require 'rails_helper'

describe Scheduler::AccountsStatusesCleanupScheduler do
  subject { described_class.new }

  let!(:account1)  { Fabricate(:account, domain: nil) }
  let!(:account2)  { Fabricate(:account, domain: nil) }
  let!(:account3)  { Fabricate(:account, domain: nil) }
  let!(:account4)  { Fabricate(:account, domain: nil) }
  let!(:remote)    { Fabricate(:account) }

  let!(:policy1)   { Fabricate(:account_statuses_cleanup_policy, account: account1) }
  let!(:policy2)   { Fabricate(:account_statuses_cleanup_policy, account: account3) }
  let!(:policy3)   { Fabricate(:account_statuses_cleanup_policy, account: account4, enabled: false) }

  let(:queue_size)       { 0 }
  let(:queue_latency)    { 0 }
  let(:process_set_stub) do
    [
      {
        'concurrency' => 2,
        'queues' => %w(push default),
      },
    ]
  end
  let(:retry_size) { 0 }

  before do
    queue_stub = double
    allow(queue_stub).to receive(:size).and_return(queue_size)
    allow(queue_stub).to receive(:latency).and_return(queue_latency)
    allow(Sidekiq::Queue).to receive(:new).and_return(queue_stub)
    allow(Sidekiq::ProcessSet).to receive(:new).and_return(process_set_stub)

    sidekiq_stats_stub = double
    allow(sidekiq_stats_stub).to receive(:retry_size).and_return(retry_size)
    allow(Sidekiq::Stats).to receive(:new).and_return(sidekiq_stats_stub)

    # Create a bunch of old statuses
    10.times do
      Fabricate(:status, account: account1, created_at: 3.years.ago)
      Fabricate(:status, account: account2, created_at: 3.years.ago)
      Fabricate(:status, account: account3, created_at: 3.years.ago)
      Fabricate(:status, account: account4, created_at: 3.years.ago)
      Fabricate(:status, account: remote, created_at: 3.years.ago)
    end

    # Create a bunch of newer statuses
    5.times do
      Fabricate(:status, account: account1, created_at: 3.minutes.ago)
      Fabricate(:status, account: account2, created_at: 3.minutes.ago)
      Fabricate(:status, account: account3, created_at: 3.minutes.ago)
      Fabricate(:status, account: account4, created_at: 3.minutes.ago)
      Fabricate(:status, account: remote, created_at: 3.minutes.ago)
    end
  end

  describe '#under_load?' do
    context 'when nothing is queued' do
      it 'returns false' do
        expect(subject.under_load?).to be false
      end
    end

    context 'when numerous jobs are queued' do
      let(:queue_size)    { 5 }
      let(:queue_latency) { 120 }

      it 'returns true' do
        expect(subject.under_load?).to be true
      end
    end

    context 'when there is a huge amount of jobs to retry' do
      let(:retry_size) { 1_000_000 }

      it 'returns true' do
        expect(subject.under_load?).to be true
      end
    end
  end

  describe '#get_budget' do
    context 'on a single thread' do
      let(:process_set_stub) { [{ 'concurrency' => 1, 'queues' => %w(push default) }] }

      it 'returns a low value' do
        expect(subject.compute_budget).to be < 10
      end
    end

    context 'on a lot of threads' do
      let(:process_set_stub) do
        [
          { 'concurrency' => 2, 'queues' => %w(push default) },
          { 'concurrency' => 2, 'queues' => ['push'] },
          { 'concurrency' => 2, 'queues' => ['push'] },
          { 'concurrency' => 2, 'queues' => ['push'] },
        ]
      end

      it 'returns a larger value' do
        expect(subject.compute_budget).to be > 10
      end
    end
  end

  describe '#perform' do
    context 'when the budget is lower than the number of toots to delete' do
      it 'deletes as many statuses as the given budget' do
        expect { subject.perform }.to change { Status.count }.by(-subject.compute_budget)
      end

      it 'does not delete from accounts with no cleanup policy' do
        expect { subject.perform }.to_not change { account2.statuses.count }
      end

      it 'does not delete from accounts with disabled cleanup policies' do
        expect { subject.perform }.to_not change { account4.statuses.count }
      end

      it 'eventually deletes every deletable toot' do
        expect { subject.perform; subject.perform; subject.perform; subject.perform }.to change { Status.count }.by(-20)
      end
    end
  end
end