From 48ba4ef7ca21db600371873d8329a4c97f7f30f4 Mon Sep 17 00:00:00 2001
From: Julian Schacher <julian.schacher@dg-i.net>
Date: Mon, 2 Dec 2024 19:46:28 +0100
Subject: [PATCH] add logic for removing deleted notes from users histories

---
 hedgedoc-expire.py | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/hedgedoc-expire.py b/hedgedoc-expire.py
index 57a2762..e4c1cba 100644
--- a/hedgedoc-expire.py
+++ b/hedgedoc-expire.py
@@ -1,5 +1,7 @@
 #!/bin/env python
 import argparse
+import base64
+import binascii
 import email
 import json
 import smtplib
@@ -219,6 +221,41 @@ class HedgedocExpire:
                     if self.config.verbose:
                         url = self.config.url + '/' + (note["alias"] if note["alias"] is not None else note["shortid"])
                         print(f'Note "{note["title"]}" ({url}) emailed to {msg["To"]}')
+
+                    try:
+                        with conn.cursor(row_factory=dict_row) as user_history_cur:
+                            # Calculate the urlid of the note from its id.
+                            # See:
+                            # - https://github.com/hedgedoc/hedgedoc/blob/380587b7fd65bc1eb71eef51a3aab324f9877650/lib/models/note.js#L167-L172
+                            # - https://git.cccv.de/infra/ansible/roles/hedgedoc/-/blob/d69cef4bf6c7fe4e67570363659e4c20b0e102af/files/hedgedoc-util.py#L84
+                            urlid = base64.urlsafe_b64encode(binascii.unhexlify(f"{note['id']}".replace('-', ''))).decode().replace('=', '')
+
+                            # Get all users with note in history.
+                            user_history_cur.execute('''SELECT
+                                                            "Users"."id",
+                                                            "Users"."history",
+                                                            "Users"."email",
+                                                            "Users"."profile"
+                                                        FROM "Users"
+                                                        WHERE jsonb_path_exists("Users"."history"::jsonb, '$[*] ? (@.id == $urlid)', jsonb_build_object('urlid', %s::text))
+                                                        ''', [urlid])
+                            users_with_note = user_history_cur.fetchall()
+
+                            for user in users_with_note:
+                                history = json.loads(user["history"])
+                                history_without_note = json.dumps([ entry for entry in history if entry["id"] != urlid ])
+                                user_history_cur.execute('''UPDATE "Users"
+                                                            SET "history" = %s
+                                                            WHERE "id" = %s
+                                                         ''', [history_without_note, user["id"]])
+                            
+                            conn.commit()
+                            if self.config.verbose:
+                                for user in users_with_note:
+                                    print(f'    deleted history entry for {self.email_from_email_or_profile(user)}')
+                    except Exception as e:
+                        conn.rollback()
+                        print(f'An error occured while trying to delete {note["id"]} from the users history: {e}', file=sys.stderr)
                 except Exception as e:
                     print(f'Unable to send email to {self.email_from_email_or_profile(note)}: {e}', file=sys.stderr)