from fastapi import APIRouter, Depends
from sqlalchemy.orm import Session
from typing import List, Optional
from app.models.coupon import (
    CouponDB, 
    UserCouponDB, 
    CouponCreate, 
    CouponUpdate,
    CouponInfo,
    UserCouponCreate,
    UserCouponInfo,
    CouponStatus
)
from app.models.database import get_db
from app.api.deps import get_admin_user, get_current_user
from app.models.user import UserDB
from app.core.response import success_response, error_response, ResponseModel
from datetime import datetime, timezone

router = APIRouter()

@router.post("/", response_model=ResponseModel)
async def create_coupon(
    coupon: CouponCreate,
    db: Session = Depends(get_db),
    admin: UserDB = Depends(get_admin_user)
):
    """创建优惠券（管理员）"""
    db_coupon = CouponDB(**coupon.model_dump())
    db.add(db_coupon)
    
    try:
        db.commit()
        db.refresh(db_coupon)
        return success_response(data=CouponInfo.model_validate(db_coupon))
    except Exception as e:
        db.rollback()
        return error_response(code=500, message=f"创建优惠券失败: {str(e)}")

@router.put("/{coupon_id}", response_model=ResponseModel)
async def update_coupon(
    coupon_id: int,
    coupon: CouponUpdate,
    db: Session = Depends(get_db),
    admin: UserDB = Depends(get_admin_user)
):
    """更新优惠券（管理员）"""
    db_coupon = db.query(CouponDB).filter(CouponDB.id == coupon_id).first()
    if not db_coupon:
        return error_response(code=404, message="优惠券不存在")
    
    update_data = coupon.model_dump(exclude_unset=True)
    for key, value in update_data.items():
        setattr(db_coupon, key, value)
    
    try:
        db.commit()
        db.refresh(db_coupon)
        return success_response(data=CouponInfo.model_validate(db_coupon))
    except Exception as e:
        db.rollback()
        return error_response(code=500, message=f"更新优惠券失败: {str(e)}")

@router.post("/issue", response_model=ResponseModel)
async def issue_coupon(
    user_coupon: UserCouponCreate,
    db: Session = Depends(get_db),
    admin: UserDB = Depends(get_admin_user)
):
    """发放优惠券给用户（管理员）"""
    # 查询优惠券信息
    coupon = db.query(CouponDB).filter(CouponDB.id == user_coupon.coupon_id).first()
    if not coupon:
        return error_response(code=404, message="优惠券不存在")
    
    issued_coupons = []
    # 批量创建用户优惠券
    for _ in range(user_coupon.count):
        db_user_coupon = UserCouponDB(
            user_id=user_coupon.user_id,
            coupon_id=coupon.id,
            coupon_name=coupon.name,
            coupon_amount=coupon.amount,
            expire_time=user_coupon.expire_time
        )
        db.add(db_user_coupon)
        issued_coupons.append(db_user_coupon)
    
    try:
        db.commit()
        return success_response(
            message=f"成功发放 {user_coupon.count} 张优惠券",
            data=[UserCouponInfo.model_validate(c) for c in issued_coupons]
        )
    except Exception as e:
        db.rollback()
        return error_response(code=500, message=f"发放优惠券失败: {str(e)}")

@router.get("/user/list", response_model=ResponseModel)
async def get_user_coupons(
    skip: int = 0,
    limit: int = 10,
    status: Optional[CouponStatus] = None,
    db: Session = Depends(get_db),
    current_user: UserDB = Depends(get_current_user)
):
    """获取用户的优惠券列表"""
    query = db.query(UserCouponDB).filter(
        UserCouponDB.user_id == current_user.userid
    )
    
    # 如果指定了状态，添加状态过滤
    if status:
        query = query.filter(UserCouponDB.status == status)
    
    # 更新过期状态
    now = datetime.now(timezone.utc)
    db.query(UserCouponDB).filter(
        UserCouponDB.user_id == current_user.userid,
        UserCouponDB.status == CouponStatus.UNUSED,
        UserCouponDB.expire_time < now
    ).update({"status": CouponStatus.EXPIRED})
    
    db.commit()
    
    # 获取分页数据
    coupons = query.order_by(
        UserCouponDB.create_time.desc()
    ).offset(skip).limit(limit).all()
    
    return success_response(
        data=[UserCouponInfo.model_validate(c) for c in coupons]
    )

@router.get("/list", response_model=ResponseModel)
async def get_all_coupons(
    skip: int = 0,
    limit: int = 10,
    db: Session = Depends(get_db)
):
    """获取所有优惠券列表（管理员）"""
    coupons = db.query(CouponDB).order_by(
        CouponDB.create_time.desc()
    ).offset(skip).limit(limit).all()
    
    return success_response(
        data=[CouponInfo.model_validate(c) for c in coupons]
    )