/**
 * Copyright 2025 Phenix Real Time Solutions, Inc. Confidential and Proprietary. All Rights Reserved.
 */

import {Type} from './Type';
import type {IDependencyProvider} from './IDependencyProvider';

/**
 * A dependency provider for pre-existing instances.
 */
export class InstanceProvider implements IDependencyProvider {
  private readonly _type: Type;
  private readonly _instance: unknown;

  constructor(type: Type, instance: unknown) {
    if (!(type instanceof Type)) {
      throw new Error('Must provide a valid type');
    }

    if (instance === null || instance === undefined) {
      throw new Error('Must provide a valid instance');
    }

    this._type = type;
    this._instance = instance;
  }

  canProvide(type: Type): boolean {
    if (!(type instanceof Type)) {
      throw new Error('Must provide a valid type');
    }

    return type.equals(this._type);
  }

  async provide(type: Type): Promise<unknown> {
    if (!(type instanceof Type)) {
      throw new Error('Must provide a valid type');
    }

    return this._instance;
  }

  toString(): string {
    return 'InstanceProvider';
  }
}