# -*- coding: utf-8 -*-
"""对话开场画面识别 —— 用多模态 LLM（qwen3-vl-flash）识别实时画面中的人数、性别等，
并把结果作为上下文注入对话，让 AI 了解当前在场观众。

与 vision_yolo（YOLO 数人脸/姿态）互补：这里用 LLM 做语义级理解（人数、性别构成、场景描述）。
"""
import json
import logging
import ssl
import urllib.request

import certifi

from .config import settings

log = logging.getLogger("dpm.vision")

_SSL_CTX = ssl.create_default_context(cafile=certifi.where())

_DEFAULT_PROMPT = (
    "请识别这张实时画面，只输出一个 JSON 对象（不要输出任何其他文字）："
    '{"people": 画面中人数(int), "males": 其中男性人数(int), "females": 其中女性人数(int), '
    '"desc": 一句话中文描述画面（含大致人数、性别构成、人物大致状态，如年龄/坐站/是否看屏幕）。'
    "若画面无人或不确定，则 people=0、males=0、females=0，desc='画面中暂时没有人'。"
)


def analyze_scene(jpeg_b64: str, prompt: str = "") -> dict:
    """调用多模态 LLM 识别画面中人数/性别，返回 {ok, people, males, females, desc}。"""
    payload = {
        "model": settings.VISION_LLM_MODEL,
        "messages": [{
            "role": "user",
            "content": [
                {"type": "text", "text": prompt or _DEFAULT_PROMPT},
                {"type": "image_url", "image_url": {"url": f"data:image/jpeg;base64,{jpeg_b64}"}},
            ],
        }],
    }
    req = urllib.request.Request(
        f"{settings.LLM_BASE_URL}/chat/completions",
        data=json.dumps(payload, ensure_ascii=False).encode("utf-8"),
        headers={
            "Content-Type": "application/json",
            "Authorization": f"Bearer {settings.DASHSCOPE_API_KEY}",
        },
    )
    with urllib.request.urlopen(req, timeout=30, context=_SSL_CTX) as resp:
        data = json.loads(resp.read().decode("utf-8"))
    content = data["choices"][0]["message"].get("content") or ""
    return _parse(content)


def _parse(text: str) -> dict:
    """从模型输出中抽取 JSON 对象并规范化为结果 dict。"""
    text = (text or "").strip()
    if text.startswith("```"):
        lines = [l for l in text.splitlines() if not l.strip().startswith("```")]
        text = "\n".join(lines).strip()
    obj: dict = {}
    i, j = text.find("{"), text.rfind("}")
    if i != -1 and j > i:
        try:
            obj = json.loads(text[i:j + 1])
        except Exception:  # noqa: BLE001
            log.warning("vision llm: 返回 JSON 解析失败: %s", text[:120])
    people = _as_int(obj.get("people"))
    males = _as_int(obj.get("males"))
    females = _as_int(obj.get("females"))
    return {
        "ok": True,
        "people": people,
        "males": males,
        "females": females,
        "desc": str(obj.get("desc") or "").strip(),
    }


def _as_int(v):
    try:
        return int(float(v))
    except (TypeError, ValueError):
        return 0