class TextChunker:
    def __init__(self, chunk_size: int = 900, overlap: int = 120) -> None:
        self._chunk_size = chunk_size
        self._overlap = overlap

    def chunk(self, text: str) -> list[str]:
        cleaned = text.replace("\r\n", "\n")
        if not cleaned.strip():
            return []
        chunks: list[str] = []
        start = 0
        while start < len(cleaned):
            end = min(len(cleaned), start + self._chunk_size)
            piece = cleaned[start:end].strip()
            if piece:
                chunks.append(piece)
            if end == len(cleaned):
                break
            start = max(0, end - self._overlap)
        return chunks