"""物料入库/出库系统 - 数据模型 (SQLAlchemy 2.0)

实体:
  User        账号(admin / manager / operator)
  Material    物料主数据
  Inbound     入库流水(含"期初"来源的首笔)
  Outbound    出库流水(含生产领用)
  Bom         BOM 清单(产品型号)
  BomItem     BOM 组成(某物料单套用量)
  ProdOrder   生产订单(接单量) -> 按 BOM 展开领料需求
  OperationLog 操作日志(谁/何时/做了什么)

库存口径: 在库 = SUM(入库) - SUM(出库), 由 app 实时聚合, 不冗余存储。
"""
import os
from datetime import datetime, date
from flask_sqlalchemy import SQLAlchemy
from sqlalchemy import UniqueConstraint

db = SQLAlchemy()


class User(db.Model):
    __tablename__ = "user"
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(64), unique=True, nullable=False, index=True)
    password = db.Column(db.String(128), nullable=False)  # sha256 hex
    role = db.Column(db.String(32), default="operator")   # admin / manager / operator
    display_name = db.Column(db.String(64), default="")
    active = db.Column(db.Boolean, default=True)


class Material(db.Model):
    __tablename__ = "material"
    id = db.Column(db.Integer, primary_key=True)
    part_number = db.Column(db.String(64), unique=True, nullable=False, index=True)
    manufacturer = db.Column(db.String(255), default="")   # 型号 / 规格
    unit = db.Column(db.String(16), default="个")
    safety_stock = db.Column(db.Float, default=0)          # 安全库存
    note = db.Column(db.String(255), default="")
    created_at = db.Column(db.DateTime, default=datetime.now)


class Inbound(db.Model):
    __tablename__ = "inbound"
    id = db.Column(db.Integer, primary_key=True)
    material_id = db.Column(db.Integer, db.ForeignKey("material.id"), nullable=False, index=True)
    factory_id = db.Column(db.Integer, db.ForeignKey("factory.id"), nullable=True, index=True)  # 所属工厂/仓库
    batch_no = db.Column(db.String(64), default="")        # 批次号
    qty = db.Column(db.Float, nullable=False)              # 入库数量(正)
    operator = db.Column(db.String(64), default="")        # 经手人
    source = db.Column(db.String(255), default="")         # 来源 / 供应商
    order_ref = db.Column(db.String(64), default="")       # 关联生产单号 / 调拨单号
    occur_date = db.Column(db.Date, default=date.today)
    delivery_date = db.Column(db.Date, default=None)        # 送货日期(供应商到货日, 可空)
    remark = db.Column(db.String(255), default="")
    created_at = db.Column(db.DateTime, default=datetime.now)


class Outbound(db.Model):
    __tablename__ = "outbound"
    id = db.Column(db.Integer, primary_key=True)
    material_id = db.Column(db.Integer, db.ForeignKey("material.id"), nullable=False, index=True)
    factory_id = db.Column(db.Integer, db.ForeignKey("factory.id"), nullable=True, index=True)  # 所属工厂/仓库
    batch_no = db.Column(db.String(64), default="")        # 批次号
    qty = db.Column(db.Float, nullable=False)              # 出库数量(正)
    operator = db.Column(db.String(64), default="")        # 经手人
    purpose = db.Column(db.String(255), default="")        # 用途
    order_ref = db.Column(db.String(64), default="")       # 关联生产单号
    occur_date = db.Column(db.Date, default=date.today)
    remark = db.Column(db.String(255), default="")
    created_at = db.Column(db.DateTime, default=datetime.now)


# ---------------- M2: BOM 与生产订单 ----------------
class Bom(db.Model):
    __tablename__ = "bom"
    id = db.Column(db.Integer, primary_key=True)
    code = db.Column(db.String(64), unique=True, nullable=False, index=True)  # BOM 型号简码
    name = db.Column(db.String(255), default="")
    note = db.Column(db.String(255), default="")
    created_at = db.Column(db.DateTime, default=datetime.now)


class BomItem(db.Model):
    __tablename__ = "bom_item"
    id = db.Column(db.Integer, primary_key=True)
    bom_id = db.Column(db.Integer, db.ForeignKey("bom.id"), nullable=False, index=True)
    material_id = db.Column(db.Integer, db.ForeignKey("material.id"), nullable=False, index=True)
    qty_per_unit = db.Column(db.Float, nullable=False, default=0)   # 单套用量


class ProdOrder(db.Model):
    __tablename__ = "prod_order"
    id = db.Column(db.Integer, primary_key=True)
    order_no = db.Column(db.String(64), unique=True, nullable=False, index=True)
    bom_id = db.Column(db.Integer, db.ForeignKey("bom.id"), nullable=False, index=True)
    factory_id = db.Column(db.Integer, db.ForeignKey("factory.id"), nullable=True, index=True)  # 生产工厂/车间
    qty = db.Column(db.Float, nullable=False, default=0)            # 接单量(台/套)
    status = db.Column(db.String(32), default="planned")            # planned / picked / closed
    operator = db.Column(db.String(64), default="")
    remark = db.Column(db.String(255), default="")
    created_at = db.Column(db.DateTime, default=datetime.now)


class ProdOrderAlloc(db.Model):
    """生产订单「调入数量」手动录入: 每个物料的调入计划与已入账标记。

    - alloc_qty: 该物料计划调入(转入)生产工厂的数量, 由用户在订单详情页手动填写。
    - posted:   是否已据此生成入库流水(调入工厂物料)。生成后该行只读, 避免重复入账。
    """
    __tablename__ = "prod_order_alloc"
    id = db.Column(db.Integer, primary_key=True)
    order_id = db.Column(db.Integer, db.ForeignKey("prod_order.id"), nullable=False, index=True)
    material_id = db.Column(db.Integer, db.ForeignKey("material.id"), nullable=False, index=True)
    alloc_qty = db.Column(db.Float, default=0)        # 调入数量(手动录入)
    posted = db.Column(db.Boolean, default=False)     # 是否已生成入库流水
    created_at = db.Column(db.DateTime, default=datetime.now)


class Substitute(db.Model):
    """替代料关系: 某主料(main)可由某替代料(sub)替代使用。

    - 仅描述"谁可替代谁"的参考关系, 不直接参与库存计算。
    - 用于出库 / BOM 领料时, 若主料库存不足, 自动提示可用的替代料。
    - 唯一约束 (main_id, sub_id), 避免重复登记; main 与 sub 不可相同。
    """
    __tablename__ = "substitute"
    id = db.Column(db.Integer, primary_key=True)
    main_id = db.Column(db.Integer, db.ForeignKey("material.id"), nullable=False, index=True)
    sub_id = db.Column(db.Integer, db.ForeignKey("material.id"), nullable=False, index=True)
    note = db.Column(db.String(255), default="")
    created_at = db.Column(db.DateTime, default=datetime.now)
    __table_args__ = (UniqueConstraint("main_id", "sub_id", name="uq_sub_main_sub"),)


# ---------------- M3: 操作日志 ----------------
class OperationLog(db.Model):
    __tablename__ = "operation_log"
    id = db.Column(db.Integer, primary_key=True)
    operator = db.Column(db.String(64), default="")
    action = db.Column(db.String(64), default="")     # 动作分类
    target = db.Column(db.String(255), default="")    # 对象
    detail = db.Column(db.String(512), default="")    # 详情
    created_at = db.Column(db.DateTime, default=datetime.now)


# ---------------- M2-1: 多工厂 / 代工厂 ----------------
class Factory(db.Model):
    __tablename__ = "factory"
    id = db.Column(db.Integer, primary_key=True)
    code = db.Column(db.String(32), unique=True, nullable=False, index=True)  # 工厂编码, 如 SELF / SUB01
    name = db.Column(db.String(128), default="")                              # 工厂名称
    type = db.Column(db.String(16), default="self")                           # self 自厂 / subcontract 代工厂
    enabled = db.Column(db.Boolean, default=True)                             # 是否启用
    note = db.Column(db.String(255), default="")
    created_at = db.Column(db.DateTime, default=datetime.now)


# ---------------- M2-2: 厂间调拨 ----------------
class Transfer(db.Model):
    """厂间调拨: 从源工厂调出、调入目标工厂(同一颗物料)。

    一条调拨记录对应两条流水:
      - Outbound(factory_id=from_factory_id)  : 源厂库存扣减
      - Inbound (factory_id=to_factory_id)    : 目标厂库存增加
    两张流水均带 source/purpose = 厂间调拨, 便于追溯和对账。
    """
    __tablename__ = "transfer"
    id = db.Column(db.Integer, primary_key=True)
    no = db.Column(db.String(64), unique=True, nullable=False, index=True)    # 调拨单号, 如 TR20260928xxx
    from_factory_id = db.Column(db.Integer, db.ForeignKey("factory.id"), nullable=False, index=True)
    to_factory_id = db.Column(db.Integer, db.ForeignKey("factory.id"), nullable=False, index=True)
    material_id = db.Column(db.Integer, db.ForeignKey("material.id"), nullable=False, index=True)
    qty = db.Column(db.Float, nullable=False)                                # 调拨数量(正)
    operator = db.Column(db.String(64), default="")
    occur_date = db.Column(db.Date, default=date.today)
    remark = db.Column(db.String(255), default="")
    created_at = db.Column(db.DateTime, default=datetime.now)