Add pre-registration validation for IA email and username

openlibrary/i18n/messages.pot

@@ -6445,6 +6445,10 @@ msgstr ""
 msgid "Username unavailable"
 msgstr ""
 
+#: account.py
+msgid "An Internet Archive account already exists with this username"
+msgstr ""
+
 #: account.py forms.py
 msgid "Must be a valid email address"
 msgstr ""
@@ -6453,6 +6457,10 @@ msgstr ""
 msgid "Email already registered"
 msgstr ""
 
+#: account.py
+msgid "An Internet Archive account already exists with this email"
+msgstr ""
+
 #: account.py
 msgid "Email address is already used."
 msgstr ""

openlibrary/plugins/upstream/account.py

@@ -2,6 +2,7 @@
 import json
 import logging
 import re
+import requests
 from typing import Any, TYPE_CHECKING, Final
 from collections.abc import Callable
 from collections.abc import Iterable, Mapping
@@ -551,16 +552,29 @@ def GET(self):
 class account_validation(delegate.page):
     path = '/account/validate'
 
+    @staticmethod
+    def ia_username_exists(username):
+        url = "https://archive.org/metadata/@%s" % username
+        try:
+            return bool(requests.get(url).json())
+        except (OSError, ValueError):
+            return
+
     @staticmethod
     def validate_username(username):
         if not 3 <= len(username) <= 20:
             return _('Username must be between 3-20 characters')
         if not re.match('^[A-Za-z0-9-_]{3,20}$', username):
             return _('Username may only contain numbers and letters')
+
         ol_account = OpenLibraryAccount.get(username=username)
         if ol_account:
             return _("Username unavailable")
 
+        ia_account = account_validation.ia_username_exists(username)
+        if ia_account:
+            return _("An Internet Archive account already exists with this username")
+
     @staticmethod
     def validate_email(email):
         if not (email and re.match(r'.*@.*\..*', email)):
@@ -570,6 +584,10 @@ def validate_email(email):
         if ol_account:
             return _('Email already registered')
 
+        ia_account = InternetArchiveAccount.get(email=email)
+        if ia_account:
+            return _('An Internet Archive account already exists with this email')
+
     def GET(self):
         i = web.input()
         errors = {'email': None, 'username': None}