#stock.py
from app.extensions import db
from datetime import datetime


class StockBuy(db.Model):
    __tablename__ = 'stock_buy'

    id = db.Column(db.Integer, primary_key=True)

    # 【核心关联】
    # 这里明确指定了 base_id 是外键，关联 material_base 表的 id
    base_id = db.Column(db.Integer, db.ForeignKey('material_base.id'), nullable=False)

    sku = db.Column(db.String(100))
    in_date = db.Column(db.Date)
    serial_number = db.Column(db.String(100))
    batch_number = db.Column(db.String(100))

    # 数量
    in_quantity = db.Column(db.Numeric(19, 4), default=0)
    stock_quantity = db.Column(db.Numeric(19, 4), default=0)
    available_quantity = db.Column(db.Numeric(19, 4), default=0)

    # 状态与位置
    status = db.Column(db.String(50))
    inspection_status = db.Column(db.String(50))
    warehouse_location = db.Column(db.String(100))

    # 财务与商务
    unit_price = db.Column(db.Numeric(19, 4), default=0)
    total_price = db.Column(db.Numeric(19, 4), default=0)
    currency = db.Column(db.String(20), default='CNY')
    exchange_rate = db.Column(db.Numeric(15, 6), default=1.0)
    supplier_name = db.Column(db.String(255))
    buyer_name = db.Column(db.String(100))
    buyer_email = db.Column(db.String(100))
    original_link = db.Column(db.Text)
    detail_link = db.Column(db.Text)
    arrival_photo = db.Column(db.Text)

    # 【核心关联】
    # 建立对象级别的连接，方便通过 stock.material 访问基础信息
    material = db.relationship('MaterialBase', back_populates='stock_buys')

    def to_dict(self):
        """序列化"""
        return {
            'id': self.id,
            'base_id': self.base_id,  # 前端需要这个ID来判断关联
            'material_name': self.material.name if self.material else None,
            'spec_model': self.material.spec_model if self.material else None,
            'category': self.material.category if self.material else None,
            'unit': self.material.unit if self.material else None,
            'material_type': self.material.material_type if self.material else None,

            'sku': self.sku,
            'inbound_date': self.in_date.strftime('%Y-%m-%d') if self.in_date else None,
            'serial_number': self.serial_number,
            'batch_number': self.batch_number,
            'qty_inbound': float(self.in_quantity) if self.in_quantity else 0,
            'qty_stock': float(self.stock_quantity) if self.stock_quantity else 0,
            'qty_available': float(self.available_quantity) if self.available_quantity else 0,
            'warehouse_loc': self.warehouse_location,
            'status': self.status,
            'price_unit': float(self.unit_price) if self.unit_price else 0,
            'price_total': float(self.total_price) if self.total_price else 0,
            'supplier_name': self.supplier_name
        }