"""思考链抽取：从 <thought>...</thought> 标签或 reasoning_content 字段提取。"""
from __future__ import annotations

import re
from typing import Optional

_THOUGHT_TAG_RE = re.compile(
    r"<(?:thought|think)>\s*([\s\S]*?)\s*</(?:thought|think)>",
    re.IGNORECASE,
)
_THOUGHT_TAG_FULL_RE = re.compile(
    r"<(?:thought|think)>[\s\S]*?</(?:thought|think)>\s*",
    re.IGNORECASE,
)


def extract_thought_and_answer(raw: str) -> tuple[str, str]:
    """从原始输出中抽出 thought 与 answer。

    Returns:
        (thought, answer)
    """
    if not raw:
        return "", ""
    thoughts = []
    for m in _THOUGHT_TAG_RE.finditer(raw):
        if m.group(1):
            thoughts.append(m.group(1).strip())
    answer = _THOUGHT_TAG_FULL_RE.sub("", raw).strip()
    return "\n\n".join(thoughts), answer


def extract_thought_from_reasoning_content(reasoning_content: Optional[str]) -> str:
    if not reasoning_content:
        return ""
    return reasoning_content.strip()


def wrap_thought(thought: str) -> str:
    """把 thought 包裹成 <thought>...</thought> 嵌入 content。"""
    if not thought:
        return ""
    return f"<thought>\n{thought}\n</thought>\n\n"