ensure line uniqueness when editing playlists in case of virtual file…

…name collision

rose/playlists.py

@@ -1,5 +1,6 @@
 import json
 import logging
+from collections import Counter
 from pathlib import Path
 from typing import Any
 
@@ -145,13 +146,24 @@ def edit_playlist_in_editor(c: Config, playlist_name: str) -> None:
         with path.open("rb") as fp:
             data = tomllib.load(fp)
         raw_tracks = data.get("tracks", [])
-        edited_track_descriptions = click.edit(
-            "\n".join([r["description_meta"] for r in raw_tracks])
-        )
+
+        # Because tracks are not globally unique, we append the UUID if there are any conflicts.
+        # discriminator.
+        lines_to_edit: list[str] = []
+        uuid_mapping: dict[str, str] = {}
+        line_occurrences = Counter([r["description_meta"] for r in raw_tracks])
+        for r in raw_tracks:
+            if line_occurrences[r["description_meta"]] > 1:
+                line = f'{r["description_meta"]} [{r["uuid"]}]'
+            else:
+                line = r["description_meta"]
+            lines_to_edit.append(line)
+            uuid_mapping[line] = r["uuid"]
+
+        edited_track_descriptions = click.edit("\n".join(lines_to_edit))
         if edited_track_descriptions is None:
             logger.info("Aborting: metadata file not submitted.")
             return
-        uuid_mapping = {r["description_meta"]: r["uuid"] for r in raw_tracks}
 
         edited_tracks: list[dict[str, Any]] = []
         for desc in edited_track_descriptions.strip().split("\n"):

rose/playlists_test.py

@@ -1,10 +1,12 @@
+import shutil
 from pathlib import Path
 from typing import Any
 
 import pytest
 import tomllib
 
-from rose.cache import connect
+from conftest import TEST_RELEASE_1
+from rose.cache import connect, update_cache
 from rose.config import Config
 from rose.playlists import (
     add_track_to_playlist,
@@ -137,3 +139,40 @@ def test_edit_playlists_remove_track(monkeypatch: Any, config: Config, source_di
     with filepath.open("rb") as fp:
         data = tomllib.load(fp)
     assert len(data["tracks"]) == 1
+
+
+def test_edit_playlists_duplicate_track_name(monkeypatch: Any, config: Config) -> None:
+    """
+    When there are duplicate virtual filenames, we append UUID. Check that it works by asserting on
+    the seen text and checking that reversing the order works.
+    """
+    # Generate conflicting virtual tracknames by having two copies of a release in the library.
+    shutil.copytree(TEST_RELEASE_1, config.music_source_dir / "a")
+    shutil.copytree(TEST_RELEASE_1, config.music_source_dir / "b")
+    update_cache(config)
+
+    with connect(config) as conn:
+        # Get the first track of each release.
+        cursor = conn.execute("SELECT id FROM tracks WHERE source_path LIKE '%01.m4a'")
+        track_ids = [r["id"] for r in cursor]
+        assert len(track_ids) == 2
+
+    create_playlist(config, "You & Me")
+    for tid in track_ids:
+        add_track_to_playlist(config, "You & Me", tid)
+
+    seen = ""
+    def editfn(x: str) -> str:
+        nonlocal seen
+        seen = x
+        return "\n".join(reversed(x.split("\n")))
+
+    monkeypatch.setattr("rose.playlists.click.edit", editfn)
+    edit_playlist_in_editor(config, "You & Me")
+
+    assert seen == "\n".join([f"BLACKPINK - Track 1.m4a [{tid}]" for tid in track_ids])
+
+    with (config.music_source_dir / "!playlists" / "You & Me.toml").open("rb") as fp:
+        data = tomllib.load(fp)
+    assert data["tracks"][0]["uuid"] == track_ids[1]
+    assert data["tracks"][1]["uuid"] == track_ids[0]