# app/services/ticket_service.py
from datetime import datetime
from redis.asyncio import Redis
from typing import List
from sqlalchemy.orm import Session
from app.utils.search import apply_keyword_search
from app.utils.pagination import paginate
from app.core.biz_exception import NotFoundError, PermissionDeniedError, BizLogicError
from app.models.user import VasUser
from app.models.ticket import VasTicket
from app.models.ticket_message import VasTicketMessage
from app.schemas.ticket import VasTicketCreate
from app.services.notification_service import NotificationService


class TicketService:
    
    @staticmethod
    def create(db: Session, data: VasTicketCreate, current_user: VasUser, redis_client: Redis):
        rec = VasTicket(**data.dict(), status='pending', created_at=datetime.utcnow())
        rec.user_id = current_user.id
        db.add(rec)
        db.commit()
        db.refresh(rec)
        print(f"📧 send ticket created notification email")
        NotificationService.create(
            redis_client=redis_client,
            ntype="ticket created",
            user_id=current_user.id,
            channels=["email"],
            template_id="ticket_created",
            payload={
                "ticket_id": rec.id,
                "order_id": rec.order_id
            }
        )
        return rec

    @staticmethod
    def update_status(db: Session, ticket_id, status, comment, admin_id):
        ticket = db.query(VasTicket).filter_by(id=ticket_id).first()
        if not ticket:
            raise NotFoundError("Ticket not exist")
        ticket.status = status
        ticket.admin_comment = comment
        db.add(
            VasTicketMessage(
                ticket_id=ticket_id,
                sender_type="admin",
                sender_id=admin_id,
                content=comment
            )
        )
        db.commit()
        db.refresh(ticket)
        return ticket
        
    @staticmethod
    def add_message(
        db: Session,
        ticket_id: int,
        sender_type: str,   # "user" | "admin" | "system"
        sender_id: str = None,
        content: str = "",
        attachments: dict = None
    ):
        # 1️⃣ 校验工单是否存在
        ticket = db.query(VasTicket).filter(
            VasTicket.id == ticket_id
        ).first()

        if not ticket:
            raise NotFoundError("Ticket not exist")

        # 2️⃣ 创建消息
        message = VasTicketMessage(
            ticket_id=ticket_id,
            sender_type=sender_type,
            sender_id=sender_id,
            content=content,
            attachments=attachments,
            created_at=datetime.utcnow()
        )

        # 3️⃣ 写入数据库
        db.add(message)

        # 4️⃣ 更新工单更新时间（非常重要）
        ticket.updated_at = datetime.utcnow()

        db.commit()
        db.refresh(message)

        return message
    
    @staticmethod
    def list_messages(
        db: Session,
        ticket_id: int,
        page: int = 1,
        size: int = 20
    ):
        # 1️⃣ 校验 ticket 是否存在
        exists = db.query(VasTicket.id).filter(
            VasTicket.id == ticket_id
        ).first()

        if not exists:
            raise NotFoundError("Ticket not exist")

        # 2️⃣ 查询消息（按时间正序）
        query = (
            db.query(VasTicketMessage)
            .filter(VasTicketMessage.ticket_id == ticket_id)
            .order_by(VasTicketMessage.created_at.desc())
        )

        return paginate(query, page, size)
    
    @staticmethod
    def list_by_user(db: Session, user_id: str, page: int=0, size: int=10, keyword: str=None):    
        query = db.query(VasTicket).filter_by(user_id=user_id)
        
        query = apply_keyword_search(
            query=query,
            model=VasTicket,
            keyword=keyword,
            fields=["order_id", "user_id", "reason", "admin_comment"]
        )
        query = query.order_by(
            VasTicket.id.desc()
        )
        return paginate(query, page, size)  
      
    @staticmethod
    def list_all(db: Session, page: int=0, size: int=10, keyword: str=None):    
        query = db.query(VasTicket)
        
        query = apply_keyword_search(
            query=query,
            model=VasTicket,
            keyword=keyword,
            fields=["order_id", "user_id", "reason", "admin_comment"]
        )
        query = query.order_by(
            VasTicket.id.desc()
        )
        return paginate(query, page, size)