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

from app.db.session import get_db
from app.crud import category as category_crud
from app.schemas.category import Category, CategoryCreate, CategoryUpdate

router = APIRouter()


@router.get("/", response_model=List[Category])
def read_categories(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
    """
    Retrieve categories.
    """
    categories = category_crud.get_categories(db, skip=skip, limit=limit)
    return categories


@router.post("/", response_model=Category, status_code=status.HTTP_201_CREATED)
def create_category(category: CategoryCreate, db: Session = Depends(get_db)):
    """
    Create new category.
    """
    # Check if category with same name already exists
    existing_category = category_crud.get_category_by_name(db, name=category.name)
    if existing_category:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Category with this name already exists",
        )

    return category_crud.create_category(db=db, category=category)


@router.get("/{category_id}", response_model=Category)
def read_category(category_id: int, db: Session = Depends(get_db)):
    """
    Get category by ID.
    """
    db_category = category_crud.get_category(db, category_id=category_id)
    if db_category is None:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Category not found"
        )
    return db_category


@router.put("/{category_id}", response_model=Category)
def update_category(
    category_id: int, category: CategoryUpdate, db: Session = Depends(get_db)
):
    """
    Update category.
    """
    # Check if category exists
    db_category = category_crud.get_category(db, category_id=category_id)
    if db_category is None:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Category not found"
        )

    # Check if name is being updated and already exists
    if category.name and category.name != db_category.name:
        existing_category = category_crud.get_category_by_name(db, name=category.name)
        if existing_category:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail="Category with this name already exists",
            )

    return category_crud.update_category(
        db=db, category_id=category_id, category=category
    )


@router.delete("/{category_id}", status_code=status.HTTP_204_NO_CONTENT)
def delete_category(category_id: int, db: Session = Depends(get_db)):
    """
    Delete category.
    """
    success = category_crud.delete_category(db=db, category_id=category_id)
    if not success:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Category not found"
        )