```ruby
class LandingController < ApplicationController
  SHORT_UUID_V4_REGEXP = /\A[0-9a-f]{7}\z/i

  def index
    index_key = if Rails.env.development?
                  "basechurch:index:__development__"
                elsif fetch_revision
                  "basechurch:index:#{fetch_revision}"
                else
                  Sidekiq.redis do |r|
                    "basechurch:index:#{r.get("basechurch:index:current")}"
                  end
                end
    index = Sidekiq.redis { |r| r.get(index_key) }
    render text: process_index(index), layout: false
  end

  private

  def fetch_revision
    rev = params[:revision]
    if rev =~ SHORT_UUID_V4_REGEXP
      rev
    end
  end

  def process_index(index)
    return "INDEX_NOT_FOUND" unless index

    index.sub!(/CSRF_TOKEN/, form_authenticity_token)

    if Rails.env.development?
      index.sub!("/ember-cli-live-reload",
                 "http://localhost:4200/ember-cli-live-reload")
    end
  end
end
```

Return index after patching it
user
```ruby
class LandingController < ApplicationController
  SHORT_UUID_V4_REGEXP = /\A[0-9a-f]{7}\z/i

  def index
    index_key = if Rails.env.development?
                  "basechurch:index:__development__"
                elsif fetch_revision
                  "basechurch:index:#{fetch_revision}"
                else
                  Sidekiq.redis do |r|
                    "basechurch:index:#{r.get("basechurch:index:current")}"
                  end
                end
    index = Sidekiq.redis { |r| r.get(index_key) }
    render text: process_index(index), layout: false
  end

  private

  def fetch_revision
    rev = params[:revision]
    if rev =~ SHORT_UUID_V4_REGEXP
      rev
    end
  end

  def process_index(index)
    return "INDEX_NOT_FOUND" unless index

    index.sub!(/CSRF_TOKEN/, form_authenticity_token)

    if Rails.env.development?
      index.sub!("/ember-cli-live-reload",
                 "http://localhost:4200/ember-cli-live-reload")
    end

    index
  end
end
```
assistant