dingdanquanliucheng/backend/app/services/product_service.py

"""产品管理服务层。

负责产品分类和产品主档（含规格明细）的增删改查业务逻辑。
依赖 ProductRepository 进行数据持久化，依赖 audit_service 记录操作审计日志。
产品采用"产品名称 + 规格"的二级结构，同一产品名称下可有多条规格记录。
"""

from sqlalchemy.exc import SQLAlchemyError
from sqlalchemy.orm import Session

from backend.app.core.error_codes import ErrorCode
from backend.app.core.exceptions import AppException
from backend.app.repositories.product_repository import ProductRepository
from backend.app.services.audit_service import audit_service


class ProductService:
    """产品服务，封装产品分类和产品规格的 CRUD 业务逻辑。

    依赖:
        ProductRepository - 产品数据访问
        audit_service - 操作审计日志
    """

    def __init__(self) -> None:
        self.repository = ProductRepository()

    def list_categories(self, session: Session | None = None, filters: dict | None = None) -> dict:
        """查询产品分类列表。

        Args:
            session: 数据库会话
            filters: 查询过滤条件

        Returns:
            包含 total、page_no、page_size、list 的分页字典

        被调用路由: products.py - GET /products/categories
        """
        if session is None:
            raise AppException(code=ErrorCode.PARAM_ERROR, message="数据库会话未初始化", status_code=500)
        try:
            categories = self.repository.list_categories(session, filters or {})
            return {
                "total": len(categories),
                "page_no": 1,
                "page_size": len(categories) or 20,
                "list": [
                    {
                        "category_id": category.id,
                        "category_name": category.category_name,
                        "category_code": category.category_code,
                        "sort_no": category.sort_no,
                        "status": category.status,
                        "remark": category.remark,
                    }
                    for category in categories
                ],
            }
        except SQLAlchemyError as exc:
            raise AppException(code=ErrorCode.SYSTEM_ERROR, message="数据库操作失败", status_code=500) from exc

    def create_category(self, payload: dict, session: Session | None = None) -> dict:
        """创建产品分类。

        校验分类名称和编码非空，并检查编码唯一性。自动记录审计日志。

        Args:
            payload: 包含 category_name、category_code 的请求体
            session: 数据库会话

        Returns:
            包含 category_id、category_name、category_code、status 的结果字典

        被调用路由: products.py - POST /products/categories
        """
        if session is None:
            raise AppException(code=ErrorCode.PARAM_ERROR, message="数据库会话未初始化", status_code=500)
        try:
            if not payload["category_name"].strip():
                raise AppException(code=ErrorCode.PARAM_ERROR, message="分类名称不能为空", status_code=400)
            if not payload["category_code"].strip():
                raise AppException(code=ErrorCode.PARAM_ERROR, message="分类编码不能为空", status_code=400)
            existed = self.repository.get_category_by_code(session, payload["category_code"])
            if existed is not None:
                raise AppException(code=ErrorCode.DUPLICATE, message="分类编码已存在", status_code=400)
            category = self.repository.create_category(session, payload)
            audit_service.write_log(
                session,
                {
                    "operate_type": "product_category_create",
                    "biz_type": "product_category",
                    "biz_id": category.id,
                    "before_value": None,
                    "after_value": {"category_name": category.category_name, "category_code": category.category_code},
                    "remark": f"新增产品分类 {category.category_name}",
                },
            )
            session.commit()
            return {
                "category_id": category.id,
                "category_name": category.category_name,
                "category_code": category.category_code,
                "status": category.status,
            }
        except AppException:
            session.rollback()
            raise
        except SQLAlchemyError as exc:
            session.rollback()
            raise AppException(code=ErrorCode.SYSTEM_ERROR, message="数据库操作失败", status_code=500) from exc

    def update_category(self, category_id: int, payload: dict, session: Session | None = None) -> dict:
        """更新产品分类。

        校验分类编码唯一性（排除自身）。

        Args:
            category_id: 分类 ID
            payload: 包含更新字段的请求体
            session: 数据库会话

        Returns:
            更新结果字典

        被调用路由: products.py - PUT /products/categories/{category_id}
        """
        if session is None:
            raise AppException(code=ErrorCode.PARAM_ERROR, message="数据库会话未初始化", status_code=500)
        try:
            if not payload["category_name"].strip():
                raise AppException(code=ErrorCode.PARAM_ERROR, message="分类名称不能为空", status_code=400)
            if not payload["category_code"].strip():
                raise AppException(code=ErrorCode.PARAM_ERROR, message="分类编码不能为空", status_code=400)
            category = self.repository.get_category(session, category_id)
            if category is None:
                raise AppException(code=ErrorCode.NOT_FOUND, message="产品分类不存在", status_code=404)
            existed = self.repository.get_category_by_code(session, payload["category_code"])
            if existed is not None and existed.id != category_id:
                raise AppException(code=ErrorCode.DUPLICATE, message="分类编码已存在", status_code=400)
            self.repository.update_category(session, category, payload)
            session.commit()
            return {"category_id": category_id, "updated": True}
        except AppException:
            session.rollback()
            raise
        except SQLAlchemyError as exc:
            session.rollback()
            raise AppException(code=ErrorCode.SYSTEM_ERROR, message="数据库操作失败", status_code=500) from exc

    def _group_products(self, products: list, categories: dict[int, object]) -> list[dict]:
        """将产品规格列表按产品名称分组。

        同一产品名称下的多条规格记录合并为一条，规格列表放在 specifications 字段中。
        自动将第一条规格标记为默认（若无显式默认）。

        Args:
            products: 产品 ORM 对象列表
            categories: 分类 ID 到分类 ORM 对象的映射

        Returns:
            按产品名称分组后的产品列表
        """
        grouped: dict[str, dict] = {}
        for product in products:
            key = product.product_name
            category_name = categories[product.category_id].category_name if product.category_id in categories else (product.category or "")
            entry = grouped.setdefault(
                key,
                {
                    "product_name": product.product_name,
                    "product_id": product.id,
                    "category_id": product.category_id,
                    "category_name": category_name,
                    "status": product.status,
                    "remark": product.remark,
                    "specifications": [],
                },
            )
            entry["specifications"].append(
                {
                    "product_id": product.id,
                    "specification": product.specification,
                    "unit": product.unit,
                    "cost_price": float(product.cost_price or 0),
                    "sale_price": float(product.sale_price or 0),
                    "status": product.status,
                    "remark": product.remark,
                    "is_default": bool(getattr(product, "is_default", 0)),
                }
            )
        for entry in grouped.values():
            if entry["specifications"] and not any(spec["is_default"] for spec in entry["specifications"]):
                entry["specifications"][0]["is_default"] = True
        return list(grouped.values())

    def list_products(self, filters: dict | None = None, session: Session | None = None) -> dict:
        """查询产品列表（按名称分组）。

        先查询所有产品规格，再按产品名称分组聚合。

        Args:
            filters: 查询过滤条件
            session: 数据库会话

        Returns:
            包含 total、page_no、page_size、list 的分页字典

        被调用路由: products.py - GET /products
        """
        if session is None:
            raise AppException(code=ErrorCode.PARAM_ERROR, message="数据库会话未初始化", status_code=500)
        try:
            products = self.repository.list_products(session, filters or {})
            categories = {category.id: category for category in self.repository.list_categories(session, {})}
            grouped_list = self._group_products(products, categories)
            return {
                "total": len(grouped_list),
                "page_no": 1,
                "page_size": len(grouped_list) or 20,
                "list": grouped_list,
            }
        except SQLAlchemyError as exc:
            raise AppException(code=ErrorCode.SYSTEM_ERROR, message="数据库操作失败", status_code=500) from exc

    def update_product(self, product_id: int, payload: dict, session: Session | None = None) -> dict:
        """更新产品主档信息（名称、分类、状态等）。

        仅更新产品级别的公共字段，不影响规格明细。

        Args:
            product_id: 产品 ID
            payload: 包含更新字段的请求体
            session: 数据库会话

        Returns:
            更新结果字典

        被调用路由: products.py - PUT /products/{product_id}
        """
        if session is None:
            raise AppException(code=ErrorCode.PARAM_ERROR, message="数据库会话未初始化", status_code=500)
        try:
            product = self.repository.get_product(session, product_id)
            if product is None:
                raise AppException(code=ErrorCode.NOT_FOUND, message="产品主档不存在", status_code=404)
            if not payload["product_name"].strip():
                raise AppException(code=ErrorCode.PARAM_ERROR, message="产品名称不能为空", status_code=400)
            category = None
            if payload.get("category_id") is not None:
                category = self.repository.get_category(session, payload["category_id"])
                if category is None or category.status != 1:
                    raise AppException(code=ErrorCode.NOT_FOUND, message="产品分类不存在或已停用", status_code=404)
            product.product_name = payload["product_name"]
            product.category_id = payload.get("category_id")
            product.category = category.category_name if category else None
            product.status = payload.get("status", product.status)
            product.remark = payload.get("remark", product.remark)
            session.add(product)
            session.commit()
            return {"product_id": product.id, "product_name": product.product_name, "updated": True}
        except AppException:
            session.rollback()
            raise
        except SQLAlchemyError as exc:
            session.rollback()
            raise AppException(code=ErrorCode.SYSTEM_ERROR, message="数据库操作失败", status_code=500) from exc

    def update_product_specification(self, product_id: int, payload: dict, session: Session | None = None) -> dict:
        """更新产品规格明细。

        校验规格在同一产品下唯一，可修改规格名称、单位、价格等。

        Args:
            product_id: 产品（规格） ID
            payload: 包含 specification、unit、cost_price、sale_price 等的请求体
            session: 数据库会话

        Returns:
            更新结果字典

        被调用路由: products.py - PUT /products/{product_id}/specification
        """
        if session is None:
            raise AppException(code=ErrorCode.PARAM_ERROR, message="数据库会话未初始化", status_code=500)
        try:
            product = self.repository.get_product(session, product_id)
            if product is None:
                raise AppException(code=ErrorCode.NOT_FOUND, message="产品规格不存在", status_code=404)
            if not payload["specification"].strip():
                raise AppException(code=ErrorCode.PARAM_ERROR, message="产品规格不能为空", status_code=400)
            if not payload["unit"].strip():
                raise AppException(code=ErrorCode.PARAM_ERROR, message="产品单位不能为空", status_code=400)
            existed = self.repository.get_product_by_name_and_specification(session, product.product_name, payload["specification"])
            if existed is not None and existed.id != product_id:
                raise AppException(code=ErrorCode.DUPLICATE, message="同一产品下的规格不能重复", status_code=400)
            category = None
            if payload.get("category_id") is not None:
                category = self.repository.get_category(session, payload["category_id"])
                if category is None or category.status != 1:
                    raise AppException(code=ErrorCode.NOT_FOUND, message="产品分类不存在或已停用", status_code=404)
            product.specification = payload["specification"]
            product.unit = payload["unit"]
            product.category_id = payload.get("category_id")
            product.category = category.category_name if category else product.category
            product.cost_price = payload.get("cost_price", product.cost_price)
            product.sale_price = payload.get("sale_price", product.sale_price)
            product.status = payload.get("status", product.status)
            product.remark = payload.get("remark", product.remark)
            session.add(product)
            session.commit()
            return {"product_id": product.id, "product_name": product.product_name, "updated": True}
        except AppException:
            session.rollback()
            raise
        except SQLAlchemyError as exc:
            session.rollback()
            raise AppException(code=ErrorCode.SYSTEM_ERROR, message="数据库操作失败", status_code=500) from exc

    def set_default_specification(self, product_id: int, session: Session | None = None) -> dict:
        """设置产品默认规格。

        将指定规格标记为默认，同名产品下的其他规格清除默认标记。

        Args:
            product_id: 产品（规格） ID
            session: 数据库会话

        Returns:
            设置结果字典

        被调用路由: products.py - POST /products/{product_id}/set-default
        """
        if session is None:
            raise AppException(code=ErrorCode.PARAM_ERROR, message="数据库会话未初始化", status_code=500)
        try:
            product = self.repository.get_product(session, product_id)
            if product is None:
                raise AppException(code=ErrorCode.NOT_FOUND, message="产品规格不存在", status_code=404)
            siblings = self.repository.list_products(session, {"product_name": product.product_name})
            for sibling in siblings:
                sibling.is_default = 1 if sibling.id == product.id else 0
                session.add(sibling)
            session.flush()
            session.commit()
            return {"product_id": product.id, "product_name": product.product_name, "is_default": True}
        except AppException:
            session.rollback()
            raise
        except SQLAlchemyError as exc:
            session.rollback()
            raise AppException(code=ErrorCode.SYSTEM_ERROR, message="数据库操作失败", status_code=500) from exc

    def create_product(self, payload: dict, session: Session | None = None) -> dict:
        """创建新产品（含规格明细）。

        产品名称为公共字段，每条规格明细单独创建一条数据库记录。
        同一产品下的规格名称不可重复。自动记录审计日志。

        Args:
            payload: 包含 product_name、category_id、specifications 列表的请求体
            session: 数据库会话

        Returns:
            创建结果字典，包含产品名称和所有规格明细

        被调用路由: products.py - POST /products
        """
        if session is None:
            raise AppException(code=ErrorCode.PARAM_ERROR, message="数据库会话未初始化", status_code=500)
        try:
            if not payload["product_name"].strip():
                raise AppException(code=ErrorCode.PARAM_ERROR, message="产品名称不能为空", status_code=400)
            specifications = payload.get("specifications") or []
            if not specifications:
                raise AppException(code=ErrorCode.PARAM_ERROR, message="请至少填写一个规格明细", status_code=400)

            category = None
            if payload.get("category_id") is not None:
                category = self.repository.get_category(session, payload["category_id"])
                if category is None or category.status != 1:
                    raise AppException(code=ErrorCode.NOT_FOUND, message="产品分类不存在或已停用", status_code=404)

            created_specs = []
            for spec in specifications:
                if not spec["specification"].strip():
                    raise AppException(code=ErrorCode.PARAM_ERROR, message="产品规格不能为空", status_code=400)
                if not spec["unit"].strip():
                    raise AppException(code=ErrorCode.PARAM_ERROR, message="产品单位不能为空", status_code=400)
                existed = self.repository.get_product_by_name_and_specification(
                    session,
                    payload["product_name"],
                    spec["specification"],
                )
                if existed is not None:
                    raise AppException(code=ErrorCode.DUPLICATE, message="同一产品下的规格不能重复", status_code=400)
                product = self.repository.create_product(
                    session,
                    {
                        "product_name": payload["product_name"],
                        "specification": spec["specification"],
                        "unit": spec["unit"],
                        "category_id": spec.get("category_id") or payload.get("category_id"),
                        "category": category.category_name if category else None,
                        "cost_price": spec.get("cost_price", 0),
                        "sale_price": spec.get("sale_price", 0),
                        "status": spec.get("status", payload.get("status", 1)),
                        "remark": spec.get("remark") or payload.get("remark"),
                    },
                )
                created_specs.append(product)
            audit_service.write_log(
                session,
                {
                    "operate_type": "product_create",
                    "biz_type": "product",
                    "biz_id": created_specs[0].id if created_specs else 0,
                    "before_value": None,
                    "after_value": {
                        "product_name": payload["product_name"],
                        "spec_count": len(created_specs),
                        "category_id": payload.get("category_id"),
                    },
                    "remark": f"新增产品 {payload['product_name']}，共 {len(created_specs)} 个规格",
                },
            )
            session.commit()
            return {
                "product_name": payload["product_name"],
                "product_id": created_specs[0].id if created_specs else None,
                "specifications": [
                    {
                        "product_id": item.id,
                        "specification": item.specification,
                        "unit": item.unit,
                        "cost_price": float(item.cost_price or 0),
                        "sale_price": float(item.sale_price or 0),
                        "status": item.status,
                        "remark": item.remark,
                        "is_default": index == 0,
                    }
                    for index, item in enumerate(created_specs)
                ],
            }
        except AppException:
            session.rollback()
            raise
        except SQLAlchemyError as exc:
            session.rollback()
            raise AppException(code=ErrorCode.SYSTEM_ERROR, message="数据库操作失败", status_code=500) from exc

    def get_product(self, product_id: int, session: Session | None = None) -> dict:
        """查询单个产品详情（含所有规格明细）。

        通过产品名称查询同名所有规格，再按分组逻辑返回完整产品信息。

        Args:
            product_id: 产品（规格） ID
            session: 数据库会话

        Returns:
            产品详情字典（含 specifications 列表）

        被调用路由: products.py - GET /products/{product_id}
        """
        if session is None:
            raise AppException(code=ErrorCode.PARAM_ERROR, message="数据库会话未初始化", status_code=500)
        try:
            product = self.repository.get_product(session, product_id)
            if product is None:
                raise AppException(code=ErrorCode.NOT_FOUND, message="产品不存在", status_code=404)
            products = self.repository.list_products(session, {"product_name": product.product_name})
            categories = {category.id: category for category in self.repository.list_categories(session, {})}
            grouped = self._group_products(products, categories)
            if grouped:
                return grouped[0]
            raise AppException(code=ErrorCode.NOT_FOUND, message="产品不存在", status_code=404)
        except AppException:
            raise
        except SQLAlchemyError as exc:
            raise AppException(code=ErrorCode.SYSTEM_ERROR, message="数据库操作失败", status_code=500) from exc


product_service = ProductService()