dify

dify/api/libs/time_parser.py

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+"""Time duration parser utility."""
+
+import re
+from datetime import UTC, datetime, timedelta
+
+
+def parse_time_duration(duration_str: str) -> timedelta | None:
+    """
+    Parse time duration string to timedelta.
+
+    Supported formats:
+    - 7d: 7 days
+    - 4h: 4 hours
+    - 30m: 30 minutes
+    - 30s: 30 seconds
+
+    Args:
+        duration_str: Duration string (e.g., "7d", "4h", "30m", "30s")
+
+    Returns:
+        timedelta object or None if invalid format
+    """
+    if not duration_str:
+        return None
+
+    # Pattern: number followed by unit (d, h, m, s)
+    pattern = r"^(\d+)([dhms])$"
+    match = re.match(pattern, duration_str.lower())
+
+    if not match:
+        return None
+
+    value = int(match.group(1))
+    unit = match.group(2)
+
+    if unit == "d":
+        return timedelta(days=value)
+    elif unit == "h":
+        return timedelta(hours=value)
+    elif unit == "m":
+        return timedelta(minutes=value)
+    elif unit == "s":
+        return timedelta(seconds=value)
+
+    return None
+
+
+def get_time_threshold(duration_str: str | None) -> datetime | None:
+    """
+    Get datetime threshold from duration string.
+
+    Calculates the datetime that is duration_str ago from now.
+
+    Args:
+        duration_str: Duration string (e.g., "7d", "4h", "30m", "30s")
+
+    Returns:
+        datetime object representing the threshold time, or None if no duration
+    """
+    if not duration_str:
+        return None
+
+    duration = parse_time_duration(duration_str)
+    if duration is None:
+        return None
+
+    return datetime.now(UTC) - duration