import re
from datetime import datetime, timezone
from uuid import uuid4

from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.orm import Session

from app.database import get_db
from app.models import NetObjectModel
from app.schemas import EntityResponse, ListResponse, NetObject, NetObjectCreate, NetObjectUpdate
from app.services.inventory import _to_net_object

router = APIRouter(prefix='/objects', tags=['objects'])


def _slugify(name: str) -> str:
    slug = name.lower().strip()
    slug = re.sub(r'[^\w\s-]', '', slug)
    slug = re.sub(r'[\s_-]+', '-', slug)
    return slug.strip('-')


@router.get('', response_model=ListResponse[NetObject])
def list_objects(db: Session = Depends(get_db)):
    rows = db.query(NetObjectModel).all()
    return ListResponse(count=len(rows), items=[_to_net_object(r) for r in rows])


@router.get('/{object_id}', response_model=EntityResponse[NetObject])
def get_object(object_id: str, db: Session = Depends(get_db)):
    row = db.query(NetObjectModel).filter(NetObjectModel.id == object_id).first()
    if not row:
        raise HTTPException(status_code=404, detail='Object not found')
    return EntityResponse(item=_to_net_object(row))


@router.post('', response_model=EntityResponse[NetObject], status_code=201)
def create_object(body: NetObjectCreate, db: Session = Depends(get_db)):
    if body.parent_id:
        parent = db.query(NetObjectModel).filter(NetObjectModel.id == body.parent_id).first()
        if not parent:
            raise HTTPException(status_code=422, detail=f'parent_id {body.parent_id!r} not found')
    now = datetime.now(timezone.utc)
    obj = NetObjectModel(
        id=f'obj_{uuid4().hex[:8]}',
        name=body.name,
        slug=_slugify(body.name),
        type=body.type,
        parent_id=body.parent_id,
        status=body.status,
        vendor=body.vendor,
        model=body.model,
        serial=body.serial,
        notes=body.notes,
        created_at=now,
        updated_at=now,
    )
    db.add(obj)
    db.commit()
    db.refresh(obj)
    return EntityResponse(item=_to_net_object(obj))


@router.put('/{object_id}', response_model=EntityResponse[NetObject])
def replace_object(object_id: str, body: NetObjectCreate, db: Session = Depends(get_db)):
    row = db.query(NetObjectModel).filter(NetObjectModel.id == object_id).first()
    if not row:
        raise HTTPException(status_code=404, detail='Object not found')
    if body.parent_id and body.parent_id != row.parent_id:
        parent = db.query(NetObjectModel).filter(NetObjectModel.id == body.parent_id).first()
        if not parent:
            raise HTTPException(status_code=422, detail=f'parent_id {body.parent_id!r} not found')
    row.name = body.name
    row.slug = _slugify(body.name)
    row.type = body.type
    row.parent_id = body.parent_id
    row.status = body.status
    row.vendor = body.vendor
    row.model = body.model
    row.serial = body.serial
    row.notes = body.notes
    row.updated_at = datetime.now(timezone.utc)
    db.commit()
    db.refresh(row)
    return EntityResponse(item=_to_net_object(row))


@router.patch('/{object_id}', response_model=EntityResponse[NetObject])
def update_object(object_id: str, body: NetObjectUpdate, db: Session = Depends(get_db)):
    row = db.query(NetObjectModel).filter(NetObjectModel.id == object_id).first()
    if not row:
        raise HTTPException(status_code=404, detail='Object not found')
    data = body.model_dump(exclude_unset=True)
    if 'parent_id' in data and data['parent_id']:
        parent = db.query(NetObjectModel).filter(NetObjectModel.id == data['parent_id']).first()
        if not parent:
            raise HTTPException(status_code=422, detail=f'parent_id {data["parent_id"]!r} not found')
    if 'name' in data:
        row.slug = _slugify(data['name'])
    for field, value in data.items():
        setattr(row, field, value)
    row.updated_at = datetime.now(timezone.utc)
    db.commit()
    db.refresh(row)
    return EntityResponse(item=_to_net_object(row))


@router.delete('/{object_id}', status_code=204)
def delete_object(object_id: str, db: Session = Depends(get_db)):
    row = db.query(NetObjectModel).filter(NetObjectModel.id == object_id).first()
    if not row:
        raise HTTPException(status_code=404, detail='Object not found')
    children = db.query(NetObjectModel).filter(NetObjectModel.parent_id == object_id).count()
    if children:
        raise HTTPException(
            status_code=409,
            detail=f'Cannot delete: object has {children} child object(s). Remove or re-parent them first.',
        )
    db.delete(row)
    db.commit()