import type { EntityTarget } from 'typeorm';
import { getRepository } from '../../core/database';

export function getDeserializedEntityPromise<T>(serializedProperty: number, entityTarget: EntityTarget<T>): Promise<T>;
export function getDeserializedEntityPromise<T>(
  serializedProperty: undefined,
  entityTarget: EntityTarget<T>,
): undefined;
export function getDeserializedEntityPromise<T>(serializedProperty: null, entityTarget: EntityTarget<T>): null;
export function getDeserializedEntityPromise<T>(
  serializedProperty: number | undefined,
  entityTarget: EntityTarget<T>,
): Promise<T> | undefined;
export function getDeserializedEntityPromise<T>(
  serializedProperty: number | undefined | null,
  entityTarget: EntityTarget<T>,
): Promise<T> | undefined | null;
export function getDeserializedEntityPromise<T>(
  serializedProperty: number | undefined | null,
  entityTarget: EntityTarget<T>,
): Promise<T> | undefined | null {
  return serializedProperty === null
    ? null
    : serializedProperty
    ? getRepository(entityTarget).then((repo) => repo.findOneOrFail(serializedProperty))
    : undefined;
}

export function getDeserializedEntitiesPromise<T>(
  serializedProperty: number[],
  entityTarget: EntityTarget<T>,
): Promise<T[]>;
export function getDeserializedEntitiesPromise<T>(
  serializedProperty: undefined,
  entityTarget: EntityTarget<T>,
): undefined;
export function getDeserializedEntitiesPromise<T>(
  serializedProperty: number[] | undefined,
  entityTarget: EntityTarget<T>,
): Promise<T[]> | undefined;
export function getDeserializedEntitiesPromise<T>(
  serializedProperty: number[] | undefined,
  entityTarget: EntityTarget<T>,
): Promise<T[]> | undefined {
  return serializedProperty
    ? Promise.all(serializedProperty.map((id) => getRepository(entityTarget).then((repo) => repo.findOneOrFail(id))))
    : undefined;
}