from iti_system.models import SysDept
from iti_system.routes.schemas.dept import SysDeptQuery
from iti.applications.extensions import db
from iti.applications.common.utils import build_tree_from_list
from sqlalchemy.orm import joinedload, noload
from sqlalchemy.sql._typing import ColumnExpressionArgument


def get_dept_tree_or_page(query_data: SysDeptQuery, with_leader: bool = False):
    """
    获取部门树
    """
    # 若根据 Leader 查询，查询该 Leader 的部门列表（分页），而非树
    if query_data.leader_id:
        return (
            SysDept.query.filter(SysDept.leader_id == query_data.leader_id)
            .order_by(SysDept.sort)
            .paginate(page=query_data.page, per_page=query_data.size)
        )

    # 若根据 Parent 查询，查询该 Parent 的子部门树，否则查询所有部门树
    cte_query = build_descendants_cte(SysDept.parent_id == query_data.parent_id)

    if query_data.name:
        cte_query = cte_query.filter(SysDept.name.like(f"%{query_data.name}%"))
    if query_data.status:
        cte_query = cte_query.filter(SysDept.status == query_data.status)
    if query_data.startTime:
        cte_query = cte_query.filter(SysDept.created_at >= query_data.startTime)
    if query_data.endTime:
        cte_query = cte_query.filter(SysDept.created_at <= query_data.endTime)
    cte_query = cte_query.order_by(SysDept.parent_id, SysDept.sort).options(
        noload(SysDept.parent), noload(SysDept.children)
    )
    if with_leader:
        cte_query = cte_query.options(joinedload(SysDept.leader))
    return build_tree_from_list(cte_query.all())


def build_descendants_cte(*criterion: ColumnExpressionArgument[bool]):
    """
    构建获取后代的递归CTE
    """
    hierarchy = (
        db.session.query(SysDept.id, SysDept.parent_id)
        .filter(*criterion)
        .cte("hierarchy", recursive=True)
    )
    bt = db.session.query(SysDept.id, SysDept.parent_id).join(
        hierarchy, hierarchy.c.id == SysDept.parent_id
    )
    q = hierarchy.union_all(bt)
    return db.session.query(SysDept).join(q, SysDept.id == q.c.id)


def build_ancestors_cte(*criterion: ColumnExpressionArgument[bool]):
    """
    构建获取祖先的递归CTE
    """
    hierarchy = (
        db.session.query(SysDept.id, SysDept.parent_id)
        .filter(*criterion)
        .cte("hierarchy", recursive=True)
    )
    bt = db.session.query(SysDept.id, SysDept.parent_id).join(
        hierarchy, hierarchy.c.id == SysDept.parent_id
    )
    q = hierarchy.union_all(bt)
    return db.session.query(SysDept).join(q, SysDept.id == q.c.id)