/**
 * @license
 * Copyright 2019 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { ComponentContainer } from './component_container';

export const enum InstantiationMode {
  LAZY = 'LAZY', // Currently most components are LAZY in JS SDK
  EAGER = 'EAGER', // EAGER components are initialized immediately upon registration
  EXPLICIT = 'EXPLICIT' // component needs to be initialized explicitly by calling Provider.initialize()
}

/**
 * PUBLIC: A public component provides a set of public APIs to customers. A service namespace will be patched
 * onto `firebase` namespace. Assume the component name is `test`, customers will be able
 * to get the service by calling `firebase.test()` or `app.test()` where `app` is a `FirebaseApp` instance.
 *
 * PRIVATE: A private component provides a set of private APIs that are used internally by other
 * Firebase SDKs. No serivce namespace is created in `firebase` namespace and customers have no way to get them.
 */
export const enum ComponentType {
  PUBLIC = 'PUBLIC',
  PRIVATE = 'PRIVATE',
  VERSION = 'VERSION'
}

export interface InstanceFactoryOptions {
  instanceIdentifier?: string;
  options?: {};
}

export type InitializeOptions = InstanceFactoryOptions;

/**
 * Factory to create an instance of type T, given a ComponentContainer.
 * ComponentContainer is the IOC container that provides {@link Provider}
 * for dependencies.
 *
 * NOTE: The container only provides {@link Provider} rather than the actual instances of dependencies.
 * It is useful for lazily loaded dependencies and optional dependencies.
 */
export type InstanceFactory<T extends Name> = (
  container: ComponentContainer,
  options: InstanceFactoryOptions
) => NameServiceMapping[T];

export type onInstanceCreatedCallback<T extends Name> = (
  container: ComponentContainer,
  instanceIdentifier: string,
  instance: NameServiceMapping[T]
) => void;

export interface Dictionary {
  [key: string]: unknown;
}

/**
 * This interface will be extended by Firebase SDKs to provide service name and service type mapping.
 * It is used as a generic constraint to ensure type safety.
 */
export interface NameServiceMapping {}

export type Name = keyof NameServiceMapping;
export type Service = NameServiceMapping[Name];

export type OnInitCallBack<T extends Name> = (
  instance: NameServiceMapping[T],
  identifier: string
) => void;