# frozen_string_literal: true
require 'rails_helper'

RSpec.describe Booru::VotingEngine do
  before(:each) do
    @post = create(:post)
    @engine = Booru::VotingEngine.new(create(:user), @post)
  end

  it 'should upvote a post' do
    @engine.vote!(:up)

    expect(@post.upvotes_count).to eq 1
    expect(@post.downvotes_count).to eq 0
    expect(@post.score).to eq 1
  end

  it 'should downvote a post' do
    @engine.vote!(:down)

    expect(@post.upvotes_count).to eq 0
    expect(@post.downvotes_count).to eq 1
    expect(@post.score).to eq -1
  end

  it 'should upvote and then downvote a post' do
    @engine.vote!(:up)
    @engine.vote!(:down)

    expect(@post.upvotes_count).to eq 0
    expect(@post.downvotes_count).to eq 1
    expect(@post.score).to eq -1
  end

  it 'should ignore duplicate votes' do
    @engine.vote!(:up)
    @engine.vote!(:up)

    expect(@post.upvotes_count).to eq 1
    expect(@post.downvotes_count).to eq 0
    expect(@post.score).to eq 1
  end

  it 'should correctly unvote' do
    @engine.vote!(:up)
    @engine.unvote!

    expect(@post.upvotes_count).to eq 0
    expect(@post.downvotes_count).to eq 0
    expect(@post.score).to eq 0
  end

  it 'should correctly toggle from no vote to an upvote' do
    @engine.toggle_vote!(:up)

    expect(@post.upvotes_count).to eq 1
    expect(@post.downvotes_count).to eq 0
    expect(@post.score).to eq 1
  end

  it 'should correctly toggle from no vote to a downvote' do
    @engine.toggle_vote!(:down)

    expect(@post.upvotes_count).to eq 0
    expect(@post.downvotes_count).to eq 1
    expect(@post.score).to eq -1
  end

  it 'should correctly toggle an upvote on and then off' do
    @engine.toggle_vote!(:up)
    @engine.toggle_vote!(:up)

    expect(@post.upvotes_count).to eq 0
    expect(@post.downvotes_count).to eq 0
    expect(@post.score).to eq 0
  end

  it 'should correctly toggle from an upvote to a downvote' do
    @engine.toggle_vote!(:up)
    @engine.toggle_vote!(:down)

    expect(@post.upvotes_count).to eq 0
    expect(@post.downvotes_count).to eq 1
    expect(@post.score).to eq -1
  end

  it 'should correctly count votes' do
    1.upto(25) do |_n|
      direction = [:up, :down].sample

      @engine.vote!(direction)
    end

    expect(@post.score).to be_between(-1, 1)
    expect(@post.upvotes_count).to be_between(0, 1)
    expect(@post.downvotes_count).to be_between(0, 1)
    expect(@post.upvotes_count).to_not eq @post.downvotes_count
  end

  it 'should not cause an off-by-one error' do
    1.upto(10) do |_n|
      Booru::VotingEngine.new(create(:user), @post).vote! :up
    end

    @engine.vote! :down

    expect(@post.score).to eq 9
    expect(@post.upvotes_count).to eq 10
    expect(@post.downvotes_count).to eq 1
  end

  it 'should fave a post' do
    @engine.fave!(true)

    expect(@post.faves_count).to eq 1
    expect(@post.upvotes_count).to eq 1
  end

  it 'should hide a post' do
    @engine.hide!(true)

    expect(@post.hides_count).to eq 1
  end

  it 'should toggle a fave on a post' do
    @engine.toggle_fave!

    expect(@post.faves_count).to eq 1
    expect(@post.upvotes_count).to eq 1
  end

  it 'should toggle a fave twice' do
    @engine.toggle_fave!
    @engine.toggle_fave!

    expect(@post.faves_count).to eq 0
    expect(@post.upvotes_count).to eq 1
  end

  # it "does not have a race condition" do
  #   threads = []
  #
  #   10.times do
  #     threads << Process.fork {
  #       user = create(:user)
  #       engine = Booru::VotingEngine.new(user, @post)
  #       15.times do
  #         engine.vote!([:up, :down].sample)
  #       end
  #     }
  #   end
  #
  #   threads.each { |t| Process.waitpid(t) }
  #
  #   expect(@post.upvotes_count).to eq @post.upvotes.count
  #   expect(@post.downvotes_count).to eq @post.downvotes.count
  #   expect(@post.score).to eq @post.upvotes_count - @post.downvotes_count
  # end
end