Add devterm tools and TUI menu

devterm/tools/cron_tool.py

@@ -0,0 +1,98 @@
+from datetime import datetime, timedelta
+
+
+def validate_cron(cron_expr: str) -> bool:
+    parts = cron_expr.strip().split()
+    if len(parts) not in [5, 6]:
+        return False
+
+    try:
+        minute, hour, day, month, dow = parts[:5]
+        _validate_cron_field(minute, 0, 59)
+        _validate_cron_field(hour, 0, 23)
+        _validate_cron_field(day, 1, 31)
+        _validate_cron_field(month, 1, 12)
+        _validate_cron_field(dow, 0, 7)
+        return True
+    except (ValueError, IndexError):
+        return False
+
+
+def _validate_cron_field(value: str, min_val: int, max_val: int) -> bool:
+    if value == "*":
+        return True
+    if "/" in value:
+        value, step = value.split("/", 1)
+        step = int(step)
+    if "-" in value:
+        start, end = value.split("-", 1)
+        if not (min_val <= int(start) <= max_val and min_val <= int(end) <= max_val):
+            raise ValueError
+        return True
+    if "," in value:
+        for v in value.split(","):
+            if not _validate_cron_field(v, min_val, max_val):
+                raise ValueError
+        return True
+    int(value)
+    return True
+
+
+def get_next_run(cron_expr: str, current_time: datetime = None) -> str:
+    if current_time is None:
+        current_time = datetime.now()
+
+    parts = cron_expr.strip().split()
+    minute, hour, day, month, dow = parts[:5]
+    second = parts[5] if len(parts) == 6 else "0"
+
+    next_time = current_time.replace(second=int(second), microsecond=0)
+    next_time += timedelta(minutes=1)
+
+    max_iterations = 366 * 24 * 60
+    for _ in range(max_iterations):
+        if _matches_cron(next_time, minute, hour, day, month, dow):
+            return next_time.strftime("%Y-%m-%d %H:%M:%S")
+        next_time += timedelta(minutes=1)
+
+    return "Could not calculate next run"
+
+
+def _matches_cron(dt: datetime, minute: str, hour: str, day: str, month: str, dow: str) -> bool:
+    return (
+        _matches_field(dt.minute, minute) and
+        _matches_field(dt.hour, hour) and
+        _matches_field(dt.day, day) and
+        _matches_field(dt.month, month) and
+        _matches_dow(dt.weekday(), dow)
+    )
+
+
+def _matches_field(value: int, pattern: str) -> bool:
+    if pattern == "*":
+        return True
+    if "/" in pattern:
+        pattern, step = pattern.split("/", 1)
+        if pattern == "*":
+            return value % int(step) == 0
+    if "-" in pattern:
+        start, end = pattern.split("-", 1)
+        return int(start) <= value <= int(end)
+    if "," in pattern:
+        return str(value) in pattern.split(",")
+    return value == int(pattern)
+
+
+def _matches_dow(weekday: int, pattern: str) -> bool:
+    if pattern == "*":
+        return True
+    if "/" in pattern:
+        pattern, step = pattern.split("/", 1)
+        if pattern == "*":
+            return weekday % int(step) == 0
+    if "-" in pattern:
+        start, end = pattern.split("-", 1)
+        return int(start) <= weekday <= int(end)
+    if "," in pattern:
+        return str(weekday) in pattern.split(",")
+    return weekday == int(pattern)