"""业务工单链：认领 → 提交审核 → 复核（软校验职责分离，流转写审计）。

状态机：待处理 ─认领─► 处理中 ─提交审核─► 待审核 ─复核─► 已完成 / 已驳回（终态）。
流转均用条件更新防并发跳步，每次流转写 audit_log。
"""
from __future__ import annotations

from datetime import datetime

from sqlalchemy.ext.asyncio import AsyncSession

from model.audit_log import AuditLog
from model.biz_work_order import BizWorkOrder
from model.sys_user import SysUser
from repositories.biz_work_order import BizWorkOrderRepo
from schemas.work_order import WorkOrderResp
from utils.exceptions import NotFoundError, ParamError
from utils.pagination import normalize_pagination, pagination_result


def _audit(db: AsyncSession, user: SysUser, module: str, action: str, target, detail: str) -> None:
    db.add(
        AuditLog(
            user_id=user.id,
            username=user.real_name or user.username,
            module=module,
            action=action,
            target=str(target),
            detail=detail,
            status="成功",
        )
    )


def _resp(wo: BizWorkOrder) -> WorkOrderResp:
    return WorkOrderResp(
        id=wo.id,
        work_order_no=wo.work_order_no,
        order_type=wo.order_type,
        sub_type=wo.sub_type,
        customer_id=wo.customer_id,
        submitter_id=wo.submitter_id,
        handler_id=wo.handler_id,
        current_node=wo.current_node,
        priority=wo.priority,
        status=wo.status,
        biz_content=wo.biz_content,
        create_time=wo.create_time,
        update_time=wo.update_time,
    )


async def list_work_orders(
    db: AsyncSession,
    status: str | None = None,
    *,
    page: int = 1,
    page_size: int = 10,
) -> dict:
    """分页查询公共工单，默认每页 10 条。"""
    page, page_size, offset = normalize_pagination(page, page_size)
    repo = BizWorkOrderRepo(db)
    orders = await repo.list_with_filter(
        status=status,
        limit=page_size,
        offset=offset,
    )
    return pagination_result(
        [_resp(o).model_dump(mode="json") for o in orders],
        await repo.count_with_filter(status=status),
        page=page,
        page_size=page_size,
    )


async def get_work_order(db: AsyncSession, work_order_id: int) -> WorkOrderResp:
    wo = await BizWorkOrderRepo(db).get(work_order_id)
    if wo is None:
        raise NotFoundError("工单不存在")
    return _resp(wo)


async def claim(db: AsyncSession, user: SysUser, work_order_id: int) -> dict:
    """认领：待处理 → 处理中，handler_id 记为当前专员。"""
    wo_repo = BizWorkOrderRepo(db)
    wo = await wo_repo.get(work_order_id)
    if wo is None:
        raise NotFoundError("工单不存在")
    try:
        if not await wo_repo.conditional_transition(
            work_order_id,
            from_status="待处理",
            to_status="处理中",
            handler_id=user.id,
            update_time=datetime.now(),
        ):
            raise ParamError("工单已被认领或状态已变更")
        _audit(db, user, "work_order", "claim", work_order_id, f"认领工单 {wo.work_order_no}：待处理 → 处理中")
        await db.commit()
        return {"work_order_id": work_order_id, "status": "处理中", "work_order_no": wo.work_order_no}
    except Exception:
        await db.rollback()
        raise


async def submit_review(db: AsyncSession, user: SysUser, work_order_id: int) -> dict:
    """提交审核：处理中 → 待审核。"""
    wo_repo = BizWorkOrderRepo(db)
    wo = await wo_repo.get(work_order_id)
    if wo is None:
        raise NotFoundError("工单不存在")
    try:
        if not await wo_repo.conditional_transition(
            work_order_id,
            from_status="处理中",
            to_status="待审核",
            current_node="复核",
            update_time=datetime.now(),
        ):
            raise ParamError("工单状态已变更，无法提交审核")
        _audit(db, user, "work_order", "submit_review", work_order_id, f"提交审核工单 {wo.work_order_no}：处理中 → 待审核")
        await db.commit()
        return {"work_order_id": work_order_id, "status": "待审核", "work_order_no": wo.work_order_no}
    except Exception:
        await db.rollback()
        raise


async def review(
    db: AsyncSession, user: SysUser, work_order_id: int, approve: bool, comment: str | None = None
) -> dict:
    """复核：待审核 → 已完成 / 已驳回（终态）。复核人与处理人为同一人时软校验仅提示。"""
    wo_repo = BizWorkOrderRepo(db)
    wo = await wo_repo.get(work_order_id)
    if wo is None:
        raise NotFoundError("工单不存在")
    to_status = "已完成" if approve else "已驳回"
    warning = "复核人与处理人为同一人" if wo.handler_id == user.id else None
    try:
        if not await wo_repo.conditional_transition(
            work_order_id,
            from_status="待审核",
            to_status=to_status,
            current_node="完成",
            update_time=datetime.now(),
        ):
            raise ParamError("工单状态已变更，无法复核")
        detail = f"复核工单 {wo.work_order_no}：待审核 → {to_status}"
        if comment:
            detail += f"（{comment}）"
        _audit(db, user, "work_order", "review", work_order_id, detail)
        await db.commit()
        return {
            "work_order_id": work_order_id,
            "status": to_status,
            "work_order_no": wo.work_order_no,
            "warning": warning,
        }
    except Exception:
        await db.rollback()
        raise