from typing import Any, Dict, Generic, List, Optional, Type, TypeVar, Union

from fastapi.encoders import jsonable_encoder
from pydantic import BaseModel
from sqlalchemy.orm import Session

from app.core.database import Base

ModelType = TypeVar("ModelType", bound=Base)
CreateSchemaType = TypeVar("CreateSchemaType", bound=BaseModel)
UpdateSchemaType = TypeVar("UpdateSchemaType", bound=BaseModel)


class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
    """Base class for CRUD operations."""

    def __init__(self, model: Type[ModelType]):
        """Initialize with sqlalchemy model.

        Args:
            model: The SQLAlchemy model
        """
        self.model = model

    def get(self, db: Session, id: Any) -> Optional[ModelType]:
        """Get a record by ID.

        Args:
            db: Database session
            id: ID of the record to get

        Returns:
            The record if found, None otherwise
        """
        return db.query(self.model).filter(self.model.id == id).first()

    def get_multi(
        self, db: Session, *, skip: int = 0, limit: int = 100
    ) -> List[ModelType]:
        """Get multiple records.

        Args:
            db: Database session
            skip: Number of records to skip
            limit: Maximum number of records to return

        Returns:
            List of records
        """
        return db.query(self.model).offset(skip).limit(limit).all()

    def create(self, db: Session, *, obj_in: CreateSchemaType) -> ModelType:
        """Create a new record.

        Args:
            db: Database session
            obj_in: Schema with data to create

        Returns:
            The created record
        """
        obj_in_data = jsonable_encoder(obj_in)
        db_obj = self.model(**obj_in_data)
        db.add(db_obj)
        db.commit()
        db.refresh(db_obj)
        return db_obj

    def update(
        self,
        db: Session,
        *,
        db_obj: ModelType,
        obj_in: Union[UpdateSchemaType, Dict[str, Any]]
    ) -> ModelType:
        """Update a record.

        Args:
            db: Database session
            db_obj: The database object to update
            obj_in: Schema with data to update

        Returns:
            The updated record
        """
        obj_data = jsonable_encoder(db_obj)
        if isinstance(obj_in, dict):
            update_data = obj_in
        else:
            update_data = obj_in.model_dump(exclude_unset=True)
        for field in obj_data:
            if field in update_data:
                setattr(db_obj, field, update_data[field])
        db.add(db_obj)
        db.commit()
        db.refresh(db_obj)
        return db_obj

    def remove(self, db: Session, *, id: int) -> ModelType:
        """Remove a record.

        Args:
            db: Database session
            id: ID of the record to remove

        Returns:
            The removed record
        """
        obj = db.query(self.model).get(id)
        db.delete(obj)
        db.commit()
        return obj