from fastapi import APIRouter, Depends
from sqlalchemy.orm import Session
from typing import List, Optional
from sqlalchemy import text
from app.models.merchant import (
    MerchantDB,
    MerchantCreate,
    MerchantUpdate,
    MerchantInfo,
    MerchantImageDB
)
from app.models.database import get_db
from app.api.deps import get_admin_user
from app.models.user import UserDB
from app.core.response import success_response, error_response, ResponseModel

router = APIRouter()

@router.post("", response_model=ResponseModel)
async def create_merchant(
    merchant: MerchantCreate,
    db: Session = Depends(get_db),
    admin: UserDB = Depends(get_admin_user)
):
    """创建商家（管理员）"""
    # 创建商家基本信息
    merchant_data = merchant.model_dump(exclude={'images'})
    db_merchant = MerchantDB(**merchant_data)
    db.add(db_merchant)
    
    try:
        db.flush()  # 获取商家ID
        
        # 创建商家图片
        for image in merchant.images:
            db_image = MerchantImageDB(
                merchant_id=db_merchant.id,
                image_url=image.image_url,
                sort=image.sort
            )
            db.add(db_image)
        
        db.commit()
        db.refresh(db_merchant)
        return success_response(data=MerchantInfo.model_validate(db_merchant))
    except Exception as e:
        db.rollback()
        return error_response(code=500, message=f"创建失败: {str(e)}")

@router.put("/{merchant_id}", response_model=ResponseModel)
async def update_merchant(
    merchant_id: int,
    merchant: MerchantUpdate,
    db: Session = Depends(get_db),
    admin: UserDB = Depends(get_admin_user)
):
    """更新商家信息（管理员）"""
    db_merchant = db.query(MerchantDB).filter(
        MerchantDB.id == merchant_id
    ).first()
    
    if not db_merchant:
        return error_response(code=404, message="商家不存在")
    
    # 更新基本信息
    update_data = merchant.model_dump(exclude={'images'}, exclude_unset=True)
    for key, value in update_data.items():
        setattr(db_merchant, key, value)
    
    # 如果更新了图片
    if merchant.images is not None:
        # 删除原有图片
        db.query(MerchantImageDB).filter(
            MerchantImageDB.merchant_id == merchant_id
        ).delete()
        
        # 添加新图片
        for image in merchant.images:
            db_image = MerchantImageDB(
                merchant_id=merchant_id,
                image_url=image.image_url,
                sort=image.sort
            )
            db.add(db_image)
    
    try:
        db.commit()
        db.refresh(db_merchant)
        return success_response(data=MerchantInfo.model_validate(db_merchant))
    except Exception as e:
        db.rollback()
        return error_response(code=500, message=f"更新失败: {str(e)}")

@router.get("/{merchant_id}", response_model=ResponseModel)
async def get_merchant(
    merchant_id: int,
    db: Session = Depends(get_db)
):
    """获取商家详情"""
    merchant = db.query(MerchantDB).filter(
        MerchantDB.id == merchant_id
    ).first()
    
    if not merchant:
        return error_response(code=404, message="商家不存在")
    
    return success_response(data=MerchantInfo.model_validate(merchant))

@router.get("", response_model=ResponseModel)
async def list_merchants(
    longitude: Optional[float] = None,
    latitude: Optional[float] = None,
    skip: int = 0,
    limit: int = 20,
    db: Session = Depends(get_db)
):
    """获取商家列表，如果提供经纬度则按距离排序，否则按创建时间排序"""
    if longitude is not None and latitude is not None:
        # 使用 MySQL 的 ST_Distance_Sphere 计算距离（单位：米）
        merchants = db.query(
            MerchantDB,
            text("ST_Distance_Sphere(point(longitude, latitude), point(:lon, :lat)) as distance")
        ).params(
            lon=longitude,
            lat=latitude
        ).order_by(
            text("distance")
        ).offset(skip).limit(limit).all()
        
        return success_response(data=[{
            **MerchantInfo.model_validate(m[0]).model_dump(),
            "distance": round(m[1])  # 四舍五入到整数米
        } for m in merchants])
    else:
        # 如果没有提供经纬度，按创建时间排序
        merchants = db.query(MerchantDB).order_by(
            MerchantDB.create_time.desc()
        ).offset(skip).limit(limit).all()
      
        return success_response(data=[
            MerchantInfo.model_validate(m) for m in merchants
        ])