"""File utility functions."""

import os
from typing import Generator, Optional


def find_files(
    pattern: str,
    base_path: Optional[str] = None,
    recursive: bool = True,
) -> Generator[str, None, None]:
    """Find files matching a pattern.

    Args:
        pattern: File pattern (e.g., "**/*.py")
        base_path: Base path to search from
        recursive: Whether to search recursively

    Yields:
        Matching file paths
    """
    import glob

    search_pattern = pattern
    if base_path:
        search_pattern = os.path.join(base_path, pattern)

    matches = glob.glob(search_pattern, recursive=recursive)
    for match in sorted(matches):
        if os.path.isfile(match):
            yield match


def read_file_safe(file_path: str, encoding: str = "utf-8") -> tuple[str, Optional[str]]:
    """Read file contents safely.

    Args:
        file_path: Path to file
        encoding: File encoding

    Returns:
        Tuple of (content, None) on success or (None, error_message) on failure
    """
    try:
        with open(file_path, "r", encoding=encoding) as f:
            return f.read(), None
    except UnicodeDecodeError:
        try:
            with open(file_path, "r", encoding="latin-1") as f:
                return f.read(), None
        except Exception as e:
            return None, str(e)
    except Exception as e:
        return None, str(e)


def get_file_extension(file_path: str) -> str:
    """Get file extension in lowercase.

    Args:
        file_path: Path to file

    Returns:
        File extension including the dot
    """
    _, ext = os.path.splitext(file_path)
    return ext.lower()


def ensure_directory_exists(path: str) -> None:
    """Ensure directory exists, create if needed.

    Args:
        path: Directory path
    """
    os.makedirs(path, exist_ok=True)


def get_relative_path(file_path: str, base_path: str) -> str:
    """Get relative path from base path.

    Args:
        file_path: Full file path
        base_path: Base path

    Returns:
        Relative path
    """
    try:
        return os.path.relpath(file_path, base_path)
    except ValueError:
        return file_path