# app/services/order_service.py
import uuid
import json
from datetime import datetime, timedelta
from typing import List, Optional

from redis.asyncio import Redis
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select

from app.utils.search import apply_keyword_search_stmt
from app.utils.pagination import paginate
from app.core.biz_exception import NotFoundError, BizLogicError
from app.models.user import VasUser
from app.models.order import VasOrder
from app.models.vas_task import VasTask
from app.models.product import VasProduct
from app.models.payment import VasPayment
from app.models.product_routing import VasProductRouting
from app.schemas.order import VasOrderCreate, VasOrderAdjustPrice, VasOrderPatchUserInputs
from app.services.webhook_service import WebhookService


class OrderService:

    @staticmethod
    async def create(
        db: AsyncSession,
        data: VasOrderCreate,
        product: VasProduct,
        auth_user: VasUser,
        redis_client: Redis,
    ) -> VasOrder:

        if not auth_user.email:
            raise BizLogicError(
                "Your account must be linked to an email address before you can place an order."
            )

        order_id = f"ORD-{datetime.utcnow():%Y%m%d%H%M%S}-{uuid.uuid4().hex[:8]}"

        order = VasOrder(
            id=order_id,
            **data.dict(),
            product_name=product.title,
            base_amount=product.price_amount,
            base_currency=product.price_currency,
            adjustment_delta=0,
            final_amount=product.price_amount,
            user_id=auth_user.id,
        )

        db.add(order)
        await db.commit()
        await db.refresh(order)

        return order
    
    @staticmethod
    async def cancel(
        db: AsyncSession,
        order_id,
    ) -> VasOrder:
        stmt = select(VasOrder).where(VasOrder.id == order_id)
        order = (await db.execute(stmt)).scalar_one_or_none()

        if not order:
            raise NotFoundError("Order not exist")
        
        order.status = "closed"
        task_res = await db.execute(
            select(VasTask).where(
                VasTask.order_id == order.id,
                VasTask.status.in_(["pending", "grabbed", "running", "completed"]),
            )
        )
        for task in task_res.scalars().all():
            task.status = "cancelled"
            
        await db.commit()
        await db.refresh(order)
        return order
    
    @staticmethod
    async def create_by_admin(
        db: AsyncSession,
        data: VasOrderCreate,
        product: VasProduct,
        auth_user: VasUser
    ) -> VasOrder:
        order_id = f"ORD-{datetime.utcnow():%Y%m%d%H%M%S}-{uuid.uuid4().hex[:8]}"
        order = VasOrder(
            id=order_id,
            **data.dict(),
            status="paid",
            product_name=product.title,
            base_amount=product.price_amount,
            base_currency=product.price_currency,
            adjustment_delta=0,
            final_amount=product.price_amount,
            user_id=auth_user.id,
        )
        # ===== user_inputs 安全修复 =====
        raw_inputs = order.user_inputs

        if isinstance(raw_inputs, str):
            try:
                order.user_inputs = json.loads(raw_inputs)
            except Exception:
                order.user_inputs = {}
        elif raw_inputs is None or not isinstance(raw_inputs, dict):
            order.user_inputs = {}

        order.user_inputs["_admin_bypass"] = {
            "enabled": True,
            "by": auth_user.id,
            "at": datetime.utcnow().isoformat(),
            "reason": "admin manual order",
        }
        
        db.add(order)
        
        await WebhookService._create_task_if_not_exists(db, order)
        
        await db.commit()
        await db.refresh(order)
        return order
    
    @staticmethod
    async def adjust_order_price(db: AsyncSession, order_id: str,  payload: VasOrderAdjustPrice) -> VasOrder:
        stmt = select(VasOrder).where(VasOrder.id == order_id)
        order = (await db.execute(stmt)).scalar_one_or_none()

        if not order:
            raise NotFoundError("Order not exist")

        if order.status != "pending":
            raise BizLogicError(message="Order not adjustable")

        # 2. 更新订单价格
        order.adjustment_delta = payload.adjustment_delta
        order.final_amount = order.base_amount + payload.adjustment_delta

        if order.final_amount <= 0:
            raise BizLogicError(message="final_amount must be > 0")

        # ② 是否已有 pending payment（幂等）
        stmt = select(VasPayment).where(
            VasPayment.order_id == order.id,
            VasPayment.status == "pending",
        )
        active_payment = (await db.execute(stmt)).scalar_one_or_none()

        if active_payment:
            active_payment.status = "expired"

        await db.commit()
        await db.refresh(order)
        return order

    @staticmethod
    async def get(db: AsyncSession, order_id: str) -> Optional[VasOrder]:
        stmt = select(VasOrder).where(VasOrder.id == order_id)
        return (await db.execute(stmt)).scalar_one_or_none()

    @staticmethod
    async def list_by_user(
        db: AsyncSession,
        user_id: str,
        page: int = 0,
        size: int = 10,
        keyword: Optional[str] = None,
    ):
        stmt = select(VasOrder).where(VasOrder.user_id == user_id)
        stmt = apply_keyword_search_stmt(
            stmt=stmt,
            model=VasOrder,
            keyword=keyword,
            fields=["id", "user_id", "product_name", "user_inputs"],
        ).order_by(VasOrder.created_at.desc())

        return await paginate(db, stmt, page, size)

    @staticmethod
    async def list_all(
        db: AsyncSession,
        page: int = 0,
        size: int = 10,
        keyword: Optional[str] = None,
    ):
        stmt = select(VasOrder)
        query = apply_keyword_search_stmt(
            stmt=stmt,
            model=VasOrder,
            keyword=keyword,
            fields=["id", "user_id", "user_name", "product_name", "user_inputs"],
        ).order_by(VasOrder.created_at.desc())

        return await paginate(db, query, page, size)

    @staticmethod
    async def patch_user_inputs(
        db: AsyncSession,
        order_id: str,
        payload: VasOrderPatchUserInputs,
    ) -> VasOrder:

        stmt = select(VasOrder).where(VasOrder.id == order_id)
        order = (await db.execute(stmt)).scalar_one_or_none()

        if not order:
            raise NotFoundError("Order not exist")

        order.user_inputs = payload.user_inputs
        

        # 1️⃣ 取消旧任务
        task_res = await db.execute(
            select(VasTask).where(
                VasTask.order_id == order.id,
                VasTask.status.in_(["pending", "grabbed", "running", "completed"]),
            )
        )
        for task in task_res.scalars().all():
            task.status = "cancelled"
        
        await db.flush()
        await WebhookService._create_task_if_not_exists(db, order)
        
        
        await db.commit()
        await db.refresh(order)

        return order