# frozen_string_literal: true

require 'acfs/service/middleware'

module Acfs
  # User {Acfs::Service} to define your services. That includes
  # an identity used to identify the service in configuration files
  # and middlewares the service uses.
  #
  # Configure your service URLs in a YAML file loaded in an
  # initializer using the identity as a key:
  #
  #   production:
  #     services:
  #       user_service_key: "http://users.service.org/base/path"
  #
  # @example
  #   class UserService < Acfs::Service
  #     identity :user_service_key
  #
  #     use Acfs::Middleware::MessagePackDecoder
  #   end
  #
  class Service
    attr_accessor :options

    include Service::Middleware

    # @api private
    #
    def initialize(options = {})
      @options = options
    end

    # @api private
    # @return [Location]
    #
    def location(resource_class, opts = {})
      opts.reverse_merge! options

      action = opts[:action] || :list

      path = begin
        if opts[:path].is_a?(Hash) && opts[:path].key?(action)
          opts[:path].fetch(action)
        else
          path = if opts[:path].is_a?(Hash)
                   opts[:path][:all].to_s
                 else
                   opts[:path].to_s
                 end

          if path.blank?
            path = (resource_class.name || 'class').pluralize.underscore
          end

          resource_class.location_default_path(action, path.strip)
        end
      end

      if path.nil?
        raise ArgumentError.new "Location for `#{action}' explicit disabled by set to nil."
      end

      Location.new [self.class.base_url.to_s, path.to_s].join('/')
    end

    class << self
      # @api public
      #
      # @overload identity()
      #   Return configured identity key or derive key from class name.
      #
      #   @return [Symbol] Service identity key.
      #
      # @overload identity(identity)
      #   Set identity key.
      #
      #   @param [#to_s] identity New identity key.
      #   @return [Symbol] New set identity key.
      #
      def identity(identity = nil)
        @identity = identity.to_s.to_sym unless identity.nil?
        @identity ||= name.to_sym
      end

      # @api private
      # @return [String]
      #
      def base_url
        unless (base = Acfs::Configuration.current.locate identity)
          raise ArgumentError.new \
            "#{identity} not configured. Add `locate '" \
            "#{identity.to_s.underscore}', 'http://service.url/'` " \
            'to your configuration.'
        end

        base.to_s
      end
    end
  end
end