perf: idempotent bulk update for custom fields on migrate

Replace per-field delete+create loop (which forced ALTER TABLE on all 222
custom fields every migrate) with idempotent bulk update that only writes
when a field's definition actually changed. Saves with ignore_version=True
to bypass the Frappe Version diff bug that crashes on certain int values.

Also remove the top-level create_custom_fields() call so the function only
runs from after_migrate, not on every module import.

Optional JEY_ERP_FORCE_RECREATE_FIELDS=1 env var preserves the old
delete+create path for development.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

jey_erp/custom_fields.py

@@ -1,5 +1,64 @@
+import os
+
 import frappe
-from frappe.custom.doctype.custom_field.custom_field import create_custom_field
+from frappe.custom.doctype.custom_field.custom_field import (
+    create_custom_field,
+    get_existing_custom_fields,
+)
+
+
+def _apply_custom_fields(custom_fields: dict, ignore_validate: bool = False) -> None:
+    """Idempotent bulk create/update for Custom Fields.
+
+    Reimplements frappe.custom...create_custom_fields with two differences:
+    - saves with ignore_version=True to skip Frappe's version diff (which has
+      a bug formatting some int values for Custom Field), and
+    - calls frappe.db.updatedb() once per affected doctype, only when needed.
+    """
+    try:
+        frappe.flags.in_create_custom_fields = True
+        existing = get_existing_custom_fields(custom_fields)
+        doctypes_to_update = set()
+
+        for doctype, fields in custom_fields.items():
+            updated = False
+            for df in fields:
+                key = (doctype, df["fieldname"])
+                field = existing.get(key)
+
+                if not field:
+                    try:
+                        df = df.copy()
+                        df["owner"] = "Administrator"
+                        cf = create_custom_field(doctype, df, ignore_validate=ignore_validate)
+                        if cf:
+                            existing[key] = cf.__dict__
+                            updated = True
+                    except frappe.exceptions.DuplicateEntryError:
+                        pass
+                    continue
+
+                cf = frappe.get_doc({"doctype": "Custom Field", **field})
+                original = cf.__dict__.copy()
+                cf.update(df)
+                if original == cf.__dict__:
+                    continue
+
+                cf.flags.ignore_validate = ignore_validate
+                # ignore_version must be passed as kwarg: _save() overwrites
+                # self.flags.ignore_version from this argument on every call.
+                cf.save(ignore_version=True)
+                existing[key] = cf.__dict__
+                updated = True
+
+            if updated:
+                doctypes_to_update.add(doctype)
+
+        for doctype in doctypes_to_update:
+            frappe.clear_cache(doctype=doctype)
+            frappe.db.updatedb(doctype)
+    finally:
+        frappe.flags.in_create_custom_fields = False
 
 def create_custom_fields():
     custom_fields = {
@@ -1860,29 +1919,42 @@ def create_custom_fields():
         except Exception as e:
             print(f"Failed to delete legacy Cyrillic field: {e}")
 
+    # Filter out malformed entries (no fieldname) before passing to Frappe
+    sanitized = {}
     for doctype, fields in custom_fields.items():
+        clean = []
         for field in fields:
-            # Проверяем наличие fieldname перед обработкой
             if 'fieldname' not in field:
                 print(f"Skipping field without fieldname in {doctype}: {field}")
                 continue
-            
-            # Удаление существующего поля, если оно уже есть
-            if frappe.db.exists("Custom Field", {"dt": doctype, "fieldname": field['fieldname']}):
-                try:
-                    custom_field_name = frappe.db.get_value("Custom Field", {"dt": doctype, "fieldname": field['fieldname']}, "name")
-                    frappe.delete_doc("Custom Field", custom_field_name)
-                    frappe.db.commit()
-                    print(f"Deleted field {field['fieldname']} in {doctype}")
-                except Exception as e:
-                    print(f"Failed to delete field {field['fieldname']} in {doctype}: {e}")
+            clean.append(field)
+        if clean:
+            sanitized[doctype] = clean
 
-            # Создание нового поля
-            try:
-                create_custom_field(doctype, field)
-                print(f"Created field {field['fieldname']} in {doctype}")
-            except Exception as e:
-                print(f"Failed to create field {field['fieldname']} in {doctype}: {e}")
+    # Force-recreate mode for development: drop existing fields so Frappe
+    # creates them from scratch. Slow — only use when bulk update is not
+    # picking up something. Trigger via: JEY_ERP_FORCE_RECREATE_FIELDS=1 bench migrate
+    if os.environ.get("JEY_ERP_FORCE_RECREATE_FIELDS"):
+        for doctype, fields in sanitized.items():
+            for field in fields:
+                cf_name = frappe.db.get_value(
+                    "Custom Field",
+                    {"dt": doctype, "fieldname": field['fieldname']},
+                    "name",
+                )
+                if cf_name:
+                    try:
+                        frappe.delete_doc("Custom Field", cf_name)
+                    except Exception as e:
+                        print(f"Failed to delete field {field['fieldname']} in {doctype}: {e}")
+        frappe.db.commit()
+
+    # Idempotent bulk create/update. Mirrors frappe.custom...create_custom_fields
+    # but saves with ignore_version=True. Why: Custom Field has track_changes=1,
+    # and Frappe's diff formatter (version.get_diff → format_value) crashes on
+    # certain int values with "expected string or bytes-like object, got 'int'".
+    # We don't need version history for system-managed fields anyway.
+    _apply_custom_fields(sanitized, ignore_validate=True)
 
     # === Sub-tab wiring for Salary Slip via custom_subtabs ===
     # The custom_subtabs app reads `js_parent_subtab` on Tab Break fields in meta.
@@ -1929,6 +2001,4 @@ def create_custom_fields():
 
     # Коммит всех изменений
     frappe.db.commit()
-    print("Setting up VAT calculation hooks...")
-
-create_custom_fields()
+    print("Setting up VAT calculation hooks...")