from typing import Any, List

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

from app import crud
from app.api import deps
from app.models.user import User
from app.schemas.supplier import Supplier, SupplierCreate, SupplierUpdate

router = APIRouter()


@router.get("/", response_model=List[Supplier])
def read_suppliers(
    db: Session = Depends(deps.get_db),
    skip: int = 0,
    limit: int = 100,
    current_user: User = Depends(deps.get_current_user),
) -> Any:
    """
    Retrieve suppliers.
    """
    suppliers = crud.supplier.get_multi(db, skip=skip, limit=limit)
    return suppliers


@router.post("/", response_model=Supplier, status_code=status.HTTP_201_CREATED)
def create_supplier(
    *,
    db: Session = Depends(deps.get_db),
    supplier_in: SupplierCreate,
    current_user: User = Depends(deps.get_current_user),
) -> Any:
    """
    Create new supplier.
    """
    # Check if supplier with the same email already exists (if email is provided)
    if supplier_in.email:
        supplier = crud.supplier.get_by_email(db, email=supplier_in.email)
        if supplier:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail="Supplier with this email already exists",
            )
    
    supplier = crud.supplier.create(db, obj_in=supplier_in)
    return supplier


@router.get("/{supplier_id}", response_model=Supplier)
def read_supplier(
    *,
    db: Session = Depends(deps.get_db),
    supplier_id: int,
    current_user: User = Depends(deps.get_current_user),
) -> Any:
    """
    Get supplier by ID.
    """
    supplier = crud.supplier.get(db, id=supplier_id)
    if not supplier:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Supplier not found",
        )
    return supplier


@router.put("/{supplier_id}", response_model=Supplier)
def update_supplier(
    *,
    db: Session = Depends(deps.get_db),
    supplier_id: int,
    supplier_in: SupplierUpdate,
    current_user: User = Depends(deps.get_current_user),
) -> Any:
    """
    Update a supplier.
    """
    supplier = crud.supplier.get(db, id=supplier_id)
    if not supplier:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Supplier not found",
        )
    
    # Check if email is being changed and if it already exists
    if supplier_in.email and supplier_in.email != supplier.email:
        existing_supplier = crud.supplier.get_by_email(db, email=supplier_in.email)
        if existing_supplier and existing_supplier.id != supplier_id:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail="Supplier with this email already exists",
            )
    
    supplier = crud.supplier.update(db, db_obj=supplier, obj_in=supplier_in)
    return supplier


@router.delete("/{supplier_id}", status_code=status.HTTP_204_NO_CONTENT, response_model=None)
def delete_supplier(
    *,
    db: Session = Depends(deps.get_db),
    supplier_id: int,
    current_user: User = Depends(deps.get_current_user),
) -> Any:
    """
    Delete a supplier.
    """
    supplier = crud.supplier.get(db, id=supplier_id)
    if not supplier:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Supplier not found",
        )
    
    # Check if any items are using this supplier
    items = crud.item.get_by_supplier(db, supplier_id=supplier_id, skip=0, limit=1)
    if items:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Cannot delete supplier with associated items",
        )
    
    crud.supplier.remove(db, id=supplier_id)
    return None