Add GET /api/v1/donation_campaigns (#37880)

app/controllers/api/v1/donation_campaigns_controller.rb

@@ -0,0 +1,86 @@
+# frozen_string_literal: true
+
+class Api::V1::DonationCampaignsController < Api::BaseController
+  before_action :require_user!
+
+  STOPLIGHT_COOL_OFF_TIME = 60
+  STOPLIGHT_FAILURE_THRESHOLD = 10
+
+  def index
+    return head 204 if api_url.blank?
+
+    json = from_cache
+    return render json: json if json.present?
+
+    campaign = fetch_campaign
+    return head 204 if campaign.nil?
+
+    save_to_cache!(campaign)
+
+    render json: campaign
+  end
+
+  private
+
+  def api_url
+    Rails.configuration.x.donation_campaigns.api_url
+  end
+
+  def seed
+    @seed ||= Random.new(current_account.id).rand(100)
+  end
+
+  def from_cache
+    key = Rails.cache.read(request_key, raw: true)
+    return if key.blank?
+
+    campaign = Rails.cache.read("donation_campaign:#{key}", raw: true)
+    Oj.load(campaign) if campaign.present?
+  end
+
+  def save_to_cache!(campaign)
+    return if campaign.blank?
+
+    Rails.cache.write_multi(
+      {
+        request_key => campaign_key(campaign),
+        "donation_campaign:#{campaign_key(campaign)}" => Oj.dump(campaign),
+      },
+      expires_in: 1.hour,
+      raw: true
+    )
+  end
+
+  def fetch_campaign
+    stoplight_wrapper.run do
+      url = Addressable::URI.parse(api_url)
+      url.query_values = { platform: 'web', seed: seed, locale: locale, environment: Rails.configuration.x.donation_campaigns.environment }.compact
+
+      Request.new(:get, url.to_s).perform do |res|
+        return Oj.load(res.body_with_limit, mode: :strict) if res.code == 200
+      end
+    end
+  rescue *Mastodon::HTTP_CONNECTION_ERRORS, Oj::ParseError
+    nil
+  end
+
+  def stoplight_wrapper
+    Stoplight(
+      'donation_campaigns',
+      cool_off_time: STOPLIGHT_COOL_OFF_TIME,
+      threshold: STOPLIGHT_FAILURE_THRESHOLD
+    )
+  end
+
+  def request_key
+    "donation_campaign_request:#{seed}:#{locale}"
+  end
+
+  def campaign_key(campaign)
+    "#{campaign['id']}:#{campaign['locale']}"
+  end
+
+  def locale
+    I18n.locale.to_s
+  end
+end

config/mastodon.yml

@@ -4,6 +4,9 @@ shared:
   limited_federation_mode: <%= (ENV.fetch('LIMITED_FEDERATION_MODE', nil) || ENV.fetch('WHITELIST_MODE', nil)) == 'true' %>
   self_destruct_value: <%= ENV.fetch('SELF_DESTRUCT', nil)&.to_json %>
   software_update_url: <%= ENV.fetch('UPDATE_CHECK_URL', 'https://api.joinmastodon.org/update-check')&.to_json %>
+  donation_campaigns:
+    api_url: <%= ENV.fetch('DONATION_CAMPAIGNS_URL', nil)&.to_json %>
+    environment: <%= ENV.fetch('DONATION_CAMPAIGNS_ENVIRONMENT', nil)&.to_json %>
   source:
     base_url: <%= ENV.fetch('SOURCE_BASE_URL', nil)&.to_json %>
     repository: <%= ENV.fetch('GITHUB_REPOSITORY', 'mastodon/mastodon') %>

config/routes/api.rb

@@ -74,6 +74,7 @@ namespace :api, format: false do
     resources :suggestions, only: [:index, :destroy]
     resources :scheduled_statuses, only: [:index, :show, :update, :destroy]
     resources :preferences, only: [:index]
+    resources :donation_campaigns, only: [:index]
 
     resources :annual_reports, only: [:index, :show] do
       member do

spec/requests/api/v1/donation_campaigns_spec.rb

@@ -0,0 +1,105 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe 'Donation campaigns' do
+  include_context 'with API authentication'
+
+  describe 'GET /api/v1/donation_campaigns' do
+    context 'when not authenticated' do
+      it 'returns http unprocessable entity' do
+        get '/api/v1/donation_campaigns'
+
+        expect(response)
+          .to have_http_status(422)
+        expect(response.content_type)
+          .to start_with('application/json')
+      end
+    end
+
+    context 'when no donation campaign API is set up' do
+      it 'returns http empty' do
+        get '/api/v1/donation_campaigns', headers: headers
+
+        expect(response)
+          .to have_http_status(204)
+      end
+    end
+
+    context 'when a donation campaign API is set up' do
+      let(:api_url) { 'https://example.org/donations' }
+      let(:seed) { Random.new(user.account_id).rand(100) }
+
+      around do |example|
+        original = Rails.configuration.x.donation_campaigns.api_url
+        Rails.configuration.x.donation_campaigns.api_url = api_url
+
+        example.run
+
+        Rails.configuration.x.donation_campaigns.api_url = original
+      end
+
+      context 'when the donation campaign API does not return a campaign' do
+        before do
+          stub_request(:get, "#{api_url}?platform=web&seed=#{seed}&locale=en").to_return(status: 204)
+        end
+
+        it 'returns http empty' do
+          get '/api/v1/donation_campaigns', headers: headers
+
+          expect(response)
+            .to have_http_status(204)
+        end
+      end
+
+      context 'when the donation campaign API returns a campaign' do
+        let(:campaign_json) do
+          {
+            'id' => 'campaign-1',
+            'banner_message' => 'Hi',
+            'banner_button_text' => 'Donate!',
+            'donation_message' => 'Hi!',
+            'donation_button_text' => 'Money',
+            'donation_success_post' => 'Success post',
+            'amounts' => {
+              'one_time' => {
+                'EUR' => [1, 2, 3],
+                'USD' => [4, 5, 6],
+              },
+              'monthly' => {
+                'EUR' => [1],
+                'USD' => [2],
+              },
+            },
+            'default_currency' => 'EUR',
+            'donation_url' => 'https://sponsor.joinmastodon.org/donate/new',
+            'locale' => 'en',
+          }
+        end
+
+        before do
+          stub_request(:get, "#{api_url}?platform=web&seed=#{seed}&locale=en").to_return(body: Oj.dump(campaign_json), status: 200)
+        end
+
+        it 'returns the expected campaign' do
+          get '/api/v1/donation_campaigns', headers: headers
+
+          expect(response)
+            .to have_http_status(200)
+
+          expect(response.content_type)
+            .to start_with('application/json')
+
+          expect(response.parsed_body)
+            .to match(campaign_json)
+
+          expect(Rails.cache.read("donation_campaign_request:#{seed}:en", raw: true))
+            .to eq 'campaign-1:en'
+
+          expect(Oj.load(Rails.cache.read('donation_campaign:campaign-1:en', raw: true)))
+            .to match(campaign_json)
+        end
+      end
+    end
+  end
+end