From ba6d0ef9db31e528b1c6a520b7f9d2c1bc4c856b Mon Sep 17 00:00:00 2001
From: Georges-Antoine Assi <contact@me.gantoine.com>
Date: Thu, 25 Jun 2026 19:17:26 -0400
Subject: [PATCH] cleanup

---
 .../versions/0091_unique_platform_fs_name.py  | 18 ++---------------
 backend/endpoints/roms/__init__.py            | 20 +++++++++----------
 backend/endpoints/sockets/scan.py             |  4 +---
 backend/models/rom.py                         |  4 +---
 4 files changed, 13 insertions(+), 33 deletions(-)

diff --git a/backend/alembic/versions/0091_unique_platform_fs_name.py b/backend/alembic/versions/0091_unique_platform_fs_name.py
index 75d9372d1..e2f320471 100644
--- a/backend/alembic/versions/0091_unique_platform_fs_name.py
+++ b/backend/alembic/versions/0091_unique_platform_fs_name.py
@@ -1,11 +1,5 @@
 """Enforce unique (platform_id, fs_name) on roms
 
-A platform folder can't physically hold two entries with the same name, so a
-ROM is uniquely identified by (platform_id, fs_name). The index covering this
-pair was non-unique, which let two concurrent scans (e.g. the manual scan the
-patcher fires after uploading a patched ROM, racing a filesystem-watcher or
-scheduled scan) both insert the same ROM, producing duplicate library entries.
-
 This migration removes any pre-existing duplicates (keeping the lowest id) and
 upgrades the index to unique so the duplicate can never be created again.
 
@@ -32,13 +26,7 @@ def upgrade() -> None:
     connection = op.get_bind()
 
     # Drop duplicate roms sharing (platform_id, fs_name), keeping the lowest id.
-    # The nested derived table is required so MySQL/MariaDB don't reject reading
-    # the same table being deleted from; it's a valid no-op on PostgreSQL too.
-    # Dependent rows (files, user props, assets, collections, ...) are removed by
-    # their ON DELETE CASCADE foreign keys.
-    connection.execute(
-        sa.text(
-            """
+    connection.execute(sa.text("""
             DELETE FROM roms
             WHERE id NOT IN (
                 SELECT keep_id FROM (
@@ -47,9 +35,7 @@ def upgrade() -> None:
                     GROUP BY platform_id, fs_name
                 ) AS keepers
             )
-            """
-        )
-    )
+            """))
 
     with op.batch_alter_table("roms", schema=None) as batch_op:
         batch_op.drop_index(INDEX_NAME, if_exists=True)
diff --git a/backend/endpoints/roms/__init__.py b/backend/endpoints/roms/__init__.py
index 9c73e9e7c..677efcd2d 100644
--- a/backend/endpoints/roms/__init__.py
+++ b/backend/endpoints/roms/__init__.py
@@ -28,6 +28,7 @@ from fastapi.responses import Response
 from fastapi_pagination import resolve_params
 from fastapi_pagination.limit_offset import LimitOffsetPage, LimitOffsetParams
 from pydantic import BaseModel, Field
+from sqlalchemy.exc import IntegrityError
 from starlette.responses import FileResponse
 
 from config import (
@@ -1484,16 +1485,6 @@ async def update_rom(
     # Re-parse tags from the filename so region/language/revision/version/tags
     # stay in sync whenever the fs_name changes.
     if new_fs_name != rom.fs_name:
-        # (platform_id, fs_name) is unique, so reject a rename that would collide
-        # with another ROM on this platform before the DB update would fail.
-        if db_rom_handler.get_roms_by_fs_name(
-            platform_id=rom.platform_id, fs_names={new_fs_name}
-        ):
-            raise HTTPException(
-                status_code=status.HTTP_409_CONFLICT,
-                detail=f"A ROM named '{new_fs_name}' already exists on this platform",
-            )
-
         parsed_tags = fs_rom_handler.parse_tags(new_fs_name)
         cleaned_data.update(
             {
@@ -1608,7 +1599,14 @@ async def update_rom(
         f"Updating {hl(cleaned_data.get('name', ''), color=BLUE)} [{hl(cleaned_data.get('fs_name', ''))}] with data {cleaned_data}"
     )
 
-    db_rom_handler.update_rom(id, cleaned_data)
+    try:
+        db_rom_handler.update_rom(id, cleaned_data)
+    except IntegrityError as exc:
+        log.error(f"Failed to update ROM {id}: {exc}")
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail=f"Failed to update ROM {id}: {exc}",
+        ) from exc
 
     # Rename the file/folder if the name has changed
     should_update_fs = new_fs_name != rom.fs_name
diff --git a/backend/endpoints/sockets/scan.py b/backend/endpoints/sockets/scan.py
index 312b7b8da..9ccde5d05 100644
--- a/backend/endpoints/sockets/scan.py
+++ b/backend/endpoints/sockets/scan.py
@@ -271,9 +271,7 @@ async def _identify_rom(
                 )
             )
         except IntegrityError:
-            # A concurrent scan already created this ROM ((platform_id, fs_name)
-            # is unique). That scan owns the full processing of this file, so
-            # skip it here instead of inserting a duplicate library entry.
+            # A concurrent scan already created this ROM, so skip it here.
             log.debug(
                 f"Skipping {hl(fs_rom['fs_name'])}: already created by a concurrent scan"
             )
diff --git a/backend/models/rom.py b/backend/models/rom.py
index 13610d26e..99bc81c2d 100644
--- a/backend/models/rom.py
+++ b/backend/models/rom.py
@@ -208,9 +208,7 @@ class Rom(BaseModel):
     libretro_id: Mapped[str | None] = mapped_column(String(length=64), default=None)
 
     __table_args__ = (
-        # A platform folder can't hold two entries with the same name on disk,
-        # so (platform_id, fs_name) is unique. Enforcing it also stops racing
-        # scans from inserting the same ROM twice.
+        # Enforce unique fs name per platform to avoid duplicates
         Index("idx_roms_platform_id_fs_name", "platform_id", "fs_name", unique=True),
         # Covers the sibling_roms view self-join
         Index(