require 'spec_helper'

RSpec.describe Shoryuken::Polling::WeightedRoundRobin do
  let(:queue1) { 'shoryuken' }
  let(:queue2) { 'uppercut' }
  let(:queues) { [] }
  subject { Shoryuken::Polling::WeightedRoundRobin.new(queues) }

  describe '#next_queue' do
    it 'cycles' do
      # [shoryuken, 2]
      # [uppercut,  1]
      queues << queue1
      queues << queue1
      queues << queue2

      expect(subject.next_queue).to eq(queue1)
      expect(subject.next_queue).to eq(queue2)
      expect(subject.next_queue).to eq(queue1)
    end

    it 'returns nil if there are no active queues' do
      expect(subject.next_queue).to eq(nil)
    end

    it 'unpauses queues whose pause is expired' do
      # [shoryuken, 2]
      # [uppercut,  1]
      queues << queue1
      queues << queue1
      queues << queue2

      allow(subject).to receive(:delay).and_return(10)

      now = Time.now
      allow(Time).to receive(:now).and_return(now)

      # pause the first queue
      subject.messages_found(queue1, 0)
      expect(subject.next_queue).to eq(queue2)

      now += 5
      allow(Time).to receive(:now).and_return(now)

      # pause the second queue
      subject.messages_found(queue2, 0)
      expect(subject.next_queue).to eq(nil)

      # queue1 should be unpaused now
      now += 6
      allow(Time).to receive(:now).and_return(now)
      expect(subject.next_queue).to eq(queue1)

      # queue1 should be unpaused and added to the end of queues now
      now += 6
      allow(Time).to receive(:now).and_return(now)
      expect(subject.next_queue).to eq(queue1)
      expect(subject.next_queue).to eq(queue2)
    end
  end

  describe '#messages_found' do
    it 'pauses a queue if there are no messages found' do
      # [shoryuken, 2]
      # [uppercut,  1]
      queues << queue1
      queues << queue1
      queues << queue2

      expect(subject).to receive(:pause).with(queue1).and_call_original
      subject.messages_found(queue1, 0)
      expect(subject.instance_variable_get(:@queues)).to eq([queue2])
    end

    it 'increased the weight if message is found' do
      # [shoryuken, 2]
      # [uppercut,  1]
      queues << queue1
      queues << queue1
      queues << queue2

      expect(subject.instance_variable_get(:@queues)).to eq([queue1, queue2])
      subject.messages_found(queue1, 1)
      expect(subject.instance_variable_get(:@queues)).to eq([queue1, queue2, queue1])
    end

    it 'respects the maximum queue weight' do
      # [shoryuken, 2]
      # [uppercut,  1]
      queues << queue1
      queues << queue1
      queues << queue2

      subject.messages_found(queue1, 1)
      subject.messages_found(queue1, 1)
      expect(subject.instance_variable_get(:@queues)).to eq([queue1, queue2, queue1])
    end
  end

  describe '#delay' do
    it 'sets delay based on group' do
      delay_polling = Shoryuken::Polling::WeightedRoundRobin.new(queues, 25)
      expect(delay_polling.delay).to eq(25.0)
      expect(subject.delay).to eq(1.0)
    end
  end

  describe '#message_processed' do
    it 'removes delay from paused queue' do
      queues << queue1
      queues << queue2

      expect(subject.next_queue).to eq(queue1)
      subject.messages_found(queue1, 0) # pauses queue1

      expect(subject.active_queues).to eq([[queue2, 1]])

      subject.message_processed(queue1) # marks queue1 to be unpaused

      expect(subject.next_queue).to eq(queue2) # implicitly unpauses queue1
      expect(subject.active_queues).to eq([[queue1, 1], [queue2, 1]])
    end

    it 'preserves weight of queues when unpausing' do
      queues << queue1
      queues << queue1
      queues << queue2

      expect(subject.next_queue).to eq(queue1)
      subject.messages_found(queue1, 1)

      expect(subject.next_queue).to eq(queue2)
      subject.messages_found(queue2, 0) # pauses queue2

      expect(subject.active_queues).to eq([[queue1, 2]])
      subject.message_processed(queue2) # marks queue2 to be unpaused

      expect(subject.next_queue).to eq(queue1) # implicitly unpauses queue2
      expect(subject.active_queues).to eq([[queue1, 2], [queue2, 1]])
    end
  end
end