utils/text_utils.py

def sentence_safe_trim(text: str, max_chars: int) -> str:
    """
    Trim text to the last complete sentence within max_chars.
    Handles both Devanagari '।' and standard '.' full stops.
    If no sentence boundary is found, falls back to word boundary to avoid word cut-offs.
    """
    if len(text) <= max_chars:
        return text

    truncated = text[:max_chars]

    # Find the last sentence boundary
    last_devanagari = truncated.rfind('।')
    last_period = truncated.rfind('.')
    last_boundary = max(last_devanagari, last_period)

    if last_boundary > 0:
        return truncated[:last_boundary + 1].strip()

    # Fallback 1: word boundary (space, newline) if no full stop
    last_space = max(truncated.rfind(' '), truncated.rfind('\n'))
    if last_space > 0:
        return truncated[:last_space].strip() + '...'

    # Fallback 2: hard trim
    return truncated