def breakdown_txt_to_satisfy_token_limit(txt, get_token_fn, limit):
    def cut(txt_tocut, must_break_at_empty_line): # 递归
        if get_token_fn(txt_tocut) <= limit:
            return [txt_tocut]
        else:
            lines = txt_tocut.split('\n')
            estimated_line_cut = limit / get_token_fn(txt_tocut)  * len(lines)
            estimated_line_cut = int(estimated_line_cut)
            for cnt in reversed(range(estimated_line_cut)):
                if must_break_at_empty_line: 
                    if lines[cnt] != "": continue
                print(cnt)
                prev = "\n".join(lines[:cnt])
                post = "\n".join(lines[cnt:])
                if get_token_fn(prev) < limit: break
            if cnt == 0:
                print('what the fuck ?')
                raise RuntimeError("存在一行极长的文本！")
            # print(len(post))
            # 列表递归接龙
            result = [prev]
            result.extend(cut(post, must_break_at_empty_line))
            return result
    try:
        return cut(txt, must_break_at_empty_line=True)
    except RuntimeError:
        return cut(txt, must_break_at_empty_line=False)

def breakdown_txt_to_satisfy_token_limit_for_pdf(txt, get_token_fn, limit):
    def cut(txt_tocut, must_break_at_empty_line): # 递归
        if get_token_fn(txt_tocut) <= limit:
            return [txt_tocut]
        else:
            lines = txt_tocut.split('\n')
            estimated_line_cut = limit / get_token_fn(txt_tocut)  * len(lines)
            estimated_line_cut = int(estimated_line_cut)
            cnt = 0
            for cnt in reversed(range(estimated_line_cut)):
                if must_break_at_empty_line: 
                    if lines[cnt] != "": continue
                print(cnt)
                prev = "\n".join(lines[:cnt])
                post = "\n".join(lines[cnt:])
                if get_token_fn(prev) < limit: break
            if cnt == 0:
                # print('what the fuck ? 存在一行极长的文本！')
                raise RuntimeError("存在一行极长的文本！")
            # print(len(post))
            # 列表递归接龙
            result = [prev]
            result.extend(cut(post, must_break_at_empty_line))
            return result
    try:
        return cut(txt, must_break_at_empty_line=True)
    except RuntimeError:
        try:
            return cut(txt, must_break_at_empty_line=False)
        except RuntimeError:
            # 这个中文的句号是故意的，作为一个标识而存在
            res = cut(txt.replace('.', '。\n'), must_break_at_empty_line=False)
            return [r.replace('。\n', '.') for r in res]