module Mousetrap
  class Resource
    include HTTParty
    headers 'User-Agent' => 'Mousetrap Ruby Client'
    base_uri 'https://cheddargetter.com'

    def initialize(hash={})
      hash.each do |key, value|
        self.send("#{key}=", value)
      end
    end

    def self.[](code)
      # Example error message:
      #
      # { "error" => "Resource not found: Customer not found for
      #    code=cantfindme within productCode=MOUSETRAP_TEST"}

      response = get_resource plural_resource_name, code

      if response['error']
        if response['error'] =~ /not found/
          return nil
        else
          raise response['error']
        end
      end

      build_resource_from response
    end

    def self.destroy_all
      all.each { |object| object.destroy }
    end

    def self.exists?(code)
      !self[code].nil?
    end

    def self.new_from_api(attributes)
      new(attributes_from_api(attributes))
    end

    def destroy
      member_action 'delete' unless new_record?
    end

    def exists?
      self.class.exists?(code)
    end

    def new?
      id.nil?
    end

    alias new_record? new?


    protected

    def self.build_resource_from(response)
      resource_attributes = extract_resources(response)
      new_from_api(resource_attributes)
    end

    def self.build_resources_from(response)
      resources = []

      response_resources = extract_resources(response)

      if response_resources.is_a?(Array)
        extract_resources(response).each do |resource_attributes|
          resources << new_from_api(resource_attributes)
        end
      else
        resources << new_from_api(response_resources)
      end

      resources
    end

    def self.delete_resource(resource, code)
      member_action(resource, 'delete', code)
    end

    def self.extract_resources(response)
      response[plural_resource_name][singular_resource_name]
    end

    def self.get_resource(resource, code)
      get resource_path(resource, 'get', code)
    end

    def self.get_resources(resource)
      get resource_path(resource, 'get')
    end

    def self.member_action(resource, action, code, attributes = nil)
      path = resource_path(resource, action, code)

      if attributes
        post path, :body => attributes
      else
        post path
      end
    end

    def self.post_resource(resource, action, attributes)
      path = resource_path(resource, action)
      post path, :body => attributes
    end

    def self.put_resource(resource, action, code, attributes)
      member_action(resource, action, code, attributes)
    end

    def self.raise_api_unsupported_error
      raise NotImplementedError, API_UNSUPPORTED
    end

    def self.resource_path(resource, action, code = nil)
      path = "/xml/#{resource}/#{action}/productCode/#{uri_encode(Mousetrap.product_code)}"
      path += "/code/#{uri_encode(code)}" if code
      path
    end

    def self.uri_encode(value)
      URI.encode(value.to_s, Regexp.new("[^#{URI::PATTERN::UNRESERVED}]"))
    end

    def member_action(action)
      self.class.member_action(self.class.plural_resource_name, action, code)
    end
  end
end