fix: normalize time tags in fetched lrc (why [00:17:06]?)

lrcfetch/lrc.py

@@ -0,0 +1,46 @@
+"""Shared LRC time-tag utilities.
+
+Handles detection, normalization, and sync-status checks for LRC lyrics.
+"""
+
+import re
+from lrcfetch.models import CacheStatus
+
+# Standard format: [mm:ss.cc] or [mm:ss.ccc]
+_STANDARD_TAG_RE = re.compile(r"\[\d{2}:\d{2}\.\d{2,3}\]")
+
+# Non-standard format: [mm:ss:cc] (two colons instead of dot)
+_COLON_TAG_RE = re.compile(r"\[(\d{2}:\d{2}):(\d{2,3})\]")
+
+# Matches any LRC time tag (standard or non-standard) at start of line
+LRC_LINE_RE = re.compile(r"^\[(\d{2}:\d{2}[.:]\d{2,3})\]", re.MULTILINE)
+
+# All-zero tags
+_ZERO_TAG_RE = re.compile(r"^\[00:00[.:]0{2,3}\]$")
+
+
+def normalize_tags(text: str) -> str:
+    """Convert non-standard time tags [mm:ss:cc] to standard [mm:ss.cc]."""
+    return _COLON_TAG_RE.sub(r"[\1.\2]", text)
+
+
+def is_synced(text: str) -> bool:
+    """Check whether text contains actual LRC time tags with non-zero times.
+
+    Returns False if no tags exist or all tags are [00:00.00].
+    Handles both [mm:ss.cc] and [mm:ss:cc] formats.
+    """
+    tags = _STANDARD_TAG_RE.findall(text)
+    # Also check non-standard format
+    tags += [f"[{m.group(1)}.{m.group(2)}]" for m in _COLON_TAG_RE.finditer(text)]
+    if not tags:
+        return False
+    for tag in tags:
+        if not _ZERO_TAG_RE.match(tag):
+            return True
+    return False
+
+
+def detect_sync_status(text: str) -> CacheStatus:
+    """Determine whether lyrics contain meaningful LRC time tags."""
+    return CacheStatus.SUCCESS_SYNCED if is_synced(text) else CacheStatus.SUCCESS_UNSYNCED