Change algorithm of follow recommendations (#28314)

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

app/models/account_suggestions/similar_profiles_source.rb

@@ -0,0 +1,67 @@
+# frozen_string_literal: true
+
+class AccountSuggestions::SimilarProfilesSource < AccountSuggestions::Source
+  class QueryBuilder < AccountSearchService::QueryBuilder
+    def must_clauses
+      [
+        {
+          more_like_this: {
+            fields: %w(text text.stemmed),
+            like: @query.map { |id| { _index: 'accounts', _id: id } },
+          },
+        },
+
+        {
+          term: {
+            properties: 'discoverable',
+          },
+        },
+      ]
+    end
+
+    def must_not_clauses
+      [
+        {
+          terms: {
+            id: following_ids,
+          },
+        },
+
+        {
+          term: {
+            properties: 'bot',
+          },
+        },
+      ]
+    end
+
+    def should_clauses
+      {
+        term: {
+          properties: {
+            value: 'verified',
+            boost: 2,
+          },
+        },
+      }
+    end
+  end
+
+  def get(account, limit: 10)
+    recently_followed_account_ids = account.active_relationships.recent.limit(5).pluck(:target_account_id)
+
+    if Chewy.enabled? && !recently_followed_account_ids.empty?
+      QueryBuilder.new(recently_followed_account_ids, account).build.limit(limit).hits.pluck('_id').map(&:to_i).zip([key].cycle)
+    else
+      []
+    end
+  rescue Faraday::ConnectionFailed
+    []
+  end
+
+  private
+
+  def key
+    :similar_to_recently_followed
+  end
+end