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.db.base_class import Base

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


class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
    def __init__(self, model: Type[ModelType]):
        """
        CRUD object with default methods to Create, Read, Update, Delete (CRUD).
        """
        self.model = model

    def get(self, db: Session, id: Any) -> Optional[ModelType]:
        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]:
        return db.query(self.model).offset(skip).limit(limit).all()

    def create(self, db: Session, *, obj_in: CreateSchemaType) -> ModelType:
        try:
            obj_in_data = jsonable_encoder(obj_in)
            print(f"Creating {self.model.__name__} with data: {obj_in_data}")

            db_obj = self.model(**obj_in_data)
            db.add(db_obj)
            db.commit()
            db.refresh(db_obj)

            print(f"Successfully created {self.model.__name__} with id: {db_obj.id}")
            return db_obj
        except Exception as e:
            db.rollback()
            error_msg = f"Error creating {self.model.__name__}: {str(e)}"
            print(error_msg)
            import traceback

            print(traceback.format_exc())
            raise Exception(error_msg) from e

    def update(
        self,
        db: Session,
        *,
        db_obj: ModelType,
        obj_in: Union[UpdateSchemaType, Dict[str, Any]],
    ) -> ModelType:
        try:
            # Log update operation
            print(f"Updating {self.model.__name__} with id: {db_obj.id}")

            # Get the existing data
            obj_data = jsonable_encoder(db_obj)

            # Process the update data
            if isinstance(obj_in, dict):
                update_data = obj_in
            else:
                # Handle both Pydantic v1 and v2
                if hasattr(obj_in, "model_dump"):
                    update_data = obj_in.model_dump(exclude_unset=True)
                else:
                    update_data = obj_in.dict(exclude_unset=True)

            # Log the changes being made
            changes = {k: v for k, v in update_data.items() if k in obj_data}
            print(f"Fields to update: {changes}")

            # Apply the updates
            for field in obj_data:
                if field in update_data:
                    setattr(db_obj, field, update_data[field])

            # Save changes
            db.add(db_obj)
            db.commit()
            db.refresh(db_obj)

            print(f"Successfully updated {self.model.__name__} with id: {db_obj.id}")
            return db_obj

        except Exception as e:
            db.rollback()
            error_msg = f"Error updating {self.model.__name__}: {str(e)}"
            print(error_msg)
            import traceback

            print(traceback.format_exc())
            raise Exception(error_msg) from e

    def remove(self, db: Session, *, id: int) -> ModelType:
        try:
            # Get the object first
            obj = db.query(self.model).filter(self.model.id == id).first()
            if not obj:
                print(f"{self.model.__name__} with id {id} not found for deletion")
                return None

            print(f"Deleting {self.model.__name__} with id: {id}")

            # Delete the object
            db.delete(obj)
            db.commit()

            print(f"Successfully deleted {self.model.__name__} with id: {id}")
            return obj

        except Exception as e:
            db.rollback()
            error_msg = f"Error deleting {self.model.__name__}: {str(e)}"
            print(error_msg)
            import traceback

            print(traceback.format_exc())
            raise Exception(error_msg) from e