SMANAGE/gvsds/wechat/broadcast.py

"""模块：公众号模板消息广播

依赖 gvsds.wechat.AccessToken 自动获取公众号 access_token。
token 失效时（errcode 40001/42001）自动清缓存以便下次刷新。

配置（app.ini [wechat] 段）：
    TEMPLATE_ID  默认模板 ID
    BATCH_SIZE   分批发送大小，默认 100

常用 API：
    from gvsds.wechat import Broadcast
    Broadcast.Send(openid, template_id, data, url='')
    Broadcast.SendBatch(openids, template_id, data, url='')
    Broadcast.BroadcastAll(openids, template_id, data)

data 格式示例：
    {'first': {'value': 'xxx'}, 'keyword1': {'value': 'yyy'}}

返回：{'success': int, 'fail': int, 'errors': [...]}
"""
import logging
import time

from django.core.cache import cache

from gvsds.app_config import get as _app_get, getint as _app_getint

from .token import AccessToken

logger = logging.getLogger(__name__)

_TEMPLATE_SEND_URL = 'https://api.weixin.qq.com/cgi-bin/message/template/send'
_BATCH_INTERVAL = 0.1  # 批次间隔秒数，防限流
_INVALID_TOKEN_CODES = (40001, 42001)  # token 失效码


class Broadcast:
    """公众号模板消息广播器。"""

    @staticmethod
    def _DefaultTemplateId():
        return _app_get('wechat', 'TEMPLATE_ID', fallback=None)

    @staticmethod
    def _BatchSize():
        size = _app_getint('wechat', 'BATCH_SIZE', fallback=100)
        return size if size > 0 else 100

    @classmethod
    def Send(cls, openid, template_id=None, data=None, url=''):
        """向单个 openid 发送模板消息。"""
        if not openid:
            return {'success': 0, 'fail': 1, 'errors': [{'openid': openid, 'error': 'openid 为空'}]}
        template_id = template_id or cls._DefaultTemplateId()
        if not template_id:
            raise RuntimeError('[Broadcast] 未指定 template_id 且未配置默认模板')
        try:
            token = AccessToken.Get('official')
        except Exception as e:
            logger.error('[Broadcast] 获取 access_token 失败: %s', e, exc_info=True)
            return {'success': 0, 'fail': 1, 'errors': [{'openid': openid, 'error': str(e)}]}
        payload = {
            'touser': openid,
            'template_id': template_id,
            'url': url or '',
            'data': data or {},
        }
        ok, err = cls._Post(token, payload)
        if ok:
            return {'success': 1, 'fail': 0, 'errors': []}
        return {'success': 0, 'fail': 1, 'errors': [{'openid': openid, 'error': err}]}

    @classmethod
    def SendBatch(cls, openids, template_id=None, data=None, url=''):
        """批量发送（同一模板与数据），分批防限流。"""
        openids = list(openids or [])
        template_id = template_id or cls._DefaultTemplateId()
        if not template_id:
            raise RuntimeError('[Broadcast] 未指定 template_id 且未配置默认模板')
        success = 0
        fail = 0
        errors = []
        if not openids:
            return {'success': 0, 'fail': 0, 'errors': []}
        batch_size = cls._BatchSize()
        try:
            token = AccessToken.Get('official')
        except Exception as e:
            logger.error('[Broadcast] 获取 access_token 失败: %s', e, exc_info=True)
            return {
                'success': 0,
                'fail': len(openids),
                'errors': [{'openid': oid, 'error': str(e)} for oid in openids],
            }
        for idx, openid in enumerate(openids):
            if not openid:
                fail += 1
                errors.append({'openid': openid, 'error': 'openid 为空'})
                continue
            payload = {
                'touser': openid,
                'template_id': template_id,
                'url': url or '',
                'data': data or {},
            }
            ok, err = cls._Post(token, payload)
            if ok:
                success += 1
            else:
                fail += 1
                errors.append({'openid': openid, 'error': err})
            if (idx + 1) % batch_size == 0 and idx + 1 < len(openids):
                time.sleep(_BATCH_INTERVAL)
        return {'success': success, 'fail': fail, 'errors': errors}

    @classmethod
    def BroadcastAll(cls, openids, template_id=None, data=None):
        """按订阅用户广播（SendBatch 的语义化别名）。"""
        return cls.SendBatch(openids, template_id=template_id, data=data, url='')

    @classmethod
    def _Post(cls, token, payload):
        """实际调用微信发送接口。返回 (ok, error_msg)。"""
        try:
            import requests
            resp = requests.post(
                _TEMPLATE_SEND_URL,
                params={'access_token': token},
                json=payload,
                timeout=10,
            )
            result = resp.json()
        except Exception as e:
            logger.error('[Broadcast] 请求微信失败: %s', e, exc_info=True)
            return False, f'请求异常: {e}'
        errcode = result.get('errcode', 0)
        if errcode == 0:
            return True, ''
        errmsg = result.get('errmsg', 'unknown')
        logger.warning('[Broadcast] 发送失败 errcode=%s errmsg=%s', errcode, errmsg)
        if errcode in _INVALID_TOKEN_CODES:
            cls._InvalidateToken()
        return False, f'{errcode}: {errmsg}'

    @staticmethod
    def _InvalidateToken():
        """token 失效时清缓存以便下次刷新。"""
        try:
            appid = AccessToken._GetConfig('official')[0]
            cache.delete(AccessToken._CacheKey('official', appid))
        except Exception:
            logger.warning('[Broadcast] 清除 token 缓存失败', exc_info=True)