"""
购物车视图
"""
from flask import Blueprint, render_template, request, jsonify, session, redirect, url_for, flash
from app.models.cart import Cart
from app.models.product import Product, ProductInventory
from app.models.user import User
from app.utils.decorators import login_required
from config.database import db

cart_bp = Blueprint('cart', __name__, url_prefix='/cart')


@cart_bp.route('/')
@login_required
def index():
    """购物车页面"""
    user_id = session['user_id']
    cart_items = Cart.get_user_cart(user_id)

    # 计算总价和可用商品数量
    total_price = 0
    available_count = 0

    for item in cart_items:
        if item.is_available():
            total_price += item.get_total_price()
            available_count += 1

    return render_template('cart/index.html',
                         cart_items=cart_items,
                         total_price=total_price,
                         available_count=available_count)


@cart_bp.route('/add', methods=['POST'])
@login_required
def add():
    """添加商品到购物车"""
    try:
        user_id = session['user_id']
        product_id = request.json.get('product_id')
        sku_code = request.json.get('sku_code')
        spec_combination = request.json.get('spec_combination', '')
        quantity = request.json.get('quantity', 1)

        # 验证参数
        if not product_id or quantity <= 0:
            return jsonify({'success': False, 'message': '参数错误'})

        # 检查商品是否存在且上架
        product = Product.query.filter_by(id=product_id, status=1).first()
        if not product:
            return jsonify({'success': False, 'message': '商品不存在或已下架'})

        # 检查库存
        if sku_code:
            sku_info = ProductInventory.query.filter_by(sku_code=sku_code).first()
            if not sku_info:
                return jsonify({'success': False, 'message': 'SKU不存在'})

            if sku_info.stock < quantity:
                return jsonify({'success': False, 'message': f'库存不足，仅剩{sku_info.stock}件'})
        else:
            # 如果没有指定SKU，检查默认库存
            default_sku = ProductInventory.query.filter_by(
                product_id=product_id,
                is_default=1
            ).first()
            if default_sku and default_sku.stock < quantity:
                return jsonify({'success': False, 'message': f'库存不足，仅剩{default_sku.stock}件'})

        # 添加到购物车
        Cart.add_to_cart(
            user_id=user_id,
            product_id=product_id,
            sku_code=sku_code,
            spec_combination=spec_combination,
            quantity=quantity
        )

        # 获取购物车数量
        cart_count = Cart.get_cart_count(user_id)

        return jsonify({
            'success': True,
            'message': '已添加到购物车',
            'cart_count': cart_count
        })

    except Exception as e:
        db.session.rollback()
        return jsonify({'success': False, 'message': f'添加失败: {str(e)}'})


@cart_bp.route('/update', methods=['POST'])
@login_required
def update():
    """更新购物车商品数量"""
    try:
        user_id = session['user_id']
        cart_id = request.json.get('cart_id')
        quantity = request.json.get('quantity')

        if not cart_id or quantity is None or quantity < 0:
            return jsonify({'success': False, 'message': '参数错误'})

        # 获取购物车项目
        cart_item = Cart.query.filter_by(id=cart_id, user_id=user_id).first()
        if not cart_item:
            return jsonify({'success': False, 'message': '购物车项目不存在'})

        if quantity == 0:
            # 删除商品
            db.session.delete(cart_item)
        else:
            # 检查库存
            if cart_item.get_stock() < quantity:
                return jsonify({
                    'success': False,
                    'message': f'库存不足，仅剩{cart_item.get_stock()}件'
                })

            # 更新数量
            cart_item.quantity = quantity
            cart_item.updated_at = db.func.now()

        db.session.commit()

        # 返回更新后的信息
        cart_count = Cart.get_cart_count(user_id)
        total_price = Cart.get_cart_total(user_id)

        return jsonify({
            'success': True,
            'message': '更新成功',
            'cart_count': cart_count,
            'total_price': total_price,
            'item_total': cart_item.get_total_price() if quantity > 0 else 0
        })

    except Exception as e:
        db.session.rollback()
        return jsonify({'success': False, 'message': f'更新失败: {str(e)}'})


@cart_bp.route('/remove', methods=['POST'])
@login_required
def remove():
    """删除购物车商品"""
    try:
        user_id = session['user_id']
        cart_id = request.json.get('cart_id')

        if not cart_id:
            return jsonify({'success': False, 'message': '参数错误'})

        # 获取购物车项目
        cart_item = Cart.query.filter_by(id=cart_id, user_id=user_id).first()
        if not cart_item:
            return jsonify({'success': False, 'message': '购物车项目不存在'})

        db.session.delete(cart_item)
        db.session.commit()

        # 返回更新后的信息
        cart_count = Cart.get_cart_count(user_id)
        total_price = Cart.get_cart_total(user_id)

        return jsonify({
            'success': True,
            'message': '删除成功',
            'cart_count': cart_count,
            'total_price': total_price
        })

    except Exception as e:
        db.session.rollback()
        return jsonify({'success': False, 'message': f'删除失败: {str(e)}'})


@cart_bp.route('/clear', methods=['POST'])
@login_required
def clear():
    """清空购物车"""
    try:
        user_id = session['user_id']

        Cart.query.filter_by(user_id=user_id).delete()
        db.session.commit()

        return jsonify({
            'success': True,
            'message': '购物车已清空'
        })

    except Exception as e:
        db.session.rollback()
        return jsonify({'success': False, 'message': f'清空失败: {str(e)}'})


@cart_bp.route('/count')
@login_required
def count():
    """获取购物车商品数量"""
    user_id = session['user_id']
    cart_count = Cart.get_cart_count(user_id)
    return jsonify({'cart_count': cart_count})


@cart_bp.route('/checkout')
@login_required
def checkout():
    """去结算"""
    user_id = session['user_id']
    selected_items = request.args.getlist('items')

    if not selected_items:
        flash('请选择要购买的商品', 'error')
        return redirect(url_for('cart.index'))

    # 获取选中的购物车项目
    cart_items = Cart.query.filter(
        Cart.id.in_(selected_items),
        Cart.user_id == user_id
    ).all()

    if not cart_items:
        flash('选中的商品不存在', 'error')
        return redirect(url_for('cart.index'))

    # 检查商品可用性
    unavailable_items = []
    for item in cart_items:
        if not item.is_available():
            unavailable_items.append(item.product.name)

    if unavailable_items:
        flash(f'以下商品库存不足或已下架：{", ".join(unavailable_items)}', 'error')
        return redirect(url_for('cart.index'))

    # 跳转到订单结算页面
    items_param = '&'.join([f'items={item_id}' for item_id in selected_items])
    return redirect(url_for('order.checkout') + '?' + items_param)