Add support for deleting old versions

resources/sql/queries.sql

@@ -72,6 +72,20 @@ VALUES (:comment, :document_id, :content, :user)
 -- :doc Delete a version.
 DELETE FROM documents_version WHERE id = :id
 
+-- :name delete-old-versions :! :n
+-- :doc Delete all but the latest versions for given `document_id`.
+-- FIXME: really this should be DELETE FROM documents_version WHERE document_id = :document_id AND id NOT IN (SELECT id FROM documents_version WHERE document_id = :document_id ORDER BY created_at desc LIMIT 1)
+-- but this is apparently not supported yet by the version of mariadb that we have
+DELETE FROM documents_version
+WHERE document_id = :document_id
+AND id <> (
+    SELECT * FROM (
+    	   SELECT id FROM documents_version
+	   WHERE document_id = :document_id
+	   ORDER BY created_at DESC
+	   LIMIT 1)
+    AS dt)
+
 ------------
 -- Images --
 ------------

src/clj/daisyproducer2/documents/versions.clj

@@ -87,6 +87,22 @@
       deletions)
     0)) ;; since we could not find the version we'll return zero deletions
 
+(defn delete-old-versions
+  "Delete all but the latest version given a `document-id`. Return the number of rows affected."
+  [document-id]
+  ;; we need to fetch the versions first to know the path to the xml file, which we
+  ;; will have to delete also
+  (let [old-versions (rest (db/get-versions {:document_id document-id}))]
+    (if (seq old-versions)
+      (do
+        (doseq [old-version old-versions]
+          (when-not (fs/delete-if-exists (version-path old-version))
+            ;; if an version file does not exist we simply log that fact, but do
+            ;; not raise an exception
+            (log/errorf "Attempting to delete non-existing version file %s" (version-path old-version))))
+        (db/delete-old-versions {:document_id document-id}))
+      0)))
+
 (prometheus/instrument! metrics/registry #'get-versions)
 (prometheus/instrument! metrics/registry #'get-version)
 (prometheus/instrument! metrics/registry #'get-latest)

src/clj/daisyproducer2/routes/services.clj

@@ -334,7 +334,15 @@
                                    message (ex-message e)]
                                (log/warn message error-id errors)
                                (bad-request {:status-text (ex-message e) :errors errors})))
-                           ))}}]
+                           ))}
+       :delete {:summary "Delete all but the latest versions of a given document"
+                :middleware [wrap-restricted]
+                :swagger {:security [{:apiAuth []}]}
+                :parameters {:path {:id int?}}
+                :handler (fn [{{{:keys [id]} :path} :parameters
+                               {{uid :uid} :user} :identity}]
+                           (let [deleted (versions/delete-old-versions id)]
+                             (ok {:deleted deleted})))}}]
 
      ["/:version-id"
       [""

test/rest-api.http

@@ -157,6 +157,10 @@ Authorization: :auth-token
 DELETE http://localhost:3000/api/documents/105/versions/8449
 Authorization: :auth-token
 
+# Delete old versions
+DELETE http://localhost:3000/api/documents/105/versions
+Authorization: :auth-token
+
 ##########
 # Images #
 ##########