from typing import List

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

from app.db.models import InventoryItem
from app.db.session import get_db
from app.schemas.inventory import InventoryItem as InventoryItemSchema
from app.schemas.inventory import InventoryItemCreate, InventoryItemUpdate

router = APIRouter()

@router.get("/", response_model=List[InventoryItemSchema])
def get_inventory_items(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
    items = db.query(InventoryItem).offset(skip).limit(limit).all()
    return items

@router.get("/{item_id}", response_model=InventoryItemSchema)
def get_inventory_item(item_id: int, db: Session = Depends(get_db)):
    item = db.query(InventoryItem).filter(InventoryItem.id == item_id).first()
    if not item:
        raise HTTPException(status_code=404, detail="Item not found")
    return item

@router.post("/", response_model=InventoryItemSchema)
def create_inventory_item(item: InventoryItemCreate, db: Session = Depends(get_db)):
    existing_item = db.query(InventoryItem).filter(InventoryItem.sku == item.sku).first()
    if existing_item:
        raise HTTPException(status_code=400, detail="SKU already exists")

    db_item = InventoryItem(**item.dict())
    db.add(db_item)
    db.commit()
    db.refresh(db_item)
    return db_item

@router.put("/{item_id}", response_model=InventoryItemSchema)
def update_inventory_item(item_id: int, item: InventoryItemUpdate, db: Session = Depends(get_db)):
    db_item = db.query(InventoryItem).filter(InventoryItem.id == item_id).first()
    if not db_item:
        raise HTTPException(status_code=404, detail="Item not found")

    update_data = item.dict(exclude_unset=True)
    for field, value in update_data.items():
        setattr(db_item, field, value)

    db.commit()
    db.refresh(db_item)
    return db_item

@router.delete("/{item_id}")
def delete_inventory_item(item_id: int, db: Session = Depends(get_db)):
    db_item = db.query(InventoryItem).filter(InventoryItem.id == item_id).first()
    if not db_item:
        raise HTTPException(status_code=404, detail="Item not found")

    db.delete(db_item)
    db.commit()
    return {"message": "Item deleted successfully"}

@router.get("/low-stock/", response_model=List[InventoryItemSchema])
def get_low_stock_items(db: Session = Depends(get_db)):
    items = db.query(InventoryItem).filter(InventoryItem.quantity <= InventoryItem.minimum_stock).all()
    return items