Add cache for OEmbed endpoints to avoid extra HTTP requests (#12403)

* add youtube oembed endpoint

* add check for oembed endpoint

* change unless for a more readable if

* clear blank lines

* endpoint via https

* Fix string literal in condition

* use cache for endpoints

* use cache for endpoints

* clean up and adding check

* clean up and remove redundant return

* add html check

* add false to return

* use double quotes

* use double quotes

* Clean up

app/services/fetch_oembed_service.rb

@@ -1,13 +1,20 @@
 # frozen_string_literal: true
 
 class FetchOEmbedService
+  ENDPOINT_CACHE_EXPIRES_IN = 24.hours.freeze
+
   attr_reader :url, :options, :format, :endpoint_url
 
   def call(url, options = {})
     @url     = url
     @options = options
 
-    discover_endpoint!
+    if @options[:cached_endpoint]
+      parse_cached_endpoint!
+    else
+      discover_endpoint!
+    end
+
     fetch!
   end
 
@@ -32,10 +39,32 @@ class FetchOEmbedService
     return if @endpoint_url.blank?
 
     @endpoint_url = (Addressable::URI.parse(@url) + @endpoint_url).to_s
+
+    cache_endpoint!
   rescue Addressable::URI::InvalidURIError
     @endpoint_url = nil
   end
 
+  def parse_cached_endpoint!
+    cached = @options[:cached_endpoint]
+
+    return if cached[:endpoint].nil? || cached[:format].nil?
+
+    @endpoint_url = Addressable::Template.new(cached[:endpoint]).expand(url: @url).to_s
+    @format       = cached[:format]
+  end
+
+  def cache_endpoint!
+    url_domain = Addressable::URI.parse(@url).normalized_host
+
+    endpoint_hash = {
+      endpoint: @endpoint_url.gsub(URI.encode_www_form_component(@url), '{url}'),
+      format: @format,
+    }
+
+    Rails.cache.write("oembed_endpoint:#{url_domain}", endpoint_hash, expires_in: ENDPOINT_CACHE_EXPIRES_IN)
+  end
+
   def fetch!
     return if @endpoint_url.blank?