require 'spec_helper'
require 'support/example_classes'

describe Authority::Abilities do

  let(:user)           { ExampleUser.new }
  let(:resource_class) { ExampleResource }

  describe "instance methods" do

    describe "authorizer_name" do

      it "has a class attribute getter for authorizer_name" do
        expect(resource_class).to respond_to(:authorizer_name)
      end

      it "has a class attribute setter for authorizer_name" do
        expect(resource_class).to respond_to(:authorizer_name=)
      end

      it "has a default authorizer_name of 'ApplicationAuthorizer'" do
        expect(resource_class.authorizer_name).to eq("ApplicationAuthorizer")
      end

    end

    describe "authorizer" do

      it "constantizes the authorizer name as the authorizer" do
        resource_class.instance_variable_set(:@authorizer, nil)
        resource_class.authorizer_name.should_receive(:constantize)
        resource_class.authorizer
      end

      it "memoizes the authorizer to avoid reconstantizing" do
        resource_class.authorizer
        resource_class.authorizer_name.should_not_receive(:constantize)
        resource_class.authorizer
      end

      it "raises a friendly error if the authorizer doesn't exist" do
        class NoAuthorizerModel < resource_class; end ;
        NoAuthorizerModel.instance_variable_set(:@authorizer, nil)
        NoAuthorizerModel.authorizer_name = 'NonExistentAuthorizer'
        expect { NoAuthorizerModel.authorizer }.to raise_error(Authority::NoAuthorizerError)
      end

    end

  end

  describe "class methods" do

    Authority.adjectives.each do |adjective|
      method_name = "#{adjective}_by?"

      it "responds to `#{method_name}`" do
        expect(resource_class).to respond_to(method_name)
      end

      describe "#{method_name}" do

        context "when given an options hash" do

          it "delegates `#{method_name}` to its authorizer class, passing the options" do
            resource_class.authorizer.should_receive(method_name).with(user, :lacking => 'nothing')
            resource_class.send(method_name, user, :lacking => 'nothing')
          end

        end

        context "when not given an options hash" do

          it "delegates `#{method_name}` to its authorizer class, passing no options" do
            resource_class.authorizer.should_receive(method_name).with(user)
            resource_class.send(method_name, user)
          end

        end

      end

    end

  end

  describe "instance methods" do

    let(:resource_instance) { resource_class.new }

    before :each do
      @authorizer = resource_class.authorizer.new(resource_instance)
    end

    Authority.adjectives.each do |adjective|
      method_name = "#{adjective}_by?"

      it "responds to `#{method_name}`" do
        expect(resource_instance).to respond_to(method_name)
      end

      describe "#{method_name}" do

        context "when given an options hash" do

          it "delegates `#{method_name}` to a new authorizer instance, passing the options" do
            resource_class.authorizer.stub(:new).and_return(@authorizer)
            @authorizer.should_receive(method_name).with(user, :with => 'mayo')
            resource_instance.send(method_name, user, :with => 'mayo')
          end

        end

        context "when not given an options hash" do

          it "delegates `#{method_name}` to a new authorizer instance, passing no options" do
            resource_class.authorizer.stub(:new).and_return(@authorizer)
            @authorizer.should_receive(method_name).with(user)
            resource_instance.send(method_name, user)
          end

        end

      end

    end

    it "provides an accessor for its authorizer" do
      expect(resource_instance).to respond_to(:authorizer)
    end

    # When checking instance methods, we want to ensure that every check uses a new
    # instance of the authorizer. Otherwise, you might check, make a change to the
    # model instance, check again, and get an outdated answer.
    it "always creates a new authorizer instance when accessing the authorizer" do
      resource_instance.class.authorizer.should_receive(:new).with(resource_instance).twice
      2.times { resource_instance.authorizer }
    end

  end

end