"""按业务键同步系统关联，保留关联 ID，并复用已停用关联。"""
from datetime import datetime

from app.core.utils import generate_uuid


def sync_relations(db, model, tenant_no, owner, key_fields, desired_keys, actor, unique_history=False):
    desired = list(dict.fromkeys(desired_keys))
    rows = db.query(model).filter(
        model.tenant_no == tenant_no,
        *(getattr(model, field) == value for field, value in owner.items()),
    ).with_for_update().all()
    grouped = {}
    for row in rows:
        grouped.setdefault(tuple(getattr(row, f) for f in key_fields), []).append(row)
    desired_set = set(desired)
    # 历史重复关系需专项修复；不能为规避唯一键而物理删除或静默替换原记录。
    for key, matches in grouped.items():
        active = [r for r in matches if r.del_flag == 0]
        if len(active) > 1 or (unique_history and active and key not in desired_set and len(matches) > 1):
            raise ValueError("存在重复的历史关联，请先核查后再调整该关联")
    now = datetime.now()
    for key, matches in grouped.items():
        if key not in desired_set:
            for row in matches:
                if row.del_flag == 0:
                    row.del_flag = 1
                    row.update_by = actor
                    row.update_time = now
    for key in desired:
        matches = grouped.get(key, [])
        active = next((r for r in matches if r.del_flag == 0), None)
        if active is not None:
            continue
        if matches:
            row = sorted(matches, key=lambda r: r.id)[0]
            row.del_flag = 0
            row.update_by = actor
            row.update_time = now
        else:
            db.add(model(
                id=generate_uuid(), tenant_no=tenant_no, **owner,
                **dict(zip(key_fields, key)), order_num=0,
                create_by=actor, create_dept_id='', create_time=now,
                update_by=actor, update_time=now, del_flag=0,
            ))


def assert_relation_targets(db, model, tenant_no, ids, label):
    targets = {value for value in ids or [] if value}
    if not targets:
        return
    found = {row.id for row in db.query(model).filter(
        model.id.in_(targets), model.tenant_no == tenant_no, model.del_flag == 0,
    ).all()}
    if targets != found:
        raise ValueError(f'{label}不存在、已删除或不属于当前租户')