require 'spec_helper'

describe Post do
  let(:author1) { Author.create! }
  let(:author2) { Author.create! }
  let(:author3) { Author.create! }
  let(:author4) { Author.create! }
  let(:tag1) { Tag.create! }
  let(:tag2) { Tag.create! }
  let(:tag3) { Tag.create! }
  let(:tag4) { Tag.create! }

  context 'has_many through:' do
    it 'return posts that have the most authors in common with post' do
      post = Post.create! authors: [author1, author2, author3]
      post1 = Post.create! authors: [author1, author4]
      post2 = Post.create! authors: [author1, author2]
      post3 = Post.create! authors: [author4]
      post4 = Post.create! authors: [author1, author2, author3]

      expect(post.similar_posts.map(&:similar_posts_model_count)).to eq([3, 2, 1])
      expect(post.similar_posts).to eq([post4, post2, post1])
    end
  end

  context 'has_and_belongs_to_many' do
    it 'return posts that have the most tags in common with post' do
      post = Post.create! tags: [tag1, tag2, tag3]
      post1 = Post.create! tags: [tag1, tag4]
      post2 = Post.create! tags: [tag1, tag2]
      post3 = Post.create! tags: [tag4]
      post4 = Post.create! tags: [tag1, tag2, tag3]

      expect(post.similar_posts_by_tag.map(&:similar_posts_by_tag_model_count)).to eq([3, 2, 1])
      expect(post.similar_posts_by_tag).to eq([post4, post2, post1])
    end
  end

  context "combination of 'has_many through:' and habtm" do
    let!(:post)  { Post.create! authors: [author1, author2, author3], tags: [tag1, tag2, tag3] }
    let!(:post1) { Post.create! authors: [author1, author2, author3], tags: [tag1, tag2, tag4] }
    let!(:post2) { Post.create! authors: [author1, author4] }
    let!(:post3) { Post.create! tags: [tag4] }
    let!(:post4) { Post.create! authors: [author1], tags: [tag1, tag2, tag3] }

    it 'return posts that have the most authors and tags in common with post' do
      expect(post.similar_posts_by_author_and_tag.map(&:similar_posts_by_author_and_tag_model_count)).to eq([5, 4, 1])
      expect(post.similar_posts_by_author_and_tag).to eq([post1, post4, post2])
    end
  end
end