Add reshare service

class ReshareService

  def initialize(user=nil)

    @user = user

  end

  def create(post_id)

    post = post_service.find!(post_id)

    post = post.absolute_root if post.is_a? Reshare

    user.reshare!(post)

  end

  def find_for_post(post_id)

    reshares = post_service.find!(post_id).reshares

    user ? reshares.order("author_id = #{user.person.id} DESC") : reshares

  end

  private

  attr_reader :user

  def post_service

    @post_service ||= PostService.new(user)

  end

end

describe ReshareService do

  let(:post) { alice.post(:status_message, text: "hello", public: true) }

  describe "#create" do

    it "doesn't create a reshare of my own post" do

      expect {

        ReshareService.new(alice).create(post.id)

      }.not_to raise_error

    end

    it "creates a reshare of a post of a contact" do

      expect {

        ReshareService.new(bob).create(post.id)

      }.not_to raise_error

    end

    it "attaches the reshare to the post" do

      reshare = ReshareService.new(bob).create(post.id)

      expect(post.reshares.first.id).to eq(reshare.id)

    end

    it "reshares the original post when called with a reshare" do

      reshare = ReshareService.new(bob).create(post.id)

      reshare2 = ReshareService.new(eve).create(reshare.id)

      expect(post.reshares.map(&:id)).to include(reshare2.id)

    end

    it "fails if the post does not exist" do

      expect {

        ReshareService.new(bob).create("unknown id")

      }.to raise_error ActiveRecord::RecordNotFound

    end

    it "fails if the post is not public" do

      post = alice.post(:status_message, text: "hello", to: alice.aspects.first)

      expect {

        ReshareService.new(bob).create(post.id)

      }.to raise_error ActiveRecord::RecordInvalid

    end

    it "fails if the user already reshared the post" do

      ReshareService.new(bob).create(post.id)

      expect {

        ReshareService.new(bob).create(post.id)

      }.to raise_error ActiveRecord::RecordInvalid

    end

    it "fails if the user already reshared the original post" do

      reshare = ReshareService.new(bob).create(post.id)

      expect {

        ReshareService.new(bob).create(reshare.id)

      }.to raise_error ActiveRecord::RecordInvalid

    end

  end

  describe "#find_for_post" do

    context "with user" do

      it "returns reshares for a public post" do

        reshare = ReshareService.new(bob).create(post.id)

        expect(ReshareService.new(eve).find_for_post(post.id)).to include(reshare)

      end

      it "returns reshares for a visible private post" do

        post = alice.post(:status_message, text: "hello", to: alice.aspects.first)

        expect(ReshareService.new(bob).find_for_post(post.id)).to be_empty

      end

      it "doesn't return reshares for a private post the user can not see" do

        post = alice.post(:status_message, text: "hello", to: alice.aspects.first)

        expect {

          ReshareService.new(eve).find_for_post(post.id)

        }.to raise_error ActiveRecord::RecordNotFound

      end

      it "returns the user's reshare first" do

        [alice, bob, eve].map {|user| ReshareService.new(user).create(post.id) }

        [alice, bob, eve].each do |user|

          expect(

            ReshareService.new(user).find_for_post(post.id).first.author.id

          ).to be user.person.id

        end

      end

    end

    context "without user" do

      it "returns reshares for a public post" do

        reshare = ReshareService.new(alice).create(post.id)

        expect(ReshareService.new.find_for_post(post.id)).to include(reshare)

      end

      it "doesn't return reshares a for private post" do

        post = alice.post(:status_message, text: "hello", to: alice.aspects.first)

        expect {

          ReshareService.new.find_for_post(post.id)

        }.to raise_error Diaspora::NonPublic

      end

    end

    it "returns all reshares of a post" do

      reshares = [alice, bob, eve].map {|user| ReshareService.new(user).create(post.id) }

      expect(ReshareService.new.find_for_post(post.id)).to match_array(reshares)

    end

  end

end