From d9f251b2fc7e870a40c97dab3263be1b9ab2fc01 Mon Sep 17 00:00:00 2001
From: Silas Oettinghaus <silas@oettinghaus.org>
Date: Wed, 15 Apr 2026 21:45:17 +0200
Subject: [PATCH] fix: implement retry logic with ETag synchronization for
 Tidal playlist modifications and add test script

---
 app.py                                 |  9 ++++---
 session.json                           |  1 +
 src/spotify_to_tidal/tidalapi_patch.py | 37 ++++++++++++++++++++++----
 test_tidal_delete.py                   |  2 ++
 4 files changed, 40 insertions(+), 9 deletions(-)
 create mode 100644 test_tidal_delete.py

diff --git a/app.py b/app.py
index 4129a54..eb4ea3a 100644
--- a/app.py
+++ b/app.py
@@ -256,8 +256,9 @@ with tab_my:
                         st.session_state[tracks_key] = tracks
                         if err:
                             st.session_state[f"tracks_err_{pid}"] = err
-                        st.rerun()
-                else:
+                        cached_tracks = tracks
+
+                if cached_tracks is not None:
                     err = st.session_state.get(f"tracks_err_{pid}")
                     if err:
                         st.warning(err)
@@ -274,7 +275,7 @@ with tab_my:
                         st.dataframe(
                             pd.DataFrame(rows),
                             hide_index=True,
-                            use_container_width=True,
+                            width="stretch",
                             height=min(40 + len(rows) * 35, 300),
                             column_config={
                                 "":       st.column_config.TextColumn("", width="small"),
@@ -400,7 +401,7 @@ with tab_nf:
             for a, t in items
         ]
         if nf_rows:
-            st.dataframe(pd.DataFrame(nf_rows), hide_index=True, use_container_width=True,
+            st.dataframe(pd.DataFrame(nf_rows), hide_index=True, width="stretch",
                          height=min(80 + len(nf_rows) * 35, 500))
         else:
             st.info("No entries for this filter.")
diff --git a/session.json b/session.json
index 310b25b..1160e2e 100644
--- a/session.json
+++ b/session.json
@@ -1,5 +1,6 @@
 {
   "watched": [
+    "2Dz5fstoYCa1wm2sOtZlwT",
     "2sLEYLo3a6dDHbl4ypUkcl",
     "3Sjb6ZlsPxIpzOMZVoq1pW",
     "3eNcChQ2KssR8QjuV7KUEc",
diff --git a/src/spotify_to_tidal/tidalapi_patch.py b/src/spotify_to_tidal/tidalapi_patch.py
index 9da23cc..1b743cc 100644
--- a/src/spotify_to_tidal/tidalapi_patch.py
+++ b/src/spotify_to_tidal/tidalapi_patch.py
@@ -5,11 +5,26 @@ import tidalapi
 from tqdm import tqdm
 from tqdm.asyncio import tqdm as atqdm
 
+import time
+
 def _remove_indices_from_playlist(playlist: tidalapi.UserPlaylist, indices: List[int]):
-    headers = {'If-None-Match': playlist._etag}
-    index_string = ",".join(map(str, indices))
-    playlist.request.request('DELETE', (playlist._base_url + '/items/%s') % (playlist.id, index_string), headers=headers)
-    playlist._reparse()
+    if not playlist._etag:
+        playlist._reparse()
+    
+    for attempt in range(5):
+        headers = {'If-None-Match': playlist._etag} if playlist._etag else None
+        index_string = ",".join(map(str, indices))
+        try:
+            res = playlist.request.request('DELETE', (playlist._base_url + '/items/%s') % (playlist.id, index_string), headers=headers)
+            playlist._etag = res.headers.get('etag', playlist._etag)
+            playlist.num_tracks = max(0, playlist.num_tracks - len(indices))
+            return
+        except Exception as e:
+            if "412" in str(e) and attempt < 4:
+                time.sleep(1)
+                playlist._reparse()
+            else:
+                raise
 
 def clear_tidal_playlist(playlist: tidalapi.UserPlaylist, chunk_size: int=20):
     with tqdm(desc="Erasing existing tracks from Tidal playlist", total=playlist.num_tracks) as progress:
@@ -19,11 +34,23 @@ def clear_tidal_playlist(playlist: tidalapi.UserPlaylist, chunk_size: int=20):
             progress.update(len(indices))
     
 def add_multiple_tracks_to_playlist(playlist: tidalapi.UserPlaylist, track_ids: List[int], chunk_size: int=20):
+    if not playlist._etag:
+        playlist._reparse()
+        
     offset = 0
     with tqdm(desc="Adding new tracks to Tidal playlist", total=len(track_ids)) as progress:
         while offset < len(track_ids):
             count = min(chunk_size, len(track_ids) - offset)
-            playlist.add(track_ids[offset:offset+chunk_size])
+            for attempt in range(5):
+                try:
+                    playlist.add(track_ids[offset:offset+chunk_size])
+                    break
+                except Exception as e:
+                    if "412" in str(e) and attempt < 4:
+                        time.sleep(1)
+                        playlist._reparse()
+                    else:
+                        raise
             offset += count
             progress.update(count)
 
diff --git a/test_tidal_delete.py b/test_tidal_delete.py
new file mode 100644
index 0000000..394eb33
--- /dev/null
+++ b/test_tidal_delete.py
@@ -0,0 +1,2 @@
+import requests
+# I just want to write a quick script to test if the E-Tag is updated correctly