"""Formatting utilities for display and presentation."""

from abacus_common_logic.constants.math import Bytes

_SORTED_BYTE_UNITS = tuple(sorted(Bytes, key=lambda x: x.value))


def format_bytes(file_bytes: int, show_sign: bool = False) -> str:
    """Format byte size into human-readable string with appropriate unit.

    Args:
        file_bytes: Size in bytes.
        show_sign: If True, prepends '+' to positive values.
                   Negative values always show '-'.

    Returns:
        str: Formatted size string (e.g., "1.50 MB", "150.00 KB", "5.00 B").
    """
    # Find appropriate unit
    abs_bytes = abs(file_bytes)
    unit = Bytes.B
    for u in _SORTED_BYTE_UNITS:
        if abs_bytes < u.value:
            break
        unit = u

    # Convert to unit
    value = file_bytes / unit.value

    # Return formatted string
    pos_sign = '+' if show_sign and file_bytes > 0 else ''
    return f'{pos_sign}{value:.2f} {unit.name}'