Feature: Implement account deletion (#248)

* Add backend code for user deletion

* Add endpoint and delete user test

* Delete all user content from db

* Delete from playlist_videos table on user deletion

* Avoid raw SQL in unsubscribeResponse()

* Fix unsubscribeResponse()

* Don't delete PlaylistVideos from other users' playlists

* Fix pruneUnusedPlaylistVideos()

* Remove unused commented-out code

* Fix oopsie

* Proper type declaration due to false error-reporting by VSCode

* Use delete query for better performance

* Cleanup and add OneToMany relationship.

* Revert unsubscribe logic.

Co-authored-by: Kavin <20838718+FireMasterK@users.noreply.github.com>

src/main/java/me/kavin/piped/ServerLauncher.java

@@ -14,6 +14,7 @@ import io.activej.inject.module.Module;
 import io.activej.launchers.http.MultithreadedHttpServerLauncher;
 import me.kavin.piped.consts.Constants;
 import me.kavin.piped.utils.*;
+import me.kavin.piped.utils.resp.DeleteUserRequest;
 import me.kavin.piped.utils.resp.ErrorResponse;
 import me.kavin.piped.utils.resp.LoginRequest;
 import me.kavin.piped.utils.resp.SubscriptionUpdateRequest;
@@ -327,6 +328,15 @@ public class ServerLauncher extends MultithreadedHttpServerLauncher {
                     } catch (Exception e) {
                         return getErrorResponse(e, request.getPath());
                     }
+                })).map(POST, "/user/delete", AsyncServlet.ofBlocking(executor, request -> {
+                    try {
+                        DeleteUserRequest body = Constants.mapper.readValue(request.loadBody().getResult().asArray(), 
+                            DeleteUserRequest.class);
+                        return getJsonResponse(ResponseHelper.deleteUserResponse(request.getHeader(AUTHORIZATION), body.password),
+                                "private");
+                    } catch (Exception e) {
+                        return getErrorResponse(e, request.getPath());
+                    }
                 }));
 
         return new CustomServletDecorator(router);

src/main/java/me/kavin/piped/utils/DatabaseHelper.java

@@ -16,15 +16,19 @@ public class DatabaseHelper {
     public static User getUserFromSession(String session) {
         try (Session s = DatabaseSessionFactory.createSession()) {
             s.setHibernateFlushMode(FlushMode.MANUAL);
-            CriteriaBuilder cb = s.getCriteriaBuilder();
-            CriteriaQuery<User> cr = cb.createQuery(User.class);
-            Root<User> root = cr.from(User.class);
-            cr.select(root).where(cb.equal(root.get("sessionId"), session));
-
-            return s.createQuery(cr).uniqueResult();
+            return getUserFromSession(session, s);
         }
     }
 
+    public static User getUserFromSession(String session, Session s) {
+        CriteriaBuilder cb = s.getCriteriaBuilder();
+        CriteriaQuery<User> cr = cb.createQuery(User.class);
+        Root<User> root = cr.from(User.class);
+        cr.select(root).where(cb.equal(root.get("sessionId"), session));
+
+        return s.createQuery(cr).uniqueResult();
+    }
+
     public static User getUserFromSessionWithSubscribed(String session) {
         try (Session s = DatabaseSessionFactory.createSession()) {
             s.setHibernateFlushMode(FlushMode.MANUAL);

src/main/java/me/kavin/piped/utils/ResponseHelper.java

@@ -622,8 +622,6 @@ public class ResponseHelper {
 
     }
 
-    private static final Argon2PasswordEncoder argon2PasswordEncoder = new Argon2PasswordEncoder();
-
     public static byte[] registerResponse(String user, String pass) throws IOException {
 
         if (Constants.DISABLE_REGISTRATION)
@@ -641,9 +639,8 @@ public class ResponseHelper {
             cr.select(root).where(cb.equal(root.get("username"), user));
             boolean registered = s.createQuery(cr).uniqueResult() != null;
 
-            if (registered) {
+            if (registered)
                 return Constants.mapper.writeValueAsBytes(new AlreadyRegisteredResponse());
-            }
 
             if (Constants.COMPROMISED_PASSWORD_CHECK) {
                 String sha1Hash = DigestUtils.sha1Hex(pass).toUpperCase();
@@ -668,8 +665,16 @@ public class ResponseHelper {
         }
     }
 
+    private static final Argon2PasswordEncoder argon2PasswordEncoder = new Argon2PasswordEncoder();
+
     private static final BCryptPasswordEncoder bcryptPasswordEncoder = new BCryptPasswordEncoder();
 
+    private static boolean hashMatch(String hash, String pass) {
+        return hash.startsWith("$argon2") ?
+                argon2PasswordEncoder.matches(pass, hash) :
+                bcryptPasswordEncoder.matches(pass, hash);
+    }
+
     public static byte[] loginResponse(String user, String pass)
             throws IOException {
 
@@ -688,11 +693,7 @@ public class ResponseHelper {
 
             if (dbuser != null) {
                 String hash = dbuser.getPassword();
-                if (hash.startsWith("$argon2")) {
-                    if (argon2PasswordEncoder.matches(pass, hash)) {
-                        return Constants.mapper.writeValueAsBytes(new LoginResponse(dbuser.getSessionId()));
-                    }
-                } else if (bcryptPasswordEncoder.matches(pass, hash)) {
+                if (hashMatch(hash, pass)) {
                     return Constants.mapper.writeValueAsBytes(new LoginResponse(dbuser.getSessionId()));
                 }
             }
@@ -701,6 +702,37 @@ public class ResponseHelper {
         }
     }
 
+    public static byte[] deleteUserResponse(String session, String pass) throws IOException {
+
+        if (StringUtils.isBlank(pass))
+            return Constants.mapper.writeValueAsBytes(new InvalidRequestResponse());
+
+        try (Session s = DatabaseSessionFactory.createSession()) {
+            User user = DatabaseHelper.getUserFromSession(session);
+
+            if (user == null)
+                return Constants.mapper.writeValueAsBytes(new AuthenticationFailureResponse());
+
+            String hash = user.getPassword();
+
+            if (!hashMatch(hash, pass))
+                return Constants.mapper.writeValueAsBytes(new IncorrectCredentialsResponse());
+
+            try {
+                s.delete(user);
+
+                s.getTransaction().begin();
+                s.getTransaction().commit();
+
+                Multithreading.runAsync(() -> pruneUnusedPlaylistVideos());
+            } catch (Exception e) {
+                return Constants.mapper.writeValueAsBytes(new ErrorResponse(ExceptionUtils.getStackTrace(e), e.getMessage()));
+            }
+
+            return Constants.mapper.writeValueAsBytes(new DeleteUserResponse(user.getUsername()));
+        }
+    }
+
     public static byte[] subscribeResponse(String session, String channelId)
             throws IOException {
 
@@ -902,6 +934,7 @@ public class ResponseHelper {
             Multithreading.runAsync(() -> {
                 try (Session s = DatabaseSessionFactory.createSession()) {
                     var channels = DatabaseHelper.getChannelsFromIds(s, Arrays.asList(channelIds));
+
                     outer:
                     for (String channelId : channelIds) {
                         for (var channel : channels)
@@ -1001,6 +1034,8 @@ public class ResponseHelper {
 
             s.getTransaction().begin();
             s.getTransaction().commit();
+
+            Multithreading.runAsync(() -> pruneUnusedPlaylistVideos());
         }
 
         return Constants.mapper.writeValueAsBytes(new AcceptedResponse());
@@ -1008,21 +1043,16 @@ public class ResponseHelper {
 
     public static byte[] playlistsResponse(String session) throws IOException {
 
-        User user = DatabaseHelper.getUserFromSession(session);
-
-        if (user == null)
-            return Constants.mapper.writeValueAsBytes(new AuthenticationFailureResponse());
-
         try (Session s = DatabaseSessionFactory.createSession()) {
-            var cb = s.getCriteriaBuilder();
-            var query = cb.createQuery(me.kavin.piped.utils.obj.db.Playlist.class);
-            var root = query.from(me.kavin.piped.utils.obj.db.Playlist.class);
-            query.select(root);
-            query.where(cb.equal(root.get("owner"), user));
+
+            User user = DatabaseHelper.getUserFromSession(session, s);
+
+            if (user == null)
+                return Constants.mapper.writeValueAsBytes(new AuthenticationFailureResponse());
 
             var playlists = new ObjectArrayList<>();
 
-            for (var playlist : s.createQuery(query).list()) {
+            for (var playlist : user.getPlaylists()) {
                 ObjectNode node = Constants.mapper.createObjectNode();
                 node.put("id", String.valueOf(playlist.getPlaylistId()));
                 node.put("name", playlist.getName());
@@ -1137,6 +1167,8 @@ public class ResponseHelper {
                 s.getTransaction().begin();
             s.getTransaction().commit();
 
+            Multithreading.runAsync(() -> pruneUnusedPlaylistVideos());
+
             return Constants.mapper.writeValueAsBytes(new AcceptedResponse());
         }
     }
@@ -1157,6 +1189,27 @@ public class ResponseHelper {
         }
     }
 
+    private static void pruneUnusedPlaylistVideos() {
+
+        try (Session s = DatabaseSessionFactory.createSession()) {
+            CriteriaBuilder cb = s.getCriteriaBuilder();
+
+            var pvQuery = cb.createCriteriaDelete(PlaylistVideo.class);
+            var pvRoot = pvQuery.from(PlaylistVideo.class);
+
+            var subQuery = pvQuery.subquery(me.kavin.piped.utils.obj.db.Playlist.class);
+            var subRoot = subQuery.from(me.kavin.piped.utils.obj.db.Playlist.class);
+
+            subQuery.select(subRoot.join("videos").get("id"));
+
+            pvQuery.where(cb.not(pvRoot.get("id").in(subQuery)));
+
+            s.getTransaction().begin();
+            s.createQuery(pvQuery).executeUpdate();
+            s.getTransaction().commit();
+        }
+    }
+
     private static void handleNewVideo(StreamInfo info, long time, me.kavin.piped.utils.obj.db.Channel channel, Session s) {
 
         if (channel == null)

src/main/java/me/kavin/piped/utils/obj/db/User.java

@@ -34,6 +34,9 @@ public class User implements Serializable {
     @Column(name = "channel", length = 30)
     private Set<String> subscribed_ids;
 
+    @OneToMany(mappedBy = "owner", cascade = CascadeType.ALL)
+    private Set<Playlist> playlists;
+
     public User() {
     }
 
@@ -83,4 +86,12 @@ public class User implements Serializable {
     public void setSubscribed(Set<String> subscribed_ids) {
         this.subscribed_ids = subscribed_ids;
     }
+
+    public Set<Playlist> getPlaylists() {
+        return playlists;
+    }
+
+    public void setPlaylists(Set<Playlist> playlists) {
+        this.playlists = playlists;
+    }
 }

src/main/java/me/kavin/piped/utils/resp/DeleteUserRequest.java

@@ -0,0 +1,7 @@
+package me.kavin.piped.utils.resp;
+
+public class DeleteUserRequest {
+   
+    public String password;
+    
+}

src/main/java/me/kavin/piped/utils/resp/DeleteUserResponse.java

@@ -0,0 +1,10 @@
+package me.kavin.piped.utils.resp;
+
+public class DeleteUserResponse {
+    
+    public String username;
+
+    public DeleteUserResponse(String username) {
+        this.username = username;
+    }
+}

testing/api-test.sh

@@ -107,3 +107,6 @@ curl ${CURLOPTS[@]} $HOST/user/playlists/remove -X POST -H "Content-Type: applic
 
 # Delete Playlist Test
 curl ${CURLOPTS[@]} $HOST/user/playlists/delete -X POST -H "Content-Type: application/json" -H "Authorization: $AUTH_TOKEN" -d $(jq -n --compact-output --arg playlistId $PLAYLIST_ID '{"playlistId": $playlistId}') || exit 1
+
+# Delete User Test
+curl ${CURLOPTS[@]} $HOST/user/delete -X POST -H "Content-Type: application/json" -H "Authorization: $AUTH_TOKEN" -d $(jq -n --compact-output --arg password "$PASS" '{"password": $password}') || exit 1