from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.orm import Session, joinedload
from uuid import UUID
from database import get_db
import models
from schemas import ItemCreate, ItemOut

router = APIRouter(prefix="/items", tags=["items"])

@router.get("/", response_model=list[ItemOut])
def list_items(db: Session = Depends(get_db)):
    items = (
        db.query(models.Item)
        .options(joinedload(models.Item.tags).joinedload(models.ItemTag.tag))
        .all()
    )
    # pydantic can handle relationships if orm_mode
    return [
        models.Item(
            id=it.id,
            user_id=it.user_id,
            name=it.name,
            tags=it.tags,
        ) for it in items
    ]

@router.post("/", response_model=ItemOut)
def create_item(payload: ItemCreate, db: Session = Depends(get_db)):
    user = db.query(models.User).first()
    if not user:
        from uuid import uuid4
        user = models.User(id=uuid4(), name="Demo")
        db.add(user)
        db.flush()

    item = models.Item(user_id=user.id, name=payload.name)

    if payload.tag_ids:
        links = []
        tags = db.query(models.Tag).filter(models.Tag.id.in_(payload.tag_ids), models.Tag.user_id == user.id).all()
        for t in tags:
            links.append(models.ItemTag(item=item, tag=t))
        item.tags = links

    db.add(item)
    db.commit()
    db.refresh(item)

    # eager load for response
    item = (
        db.query(models.Item)
        .options(joinedload(models.Item.tags).joinedload(models.ItemTag.tag))
        .get(item.id)
    )
    return item

@router.delete("/{item_id}", status_code=204)
def delete_item(item_id: UUID, db: Session = Depends(get_db)):
    item = db.get(models.Item, item_id)
    if not item:
        raise HTTPException(status_code=404, detail="Item not found")
    db.delete(item)
    db.commit()