
      response.finished.then(callback, callback)
    end
  end
end