# frozen_string_literal: true

require 'spec_helper'

RSpec.describe Gitlab::RackAttack, :aggregate_failures, feature_category: :rate_limiting do
  describe '.configure' do
    let(:fake_rack_attack) { class_double("Rack::Attack") }
    let(:fake_rack_attack_request) { class_double(Rack::Attack::Request) }
    let(:fake_cache) { instance_double(Rack::Attack::Cache) }

    let(:throttles) do
      {
        throttle_unauthenticated_api: Gitlab::Throttle.options(:api, authenticated: false),
        throttle_authenticated_api: Gitlab::Throttle.options(:api, authenticated: true),
        throttle_unauthenticated_web: Gitlab::Throttle.unauthenticated_web_options,
        throttle_authenticated_web: Gitlab::Throttle.authenticated_web_options,
        throttle_product_analytics_collector: { limit: 100, period: 60 },
        throttle_unauthenticated_protected_paths: Gitlab::Throttle.protected_paths_options,
        throttle_authenticated_protected_paths_api: Gitlab::Throttle.protected_paths_options,
        throttle_authenticated_protected_paths_web: Gitlab::Throttle.protected_paths_options,
        throttle_unauthenticated_packages_api: Gitlab::Throttle.options(:packages_api, authenticated: false),
        throttle_authenticated_packages_api: Gitlab::Throttle.options(:packages_api, authenticated: true),
        throttle_authenticated_git_lfs: Gitlab::Throttle.throttle_authenticated_git_lfs_options,
        throttle_unauthenticated_files_api: Gitlab::Throttle.options(:files_api, authenticated: false),
        throttle_authenticated_files_api: Gitlab::Throttle.options(:files_api, authenticated: true),
        throttle_authenticated_git_http: Gitlab::Throttle.throttle_authenticated_git_http_options
      }
    end

    before do
      allow(fake_rack_attack).to receive(:throttled_responder=)
      allow(fake_rack_attack).to receive(:throttle)
      allow(fake_rack_attack).to receive(:track)
      allow(fake_rack_attack).to receive(:safelist)
      allow(fake_rack_attack).to receive(:blocklist)
      allow(fake_rack_attack).to receive(:cache).and_return(fake_cache)
      allow(fake_cache).to receive(:store=)

      fake_rack_attack.const_set(:Request, fake_rack_attack_request)
      stub_const("Rack::Attack", fake_rack_attack)
    end

    it 'extends the request class' do
      described_class.configure(fake_rack_attack)

      expect(fake_rack_attack_request).to include(described_class::Request)
    end

    it 'configures the throttle response' do
      described_class.configure(fake_rack_attack)

      expect(fake_rack_attack).to have_received(:throttled_responder=).with(an_instance_of(Proc))
    end

    it 'configures the safelist' do
      described_class.configure(fake_rack_attack)

      expect(fake_rack_attack).to have_received(:safelist).with('throttle_bypass_header')
    end

    it 'configures throttles if no dry-run was configured' do
      described_class.configure(fake_rack_attack)

      throttles.each do |throttle, options|
        expect(fake_rack_attack).to have_received(:throttle).with(throttle.to_s, options)
      end
    end

    it 'configures tracks if dry-run was configured for all throttles' do
      stub_env('GITLAB_THROTTLE_DRY_RUN', '*')

      described_class.configure(fake_rack_attack)

      throttles.each do |throttle, options|
        expect(fake_rack_attack).to have_received(:track).with(throttle.to_s, options)
      end
      expect(fake_rack_attack).not_to have_received(:throttle)
    end

    it 'configures tracks and throttles with a selected set of dry-runs' do
      dry_run_throttles = throttles.each_key.first(2)
      regular_throttles = throttles.keys[2..]
      stub_env('GITLAB_THROTTLE_DRY_RUN', dry_run_throttles.join(','))

      described_class.configure(fake_rack_attack)

      dry_run_throttles.each do |throttle|
        expect(fake_rack_attack).to have_received(:track).with(throttle.to_s, throttles[throttle])
      end
      regular_throttles.each do |throttle|
        expect(fake_rack_attack).to have_received(:throttle).with(throttle.to_s, throttles[throttle])
      end
    end

    it 'enables dry-runs for `throttle_unauthenticated_api` and `throttle_unauthenticated_web` when selecting `throttle_unauthenticated`' do
      stub_env('GITLAB_THROTTLE_DRY_RUN', 'throttle_unauthenticated')

      described_class.configure(fake_rack_attack)

      expect(fake_rack_attack).to have_received(:track).with('throttle_unauthenticated_api', throttles[:throttle_unauthenticated_api])
      expect(fake_rack_attack).to have_received(:track).with('throttle_unauthenticated_web', throttles[:throttle_unauthenticated_web])
    end

    context 'user allowlist' do
      subject { described_class.user_allowlist }

      it 'is empty' do
        described_class.configure(fake_rack_attack)

        expect(subject).to be_empty
      end

      it 'reflects GITLAB_THROTTLE_USER_ALLOWLIST' do
        stub_env('GITLAB_THROTTLE_USER_ALLOWLIST', '123,456')
        described_class.configure(fake_rack_attack)

        expect(subject).to contain_exactly(123, 456)
      end
    end
  end

  describe '.throttled_response_headers' do
    where(:matched, :match_data, :headers) do
      [
        [
          'throttle_unauthenticated',
          {
            discriminator: '127.0.0.1',
            count: 3700,
            period: 1.hour,
            limit: 3600,
            epoch_time: Time.utc(2021, 1, 5, 10, 29, 30).to_i
          },
          {
            'RateLimit-Name' => 'throttle_unauthenticated',
            'RateLimit-Limit' => '60',
            'RateLimit-Observed' => '3700',
            'RateLimit-Remaining' => '0',
            'RateLimit-Reset' => '1609844400', # Time.utc(2021, 1, 5, 11, 0, 0).to_i.to_s
            'RateLimit-ResetTime' => 'Tue, 05 Jan 2021 11:00:00 GMT',
            'Retry-After' => '1830'
          }
        ],
        [
          'throttle_unauthenticated',
          {
            discriminator: '127.0.0.1',
            count: 3700,
            period: 1.hour,
            limit: 3600,
            epoch_time: Time.utc(2021, 1, 5, 10, 59, 59).to_i
          },
          {
            'RateLimit-Name' => 'throttle_unauthenticated',
            'RateLimit-Limit' => '60',
            'RateLimit-Observed' => '3700',
            'RateLimit-Remaining' => '0',
            'RateLimit-Reset' => '1609844400', # Time.utc(2021, 1, 5, 11, 0, 0).to_i.to_s
            'RateLimit-ResetTime' => 'Tue, 05 Jan 2021 11:00:00 GMT',
            'Retry-After' => '1'
          }
        ],
        [
          'throttle_unauthenticated',
          {
            discriminator: '127.0.0.1',
            count: 3700,
            period: 1.hour,
            limit: 3600,
            epoch_time: Time.utc(2021, 1, 5, 10, 0, 0).to_i
          },
          {
            'RateLimit-Name' => 'throttle_unauthenticated',
            'RateLimit-Limit' => '60',
            'RateLimit-Observed' => '3700',
            'RateLimit-Remaining' => '0',
            'RateLimit-Reset' => '1609844400', # Time.utc(2021, 1, 5, 11, 0, 0).to_i.to_s
            'RateLimit-ResetTime' => 'Tue, 05 Jan 2021 11:00:00 GMT',
            'Retry-After' => '3600'
          }
        ],
        [
          'throttle_unauthenticated',
          {
            discriminator: '127.0.0.1',
            count: 3700,
            period: 1.hour,
            limit: 3600,
            epoch_time: Time.utc(2021, 1, 5, 23, 30, 0).to_i
          },
          {
            'RateLimit-Name' => 'throttle_unauthenticated',
            'RateLimit-Limit' => '60',
            'RateLimit-Observed' => '3700',
            'RateLimit-Remaining' => '0',
            'RateLimit-Reset' => '1609891200', # Time.utc(2021, 1, 6, 0, 0, 0).to_i.to_s
            'RateLimit-ResetTime' => 'Wed, 06 Jan 2021 00:00:00 GMT', # Next day
            'Retry-After' => '1800'
          }
        ],
        [
          'throttle_unauthenticated',
          {
            discriminator: '127.0.0.1',
            count: 3700,
            period: 1.hour,
            limit: 3400,
            epoch_time: Time.utc(2021, 1, 5, 10, 30, 0).to_i
          },
          {
            'RateLimit-Name' => 'throttle_unauthenticated',
            'RateLimit-Limit' => '57', # 56.66 requests per minute
            'RateLimit-Observed' => '3700',
            'RateLimit-Remaining' => '0',
            'RateLimit-Reset' => '1609844400', # Time.utc(2021, 1, 5, 11, 0, 0).to_i.to_s
            'RateLimit-ResetTime' => 'Tue, 05 Jan 2021 11:00:00 GMT',
            'Retry-After' => '1800'
          }
        ],
        [
          'throttle_unauthenticated',
          {
            discriminator: '127.0.0.1',
            count: 3700,
            period: 1.hour,
            limit: 3700,
            epoch_time: Time.utc(2021, 1, 5, 10, 30, 0).to_i
          },
          {
            'RateLimit-Name' => 'throttle_unauthenticated',
            'RateLimit-Limit' => '62', # 61.66 requests per minute
            'RateLimit-Observed' => '3700',
            'RateLimit-Remaining' => '0',
            'RateLimit-Reset' => '1609844400', # Time.utc(2021, 1, 5, 11, 0, 0).to_i.to_s
            'RateLimit-ResetTime' => 'Tue, 05 Jan 2021 11:00:00 GMT',
            'Retry-After' => '1800'
          }
        ],
        [
          'throttle_unauthenticated',
          {
            discriminator: '127.0.0.1',
            count: 3700,
            period: 1.hour,
            limit: 59,
            epoch_time: Time.utc(2021, 1, 5, 10, 30, 0).to_i
          },
          {
            'RateLimit-Name' => 'throttle_unauthenticated',
            'RateLimit-Limit' => '1', # 0.9833 requests per minute
            'RateLimit-Observed' => '3700',
            'RateLimit-Remaining' => '0',
            'RateLimit-Reset' => '1609844400', # Time.utc(2021, 1, 5, 11, 0, 0).to_i.to_s
            'RateLimit-ResetTime' => 'Tue, 05 Jan 2021 11:00:00 GMT',
            'Retry-After' => '1800'
          }
        ],
        [
          'throttle_unauthenticated',
          {
            discriminator: '127.0.0.1',
            count: 3700,
            period: 1.hour,
            limit: 61,
            epoch_time: Time.utc(2021, 1, 5, 10, 30, 0).to_i
          },
          {
            'RateLimit-Name' => 'throttle_unauthenticated',
            'RateLimit-Limit' => '2', # 1.016 requests per minute
            'RateLimit-Observed' => '3700',
            'RateLimit-Remaining' => '0',
            'RateLimit-Reset' => '1609844400', # Time.utc(2021, 1, 5, 11, 0, 0).to_i.to_s
            'RateLimit-ResetTime' => 'Tue, 05 Jan 2021 11:00:00 GMT',
            'Retry-After' => '1800'
          }
        ],
        [
          'throttle_unauthenticated',
          {
            discriminator: '127.0.0.1',
            count: 3700,
            period: 15.seconds,
            limit: 10,
            epoch_time: Time.utc(2021, 1, 5, 10, 30, 0).to_i
          },
          {
            'RateLimit-Name' => 'throttle_unauthenticated',
            'RateLimit-Limit' => '40',
            'RateLimit-Observed' => '3700',
            'RateLimit-Remaining' => '0',
            'RateLimit-Reset' => '1609842615', # Time.utc(2021, 1, 5, 10, 30, 15).to_i.to_s
            'RateLimit-ResetTime' => 'Tue, 05 Jan 2021 10:30:15 GMT',
            'Retry-After' => '15'
          }
        ],
        [
          'throttle_unauthenticated',
          {
            discriminator: '127.0.0.1',
            count: 3700,
            period: 27.seconds,
            limit: 10,
            epoch_time: Time.utc(2021, 1, 5, 10, 30, 0).to_i
          },
          {
            'RateLimit-Name' => 'throttle_unauthenticated',
            'RateLimit-Limit' => '23',
            'RateLimit-Observed' => '3700',
            'RateLimit-Remaining' => '0',
            'RateLimit-Reset' => '1609842627', # Time.utc(2021, 1, 5, 10, 30, 27).to_i.to_s
            'RateLimit-ResetTime' => 'Tue, 05 Jan 2021 10:30:27 GMT',
            'Retry-After' => '27'
          }
        ]
      ]
    end

    with_them do
      it 'generates accurate throttled headers' do
        expect(described_class.throttled_response_headers(matched, match_data)).to eql(headers)
      end
    end
  end
end
