"""业务数据仓储：业务单、明细、状态留痕与归属留痕。

只读写数据并 flush；commit/rollback 与业务异常一律在 service 层。
归属留痕复用 ownership_change_logs（owner_type=2 为业务维度，常量在
models/customer.py 定义）。
"""

from sqlalchemy import Row, Select, delete, exists, func, or_, select, update
from sqlalchemy.orm import Session, aliased

from app.models import (
    Business,
    BusinessItem,
    BusinessStatusLog,
    Customer,
    OwnershipChangeLog,
    Personnel,
    Receipt,
    SecondaryAllocation,
    Shipment,
)
from app.models.customer import OWNER_TYPE_BUSINESS
from app.repositories import ownership_log_repository
from app.repositories.ownership_log_repository import OwnershipLogRef
from app.schemas.business import BusinessQuery


def get_by_id(session: Session, business_id: int, *, for_update: bool = False) -> Business | None:
    """按主键取业务行；for_update 供删除保护、编辑门槛与状态机使用。"""
    stmt = select(Business).where(Business.id == business_id)
    if for_update:
        stmt = stmt.with_for_update()
    return session.execute(stmt).scalars().first()


def has_docs(session: Session, business_id: int) -> bool:
    """业务名下是否已有发货单或回款（换客户/删除保护的引用检查）。

    单条 OR exists 一次往返；新增挂靠业务的单据类型时在此补充条件，
    编辑与删除两处共用同一判定，防「delete 补了检查、update 漏补」的分叉。
    """
    stmt = select(
        or_(
            exists().where(Shipment.business_id == business_id),
            exists().where(Receipt.business_id == business_id),
        )
    )
    return bool(session.execute(stmt).scalar())


def create(session: Session, business: Business) -> None:
    """新增业务行（不 commit，flush 让自增 id 就位）。"""
    session.add(business)
    session.flush()


def get_with_names(
    session: Session, business_id: int, *, for_update: bool = False
) -> tuple[Business, str, str | None, str | None] | None:
    """业务行 + 客户名 + 负责人名 + 协助人名（DTO 与审计摘要共用）。

    for_update 供编辑/状态流转/归属变更使用：与发货/回款写路径的
    get_by_id(for_update=True) 同一锁口径，编辑事务与单据写事务互斥，
    「有发货禁换客户」的快照读校验不再被并发新增旁路。
    """
    owner = aliased(Personnel)
    assistant = aliased(Personnel)
    stmt = (
        select(Business, Customer.company_name, owner.personnel_name, assistant.personnel_name)
        .join(Customer, Customer.id == Business.customer_id)
        .outerjoin(owner, owner.id == Business.owner_personnel_id)
        .outerjoin(assistant, assistant.id == Business.assistant_personnel_id)
        .where(Business.id == business_id)
    )
    if for_update:
        stmt = stmt.with_for_update()
    return session.execute(stmt).first()


def _apply_filters(stmt: Select, query: BusinessQuery) -> Select:
    """业务列表的筛选条件（调用方须已 join Customer）。"""
    if query.keyword:
        # 业务编号/公司名称双列 OR 模糊；contains(autoescape) 同 query_utils.fuzzy
        # 的转义口径（fuzzy 为单列 where 语义，双列 OR 在此直接组合）
        stmt = stmt.where(
            or_(
                Business.business_no.contains(query.keyword, autoescape=True),
                Customer.company_name.contains(query.keyword, autoescape=True),
            )
        )
    if query.status is not None:
        stmt = stmt.where(Business.status == query.status)
    if query.customer_id is not None:
        stmt = stmt.where(Business.customer_id == query.customer_id)
    if query.owner_personnel_id is not None:
        stmt = stmt.where(Business.owner_personnel_id == query.owner_personnel_id)
    if query.date_from is not None:
        stmt = stmt.where(Business.business_date >= query.date_from)
    if query.date_to is not None:
        stmt = stmt.where(Business.business_date <= query.date_to)
    return stmt


def list_businesses(
    session: Session, query: BusinessQuery
) -> list[tuple[Business, str, str | None, str | None]]:
    """分页查询业务（附客户名/负责人名/协助人名），按 id 倒序。"""
    owner = aliased(Personnel)
    assistant = aliased(Personnel)
    stmt = select(
        Business, Customer.company_name, owner.personnel_name, assistant.personnel_name
    ).join(Customer, Customer.id == Business.customer_id)
    stmt = _apply_filters(stmt, query)
    stmt = (
        stmt.outerjoin(owner, owner.id == Business.owner_personnel_id)
        .outerjoin(assistant, assistant.id == Business.assistant_personnel_id)
        .order_by(Business.id.desc())
        .offset(query.offset)
        .limit(query.page_size)
    )
    return list(session.execute(stmt).all())


def count_businesses(session: Session, query: BusinessQuery) -> int:
    stmt = (
        select(func.count())
        .select_from(Business)
        .join(Customer, Customer.id == Business.customer_id)
    )
    stmt = _apply_filters(stmt, query)
    return int(session.execute(stmt).scalar_one())


def list_items(session: Session, business_id: int) -> list[BusinessItem]:
    """业务明细行（编辑回显与汇总重算共用）。"""
    return list(
        session.execute(
            select(BusinessItem)
            .where(BusinessItem.business_id == business_id)
            .order_by(BusinessItem.id)
        ).scalars()
    )


def replace_items(session: Session, business_id: int, rows: list[BusinessItem]) -> None:
    """全量替换明细：先删、立即 flush、再插入（replace_roles 先例的防御写法）。

    同一 flush 中 SQLAlchemy 先处理 INSERT 后处理 DELETE，先删后插不落库
    会在有唯一键的表上撞键；business_items 虽无唯一键，统一按此写法防御。
    """
    session.execute(delete(BusinessItem).where(BusinessItem.business_id == business_id))
    session.flush()
    for row in rows:
        row.business_id = business_id
        session.add(row)
    session.flush()


def list_allocations(
    session: Session, business_id: int, *, active_only: bool = True
) -> list[SecondaryAllocation]:
    """二次分配方案（详情回显与核算取数；默认仅当前生效版本）。"""
    stmt = select(SecondaryAllocation).where(SecondaryAllocation.business_id == business_id)
    if active_only:
        stmt = stmt.where(SecondaryAllocation.is_active == 1)
    return list(
        session.execute(
            stmt.order_by(SecondaryAllocation.version_no, SecondaryAllocation.id)
        ).scalars()
    )


def list_allocation_versions(session: Session, business_id: int) -> list[SecondaryAllocation]:
    """方案全部版本行（含历史；业务详情「方案历史」用，按版本正序）。"""
    return list_allocations(session, business_id, active_only=False)


def replace_allocations(
    session: Session, business_id: int, rows: list[SecondaryAllocation]
) -> None:
    """全量替换二次分配方案：旧生效行置历史，新行按下一版本号插入。

    不 commit（事务边界在服务层）。版本行 append-only——编辑与清空都不
    物理删除，驳回后仍可回溯被否决方案的参与人与比例。空 ``rows`` 表示
    只清空生效态（不产生新版本）。
    """
    deactivate_allocations(session, business_id)
    if not rows:
        return
    next_version = (
        session.execute(
            select(func.coalesce(func.max(SecondaryAllocation.version_no), 0)).where(
                SecondaryAllocation.business_id == business_id
            )
        ).scalar_one()
        + 1
    )
    for row in rows:
        row.business_id = business_id
        row.version_no = next_version
        row.is_active = 1
        session.add(row)
    session.flush()


def deactivate_allocations(session: Session, business_id: int) -> None:
    """把业务的当前生效方案置为历史（审批驳回/编辑替换时调用；行保留）。

    被否决的方案不得以「当前生效行」身份继续被核算取到；``is_active=0``
    后核算侧自然读不到，而历史版本仍可在业务详情回溯。不 commit。

    显式声明 ``synchronize_session="fetch"``：Core UPDATE 默认走 auto 策略
    （优先 evaluate，本例的条件恰好能在 Python 侧求值，故实测也会刷新在途
    对象）。显式写 fetch 是为了不把「在途对象被刷新」这件事押在 evaluate
    能否解析条件上——条件一旦复杂化，auto 会退化为不刷新，同一会话里已
    加载的方案行就会停留在 ``is_active=1`` 的过期内存值（查询虽有
    is_active 过滤，但行对象本身仍是「生效态」，被序列化或参与判断就是
    错的）。
    """
    session.execute(
        update(SecondaryAllocation)
        .where(
            SecondaryAllocation.business_id == business_id,
            SecondaryAllocation.is_active == 1,
        )
        .values(is_active=0)
        .execution_options(synchronize_session="fetch")
    )
    session.flush()


def add_status_log(session: Session, log: BusinessStatusLog) -> None:
    """追加状态留痕（不 commit）。"""
    session.add(log)
    session.flush()


def list_status_logs(
    session: Session, business_id: int, *, offset: int, limit: int
) -> list[BusinessStatusLog]:
    """状态流转时间线（详情页），按时间正序（时间线从创建起展示）。"""
    return list(
        session.execute(
            select(BusinessStatusLog)
            .where(BusinessStatusLog.business_id == business_id)
            .order_by(BusinessStatusLog.create_time, BusinessStatusLog.id)
            .offset(offset)
            .limit(limit)
        ).scalars()
    )


def count_status_logs(session: Session, business_id: int) -> int:
    return int(
        session.execute(
            select(func.count())
            .select_from(BusinessStatusLog)
            .where(BusinessStatusLog.business_id == business_id)
        ).scalar_one()
    )


def add_ownership_log(session: Session, log: OwnershipChangeLog) -> None:
    """追加归属变更留痕（共享实现，不 commit）。"""
    ownership_log_repository.add(session, log)


def list_ownership_logs(
    session: Session, business_id: int, *, offset: int, limit: int
) -> list[Row]:
    """某业务的归属变更留痕（共享实现，owner_type/business_id 参数化）。"""
    return ownership_log_repository.list_by_ref(
        session, _business_log_ref(business_id), offset=offset, limit=limit
    )


def count_ownership_logs(session: Session, business_id: int) -> int:
    return ownership_log_repository.count_by_ref(session, _business_log_ref(business_id))


def _business_log_ref(business_id: int) -> OwnershipLogRef:
    """业务维度的归属留痕锚点。"""
    return OwnershipLogRef(
        owner_type=OWNER_TYPE_BUSINESS,
        ref_column=OwnershipChangeLog.business_id,
        ref_id=business_id,
    )