Add source code files

src/cronparse/parser.py

@@ -0,0 +1,91 @@
+"""Cron expression parsing and validation module."""
+
+from typing import Dict, Any, Tuple, Optional
+from croniter import croniter
+
+
+def validate_cron(expression: str) -> Tuple[bool, Optional[str]]:
+    """Validate a cron expression.
+
+    Args:
+        expression: The cron expression to validate.
+
+    Returns:
+        Tuple of (is_valid, error_message).
+    """
+    try:
+        is_valid = croniter.is_valid(expression)
+        if is_valid:
+            return True, None
+        else:
+            return False, "Invalid cron expression format"
+    except Exception as e:
+        return False, str(e)
+
+
+def parse_cron(expression: str) -> Tuple[bool, Dict[str, Any]]:
+    """Parse a cron expression and return detailed breakdown.
+
+    Args:
+        expression: The cron expression to parse.
+
+    Returns:
+        Tuple of (is_valid, result_dict).
+        result_dict contains: minute, hour, day, month, day_of_week, command.
+    """
+    try:
+        parts = expression.split()
+
+        if len(parts) < 5:
+            raise ValueError("Invalid cron expression: must have at least 5 fields")
+
+        result = {
+            "minute": parts[0],
+            "hour": parts[1],
+            "day": parts[2],
+            "month": parts[3],
+            "day_of_week": parts[4],
+        }
+
+        if len(parts) > 5:
+            command = " ".join(parts[5:])
+            if command:
+                result["command"] = command
+
+        return True, result
+    except Exception as e:
+        return False, {"error": str(e)}
+
+
+def parse_field_value(field: str, value: str) -> list:
+    """Parse a single cron field value into a list of values.
+
+    Args:
+        field: The field name (minute, hour, day, month, dow).
+        value: The field value string.
+
+    Returns:
+        List of integer values or special strings.
+    """
+    values = []
+    parts = value.split(",")
+
+    for part in parts:
+        part = part.strip()
+        if "/" in part:
+            base, step = part.split("/")
+            base = base.strip() if base.strip() else "*"
+            step = int(step)
+            values.append(f"{base}/step:{step}")
+        elif "-" in part:
+            start, end = part.split("-")
+            values.extend(range(int(start), int(end) + 1))
+        elif part == "*":
+            values.append("*")
+        else:
+            try:
+                values.append(int(part))
+            except ValueError:
+                values.append(part)
+
+    return values