"""Input Validation Utilities"""
from pathlib import Path
from typing import Optional
import logging

logger = logging.getLogger(__name__)

def validate_code(code: str) -> None:
    """
    Validate code input.
    
    Args:
        code: Source code string
        
    Raises:
        ValueError: If code is invalid
    """
    if not code or not code.strip():
        raise ValueError("Code cannot be empty")
    
    if len(code) > 1_000_000:  # 1MB limit
        raise ValueError("Code size exceeds maximum limit (1MB)")

def validate_path(path: str) -> None:
    """
    Validate file/directory path.
    
    Args:
        path: File or directory path
        
    Raises:
        ValueError: If path is invalid
    """
    if not path:
        raise ValueError("Path cannot be empty")
    
    path_obj = Path(path)
    if not path_obj.exists():
        raise ValueError(f"Path does not exist: {path}")
    
    # Security: prevent path traversal
    try:
        path_obj.resolve()
    except Exception as e:
        raise ValueError(f"Invalid path: {e}")

def validate_language(language: str) -> str:
    """
    Validate and normalize language parameter.
    
    Args:
        language: Programming language
        
    Returns:
        str: Normalized language name
        
    Raises:
        ValueError: If language is not supported
    """
    valid_languages = ["auto", "python", "javascript", "typescript"]
    language = language.lower().strip()
    
    if language not in valid_languages:
        raise ValueError(
            f"Unsupported language: {language}. "
            f"Supported: {', '.join(valid_languages)}"
        )
    
    return language