Propagate missing playlist context fields (playlist_count, playlist_autonumber, n_entries, __last_playlist_index)

The playlist/channel processing loop now sets playlist_count,
playlist_autonumber, n_entries, and __last_playlist_index on each
video entry so that templates like %(playlist_autonumber)s,
%(playlist_count)s, and %(playlist_index&{} - |)s resolve correctly
instead of showing NA.

Also updates _compact_persisted_entry to preserve n_entries and
__last_playlist_index across restarts.

Fixes #692

Agent-Logs-Url: https://github.com/alexta69/metube/sessions/b5aeb55a-3197-4a14-b8b4-96c9a67796e8

Co-authored-by: alexta69 <7450369+alexta69@users.noreply.github.com>

app/tests/test_ytdl_utils.py

@@ -93,6 +93,35 @@ class ResolveOuttmplFieldsTests(unittest.TestCase):
         result = _resolve_outtmpl_fields("%(playlist_index+100)d", info, ("playlist",))
         self.assertEqual(result, "103")
 
+    def test_playlist_count_and_autonumber(self):
+        info = {
+            "playlist_title": "My PL",
+            "playlist_index": "03",
+            "playlist_count": 10,
+            "playlist_autonumber": 3,
+            "n_entries": 10,
+            "__last_playlist_index": 10,
+        }
+        result = _resolve_outtmpl_fields(
+            "%(playlist_title)s/%(playlist_autonumber)s of %(playlist_count)s - %(title)s.%(ext)s",
+            info,
+            ("playlist",),
+        )
+        # playlist_autonumber is auto-padded by yt-dlp using __last_playlist_index
+        self.assertEqual(result, "My PL/03 of 10 - %(title)s.%(ext)s")
+
+    def test_conditional_playlist_index(self):
+        info = {
+            "playlist_index": "5",
+            "playlist_count": 10,
+        }
+        result = _resolve_outtmpl_fields(
+            "%(playlist_index&{} - |)s%(title)s.%(ext)s",
+            info,
+            ("playlist",),
+        )
+        self.assertEqual(result, "5 - %(title)s.%(ext)s")
+
 
 class SanitizeEntryForPickleTests(unittest.TestCase):
     def test_nested(self):
@@ -250,8 +279,12 @@ class CompactPersistedEntryTests(unittest.TestCase):
         entry = {
             "playlist_index": "01",
             "playlist_title": "Playlist",
+            "playlist_count": 10,
+            "playlist_autonumber": 1,
             "channel_index": "02",
             "channel_title": "Channel",
+            "n_entries": 10,
+            "__last_playlist_index": 10,
             "formats": [{"id": "huge"}],
             "description": "big blob",
         }
@@ -263,8 +296,12 @@ class CompactPersistedEntryTests(unittest.TestCase):
             {
                 "playlist_index": "01",
                 "playlist_title": "Playlist",
+                "playlist_count": 10,
+                "playlist_autonumber": 1,
                 "channel_index": "02",
                 "channel_title": "Channel",
+                "n_entries": 10,
+                "__last_playlist_index": 10,
             },
         )
 

app/ytdl.py

@@ -295,13 +295,16 @@ _PERSISTED_DOWNLOAD_FIELDS = (
 )
 
 
+_COMPACT_ENTRY_EXTRA_KEYS = frozenset(("n_entries", "__last_playlist_index"))
+
+
 def _compact_persisted_entry(entry: Any) -> Optional[dict[str, Any]]:
     if not isinstance(entry, dict):
         return None
     compact = {
         key: value
         for key, value in entry.items()
-        if key.startswith("playlist") or key.startswith("channel")
+        if key.startswith("playlist") or key.startswith("channel") or key in _COMPACT_ENTRY_EXTRA_KEYS
     }
     return compact or None
 
@@ -893,8 +896,9 @@ class DownloadQueue:
             # Convert generator to list if needed (for len() and slicing operations)
             if isinstance(entries, types.GeneratorType):
                 entries = list(entries)
-            log.info(f'{etype} detected with {len(entries)} entries')
-            index_digits = len(str(len(entries)))
+            total_entries = len(entries)
+            log.info(f'{etype} detected with {total_entries} entries')
+            index_digits = len(str(total_entries))
             results = []
             if playlist_item_limit > 0:
                 log.info(f'Item limit is set. Processing only first {playlist_item_limit} entries')
@@ -906,6 +910,10 @@ class DownloadQueue:
                 etr["_type"] = "video"
                 etr[etype] = entry.get("id") or entry.get("channel_id") or entry.get("channel")
                 etr[f"{etype}_index"] = '{{0:0{0:d}d}}'.format(index_digits).format(index)
+                etr[f"{etype}_count"] = total_entries
+                etr[f"{etype}_autonumber"] = index
+                etr["n_entries"] = total_entries
+                etr["__last_playlist_index"] = total_entries
                 for property in ("id", "title", "uploader", "uploader_id"):
                     if property in entry:
                         etr[f"{etype}_{property}"] = entry[property]