Merge pull request #892 from ivanbarsukov/template_substitution

Refactor output template field substitution logic

app/ytdl.py

@@ -11,13 +11,53 @@ import re
 import types
 import dbm
 import subprocess
+from typing import Any
+from functools import lru_cache
 
 import yt_dlp.networking.impersonate
+from yt_dlp.utils import STR_FORMAT_RE_TMPL, STR_FORMAT_TYPES
 from dl_formats import get_format, get_opts, AUDIO_FORMATS
 from datetime import datetime
 
 log = logging.getLogger('ytdl')
 
+
+@lru_cache(maxsize=None)
+def _compile_outtmpl_pattern(field: str) -> re.Pattern:
+    """Compile a regex pattern to match a specific field in an output template, including optional format specifiers."""
+    conversion_types = f"[{re.escape(STR_FORMAT_TYPES)}]"
+    return re.compile(STR_FORMAT_RE_TMPL.format(re.escape(field), conversion_types))
+
+
+def _outtmpl_substitute_field(template: str, field: str, value: Any) -> str:
+    """Substitute a single field in an output template, applying any format specifiers to the value."""
+    pattern = _compile_outtmpl_pattern(field)
+
+    def replacement(match: re.Match) -> str:
+        if match.group("has_key") is None:
+            return match.group(0)
+
+        prefix = match.group("prefix") or ""
+        format_spec = match.group("format")
+
+        if not format_spec:
+            return f"{prefix}{value}"
+
+        conversion_type = format_spec[-1]
+        try:
+            if conversion_type in "diouxX":
+                coerced_value = int(value)
+            elif conversion_type in "eEfFgG":
+                coerced_value = float(value)
+            else:
+                coerced_value = value
+
+            return f"{prefix}{('%' + format_spec) % coerced_value}"
+        except (ValueError, TypeError):
+            return f"{prefix}{value}"
+
+    return pattern.sub(replacement, template)
+
 def _convert_generators_to_lists(obj):
     """Recursively convert generators to lists in a dictionary to make it pickleable."""
     if isinstance(obj, types.GeneratorType):
@@ -426,7 +466,7 @@ class DownloadQueue:
         base_directory = self.config.DOWNLOAD_DIR if (quality != 'audio' and format not in AUDIO_FORMATS) else self.config.AUDIO_DOWNLOAD_DIR
         if folder:
             if not self.config.CUSTOM_DIRS:
-                return None, {'status': 'error', 'msg': f'A folder for the download was specified but CUSTOM_DIRS is not true in the configuration.'}
+                return None, {'status': 'error', 'msg': 'A folder for the download was specified but CUSTOM_DIRS is not true in the configuration.'}
             dldirectory = os.path.realpath(os.path.join(base_directory, folder))
             real_base_directory = os.path.realpath(base_directory)
             if not dldirectory.startswith(real_base_directory):
@@ -451,13 +491,13 @@ class DownloadQueue:
                 output = self.config.OUTPUT_TEMPLATE_PLAYLIST
             for property, value in entry.items():
                 if property.startswith("playlist"):
-                    output = output.replace(f"%({property})s", str(value))
+                    output = _outtmpl_substitute_field(output, property, value)
         if entry is not None and entry.get('channel_index') is not None:
             if len(self.config.OUTPUT_TEMPLATE_CHANNEL):
                 output = self.config.OUTPUT_TEMPLATE_CHANNEL
             for property, value in entry.items():
                 if property.startswith("channel"):
-                    output = output.replace(f"%({property})s", str(value))
+                    output = _outtmpl_substitute_field(output, property, value)
         ytdl_options = dict(self.config.YTDL_OPTIONS)
         playlist_item_limit = getattr(dl, 'playlist_item_limit', 0)
         if playlist_item_limit > 0: