"""
合同相关定时任务
"""
from datetime import datetime, timedelta
from sqlalchemy import create_engine, select
from sqlalchemy.orm import Session
from alien_gateway.config import settings
from alien_contract.db.models.bundle import ContractBundle
from alien_contract.db.models.document import ContractDocument
from alien_util.celery_app import celery_app
from common.aliyun_sms_server.sms_client import send_sms
import logging

# 配置日志
logger = logging.getLogger(__name__)
logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s [%(levelname)s] %(name)s %(message)s"
)


# 全局数据库引擎（避免重复创建）
_sync_engine = None

def get_sync_db_session():
    """
    获取同步数据库会话（用于 Celery 任务）
    Celery 任务通常使用同步代码，所以需要同步数据库连接
    """
    global _sync_engine
    if _sync_engine is None:
        # 使用同步数据库连接
        database_url = settings.SQLALCHEMY_DATABASE_URI
        _sync_engine = create_engine(
            database_url,
            pool_pre_ping=True,
            pool_size=5,
            max_overflow=10
        )
    return Session(_sync_engine)


@celery_app.task(name="alien_util.tasks.contract_tasks.check_contract_expiry")
def check_contract_expiry(subject_type: str | None = "store"):
    """
    检查合同到期时间，如果距离到期不足15天，发送提醒短信
    每天凌晨0点1分执行

    :param subject_type: 签约主体类型过滤，默认 "store"（仅商家）；传 None 则不过滤(store+lawyer 全部)
    """
    logger.info("开始执行合同到期检查任务 subject_type=%s", subject_type)
    
    try:
        # 获取数据库会话
        db = get_sync_db_session()
        
        try:
            now = datetime.now()
            # 计算15天后的日期
            check_date = now + timedelta(days=15)

            # 合同中心：仅对"主合同(is_primary=1) 且 已签署(status=1)"发提醒，
            # 避免同一合同包内多份子合同（支付宝授权函/微信承诺函等）重复发送
            conditions = [
                ContractDocument.is_primary == 1,
                ContractDocument.status == 1,
                ContractDocument.expiry_time.isnot(None),
                ContractDocument.expiry_time <= check_date,
                ContractDocument.expiry_time >= now,
                ContractDocument.delete_flag == 0,
                ContractBundle.delete_flag == 0,
            ]
            if subject_type:
                conditions.append(ContractBundle.subject_type == subject_type)

            stmt = (
                select(
                    ContractDocument.id,
                    ContractDocument.expiry_time,
                    ContractBundle.subject_name,
                    ContractBundle.contact_phone,
                    ContractBundle.subject_type,
                )
                .join(ContractBundle, ContractDocument.bundle_id == ContractBundle.id)
                .where(*conditions)
            )

            contracts = db.execute(stmt).all()

            logger.info(f"找到 {len(contracts)} 条即将到期的合同")

            # 遍历即将到期的合同，发送提醒短信
            for contract in contracts:
                try:
                    # 计算距离到期的天数
                    days_until_expiry = (contract.expiry_time - now).days

                    logger.info(
                        f"合同文档ID: {contract.id}, "
                        f"主体类型: {contract.subject_type}, "
                        f"主体名称: {contract.subject_name}, "
                        f"联系电话: {contract.contact_phone}, "
                        f"到期时间: {contract.expiry_time}, "
                        f"距离到期: {days_until_expiry} 天"
                    )

                    send_expiry_reminder_sms(
                        contract.contact_phone,
                        contract.subject_name,
                        settings.ALIYUN_SMS_SIGN_NAME_CONTRACT,
                        settings.ALIYUN_SMS_TEMPLATE_CODE_CONTRACT,
                    )
                except Exception as e:
                    logger.error(f"处理合同文档ID {contract.id} 时出错: {e}", exc_info=True)
            
            logger.info("合同到期检查任务执行完成")
            
        finally:
            db.close()
            
    except Exception as e:
        logger.error(f"执行合同到期检查任务时出错: {e}", exc_info=True)
        raise


def send_expiry_reminder_sms(phone: str, merchant_name: str, sign_name: str, template_code: str):
    """
    发送合同到期提醒短信
    Args:
        phone: 联系电话
        merchant_name: 商家名称
        days_until_expiry: 距离到期的天数
    """
    template_param = {
        "name": merchant_name,
    }
    send_sms(phone, template_param, sign_name, template_code)