"""智谱 GLM 翻译(OpenAI 兼容协议)。

- 端点:https://open.bigmodel.cn/api/paas/v4/chat/completions
- 模型:glm-4-flash(免费,默认) / glm-4.5 / glm-4.6 / glm-4-air 等
- 鉴权:Bearer <api_key>

设计上独立于 LlmClient,专门走 zhipu_* 配置,避免和 LLM 智能增强共用 client 的节流。
"""
from __future__ import annotations

import asyncio
import logging
import random

import httpx

from app.config import settings
from app.services.translation.base import BaseTranslator, TranslationResult

logger = logging.getLogger("news.translate.zhipu")


# 经过实测,这套 prompt 在 GLM-4-Flash 上输出稳定(不夹带 reasoning / 注释)。
_SYSTEM_PROMPT = """你是一个即时翻译助手。对于用户输入的英文或日文文章,请直接输出对应的简体中文译文。严格遵守:

不要进行任何分步思考、不要输出分析、不要添加注释或说明。

只输出中文译文本身,不包含任何额外文字(如"翻译结果:"、"以下是中文:"等)。

如果输入内容既非英文也非日文,仅回复:"仅支持英文或日文翻译为中文。" """


class ZhipuTranslator(BaseTranslator):
    """智谱 GLM 翻译(OpenAI 兼容协议)。"""

    name = "zhipu"

    def __init__(self):
        if not settings.zhipu_api_key:
            raise RuntimeError("Zhipu API key missing")
        self.api_key = settings.zhipu_api_key
        self.base_url = settings.zhipu_base_url.rstrip("/")
        self.model = settings.zhipu_model
        self.interval_sec = settings.zhipu_interval_sec

    def is_configured(self) -> bool:
        return bool(self.api_key)

    async def translate(
        self, text: str, source: str = "auto", target: str = "zh"
    ) -> TranslationResult:
        if not text.strip():
            return TranslationResult(text=text, engine=self.name, chars=0)
        if not self.is_configured():
            raise RuntimeError("Zhipu API key missing")

        url = f"{self.base_url}/chat/completions"
        payload = {
            "model": self.model,
            "messages": [
                {"role": "system", "content": _SYSTEM_PROMPT},
                {"role": "user", "content": text},
            ],
            "temperature": 0.0,
            "max_tokens": max(256, len(text) * 3),
            "stream": False,
        }
        headers = {
            "Authorization": f"Bearer {self.api_key}",
            "Content-Type": "application/json",
        }

        # 简单串行 + 重试 1 次
        last_exc: Exception | None = None
        for attempt in range(2):
            try:
                async with httpx.AsyncClient(timeout=60.0) as client:
                    r = await client.post(url, json=payload, headers=headers)
                if r.status_code >= 500:
                    raise RuntimeError(f"Zhipu 5xx: {r.status_code} {r.text[:200]}")
                if r.status_code == 429:
                    raise RuntimeError(f"Zhipu 限流: {r.text[:200]}")
                if r.status_code != 200:
                    raise RuntimeError(f"Zhipu {r.status_code}: {r.text[:300]}")
                data = r.json()
                if "error" in data:
                    raise RuntimeError(f"Zhipu error: {data['error']}")
                content = (
                    data.get("choices", [{}])[0]
                    .get("message", {})
                    .get("content", "")
                    .strip()
                )
                if not content:
                    raise RuntimeError(f"Zhipu empty content: {r.text[:300]}")
                await asyncio.sleep(self.interval_sec)
                return TranslationResult(
                    text=content, engine=self.name, chars=len(text), cached=False
                )
            except Exception as e:
                last_exc = e
                logger.warning("zhipu attempt %s failed: %s", attempt, e)
                if attempt == 0:
                    await asyncio.sleep(0.5 + random.random())
                else:
                    raise
        assert last_exc is not None
        raise last_exc