"""腾讯云文本翻译 TMT。"""
from __future__ import annotations

import asyncio
import logging
import random
from typing import Any

from tencentcloud.common import credential
from tencentcloud.common.exception.tencent_cloud_sdk_exception import (
    TencentCloudSDKException,
)
from tencentcloud.tmt.v20180321 import models, tmt_client

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

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


def _normalize_lang(code: str) -> str:
    """把 BCP-47(可能带地区后缀)简化成主语言,TMT 用的 2 字母 code。

    例:
      en-gb / en-us / en-au -> en
      zh-cn / zh-tw        -> zh
      ja-jp                -> ja
      "" / auto            -> 原样
    """
    if not code or code == "auto":
        return code
    return code.split("-")[0].lower()


# 常见语种映射(归一化后再过这层;保留覆盖是兜底)
_LANG_MAP = {
    "en": "en",
    "zh": "zh",
    "ja": "ja",
    "ko": "ko",
    "fr": "fr",
    "de": "de",
    "es": "es",
    "ru": "ru",
    "ar": "ar",
}


class TencentTranslator(BaseTranslator):
    name = "tencent"

    def __init__(self):
        if not settings.tencentcloud_secret_id or not settings.tencentcloud_secret_key:
            raise RuntimeError("Tencent Cloud credentials missing")
        self.cred = credential.Credential(
            settings.tencentcloud_secret_id, settings.tencentcloud_secret_key
        )
        self.client = tmt_client.TmtClient(self.cred, settings.tencentcloud_region)

    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)

        # 关键:BCP-47 归一化(避免 en-gb / en-us / zh-cn / ja-jp 等被 TMT 拒)
        source = _normalize_lang(source)
        target = _normalize_lang(target)
        source = _LANG_MAP.get(source, source if source != "auto" else "auto")
        target = _LANG_MAP.get(target, target)

        # 简单重试
        for attempt in range(2):
            try:
                req = models.TextTranslateRequest()
                req.SourceText = text
                req.Source = source
                req.Target = target
                req.ProjectId = 0
                # SDK 同步调用 → 放线程池
                resp: Any = await asyncio.to_thread(self.client.TextTranslate, req)
                out = getattr(resp, "TargetText", "") or ""
                return TranslationResult(
                    text=out, engine=self.name, chars=len(text), cached=False
                )
            except TencentCloudSDKException as e:
                logger.warning("tencent translate attempt %s failed: %s", attempt, e)
                if attempt == 0:
                    await asyncio.sleep(0.5 + random.random())
                else:
                    raise
        raise RuntimeError("unreachable")