import re
import asyncio
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select, func
from app.core.logger import logger
from app.schemas.order_event import VasOrderEventCreate
from app.services.order_event_service import OrderEventService
from app.services.notification_service import NotificationService
from app.models.order import VasOrder
from app.models.user import VasUser
from app.models.emails import VasEmail
from app.schemas.emails import VasEmailCreate

class EmailsService:
    # 关键词黑名单：匹配到这些词的邮件不会创建订单事件，也不会通知用户
    SUBJECT_BLACKLIST = [
        "验证码",
        "动态码",
        "verification code",
        "otp", 
        "one-time password",
        "security code",
        "dynamic code",
        "one time password"
    ]
    
    SENDER_BLACKLIST = [
        "etsy",
        "dsw",
    ]

    @staticmethod
    def _is_subject_blacklisted(subject: str) -> bool:
        if not subject: return False
        lower = subject.lower()
        return any(kw.lower() in lower for kw in EmailsService.SUBJECT_BLACKLIST)
    
    @staticmethod
    def _is_sender_blacklisted(sender: str) -> bool:
        if not sender: return False
        lower = sender.lower()
        return any(kw.lower() in lower for kw in EmailsService.SENDER_BLACKLIST)

    @staticmethod
    def _summarize(text: str, limit: int = 120) -> str:
        if not text: return ""
        # 将多个空白字符替换为一个空格
        clean = re.sub(r"\s+", " ", text).strip()
        return clean[:limit] + ("..." if len(clean) > limit else "")

    @staticmethod
    async def create(db: AsyncSession, data: VasEmailCreate) -> VasEmail:
        # 1. 检查 UID 是否已存在 (幂等性)
        stmt = select(VasEmail).where(VasEmail.uid == data.uid)
        existing = (await db.execute(stmt)).scalar_one_or_none()
        if existing:
            return existing

        # 2. 存入邮件记录
        rec = VasEmail(
            uid=data.uid,
            subject=data.subject,
            sender=data.sender,
            recipient=data.recipient,
            receive_time=data.receive_time,
            body_text=data.body_text,
        )
        db.add(rec)
        
        # 3. 拦截、匹配订单并入库通知 (此时还在同一个事务中)
        await EmailsService._intercept_and_notify(db, rec)
        
        # 4. 统一提交
        await db.commit()
        await db.refresh(rec)
        
        return rec

    @staticmethod
    async def get_max_uid(db: AsyncSession) -> int:
        stmt = select(func.max(VasEmail.uid))
        return await db.scalar(stmt) or 0

    @staticmethod
    async def _intercept_and_notify(db: AsyncSession, rec: VasEmail) -> None:
        """
        拦截处理逻辑：
        1. 黑名单过滤
        2. 创建订单事件 (OrderEventService)
        3. 获取订单关联的用户联系方式
        4. post_message 到通知表
        """
        if EmailsService._is_subject_blacklisted(rec.subject or ""):
            logger.info(f"Email {rec.uid} skipped: subject '{rec.subject}' is in blacklist.")
            return
        
        if EmailsService._is_sender_blacklisted(rec.sender or ""):
            logger.info(f"Email {rec.uid} skipped: subject '{rec.sender}' is in blacklist.")
            return

        # 1. 尝试创建订单事件 (OrderEventService 内部会根据 rec.recipient 匹配订单)
        try:
            event = await OrderEventService.create(
                db,
                VasOrderEventCreate(
                    order_no=None, # 由 OrderEventService 内部填充
                    alias_email=rec.recipient,
                    event_title=rec.subject or "Email Update",
                    event_message=rec.body_text,
                    email_uid=rec.uid,
                    event_time=None,
                ),
            )
        except Exception as e:
            logger.warning(f"Failed to create order event for email {rec.uid}: {e}")
            return

        # 2. 如果邮件没能关联到任何活跃订单，则不通知
        if not event or not event.order_no:
            logger.info(f"Email {rec.uid} logged, but no matching active order found for {rec.recipient}.")
            return

        # 3. 获取订单及用户信息
        stmt = select(VasOrder).where(VasOrder.id == event.order_no)
        order = (await db.execute(stmt)).scalar_one_or_none()
        if not order:
            return

        user = await db.get(VasUser, order.user_id)
        user_inputs = order.user_inputs or {}

        # 优先级：数据库用户字段 > 订单输入的联系方式
        email_to = (user.email if user else None) or user_inputs.get("email")
        # phone = (user.phone if user else None) or user_inputs.get("phone")
        # country_code = str(user_inputs.get("phone_country_code") or "")

        # 4. 构造通知内容
        summary = EmailsService._summarize(rec.body_text or "")
        
        # --- 邮件转发任务 ---
        if email_to:
            subject = f"Update: {rec.subject or 'Visa Appointment Progress'}"
            await NotificationService.post_message(
                db=db,
                channel="email",
                payload={
                    "template_id": "order_event_update",
                    "receiver": email_to,
                    "payload": {
                        "subject": subject,
                        "summary": summary,
                        "order_no": order.id,
                    },
                },
            )

        # --- WhatsApp 推送任务 ---
        # if phone:
        #     # 确保国家代码不带 +
        #     code = str(user_inputs.get("phone_country_code") or "").replace("+", "")
        #     # 去掉手机号开头的 0
        #     clean_phone = str(phone).lstrip('0')
            
        #     # 组合纯数字部分
        #     digits = f"{code}{clean_phone}"
        #     # 再次利用正则确保只剩数字（以防 code 包含特殊字符）
        #     digits = re.sub(r"\D", "", digits)

        #     if "@lid" in str(phone):
        #         chat_id = phone
        #     elif digits:
        #         # 使用不带 + 的纯数字拼接后缀
        #         chat_id = f"{digits}@c.us"
        #     else:
        #         return

        #     message = (
        #         f"🔔 *Progress Update*\n\n"
        #         f"We received an update for your appointment:\n"
        #         f"_{summary}_\n\n"
        #         f"Please log in to your dashboard or check your email for full details."
        #     )

        #     await NotificationService.post_message(
        #         db=db,
        #         channel="whatsapp",
        #         payload={
        #             "template_id": "order_event_update",
        #             "receiver": chat_id,
        #             "payload": {
        #                 "message": message,
        #                 "order_no": order.id,
        #             },
        #         },
        #     )
            
        logger.info(f"Notification tasks queued for Email {rec.uid} (Order: {order.id})")