// (C) Copyright 2015 Moodle Pty Ltd.
//
// 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 { ApplicationRef, ApplicationInitStatus, Injector, NgZone as NgZoneService, Type } from '@angular/core';
import { Router as RouterService } from '@angular/router';
import { HttpClient } from '@angular/common/http';

import {
    Platform as PlatformService,
    AlertController as AlertControllerService,
    LoadingController as LoadingControllerService,
    ModalController as ModalControllerService,
    ToastController as ToastControllerService,
    GestureController as GestureControllerService,
    ActionSheetController as ActionSheetControllerService,
    NavController as NavControllerService,
    PopoverController as PopoverControllerService,
} from '@ionic/angular';

import { Badge as BadgeService } from '@ionic-native/badge/ngx';
import { Camera as CameraService } from '@ionic-native/camera/ngx';
import { Chooser as ChooserService } from '@ionic-native/chooser/ngx';
import { Clipboard as ClipboardService } from '@ionic-native/clipboard/ngx';
import { Diagnostic as DiagnosticService } from '@ionic-native/diagnostic/ngx';
import { Device as DeviceService } from '@ionic-native/device/ngx';
import { File as FileService } from '@ionic-native/file/ngx';
import { FileOpener as FileOpenerService } from '@ionic-native/file-opener/ngx';
import { FileTransfer as FileTransferService } from '@ionic-native/file-transfer/ngx';
import { Geolocation as GeolocationService } from '@ionic-native/geolocation/ngx';
import { HTTP } from '@ionic-native/http/ngx';
import { InAppBrowser as InAppBrowserService } from '@ionic-native/in-app-browser/ngx';
import { WebView as WebViewService } from '@ionic-native/ionic-webview/ngx';
import { Keyboard as KeyboardService } from '@ionic-native/keyboard/ngx';
import { LocalNotifications as LocalNotificationsService } from '@ionic-native/local-notifications/ngx';
import { Media as MediaService } from '@ionic-native/media/ngx';
import { MediaCapture as MediaCaptureService } from '@ionic-native/media-capture/ngx';
import { Network as NetworkService } from '@ionic-native/network/ngx';
import { Push as PushService } from '@ionic-native/push/ngx';
import { QRScanner as QRScannerService } from '@ionic-native/qr-scanner/ngx';
import { StatusBar as StatusBarService } from '@ionic-native/status-bar/ngx';
import { SplashScreen as SplashScreenService } from '@ionic-native/splash-screen/ngx';
import { SQLite as SQLiteService } from '@ionic-native/sqlite/ngx';
import { WebIntent as WebIntentService } from '@ionic-native/web-intent/ngx';
import { Zip as ZipService } from '@ionic-native/zip/ngx';

import { TranslateService } from '@ngx-translate/core';

const OBJECT_PROTOTYPE = Object.getPrototypeOf(Object);

/**
 * Injector instance used to resolve singletons.
 */
let singletonsInjector: Injector | null = null;

/**
 * Helper to get service class methods.
 */
type GetMethods<T> = {
    [K in keyof T]: T[K] extends (...args: unknown[]) => unknown ? K : never;
}[keyof T];

/**
 * Singleton proxy created using the factory method.
 *
 * @see makeSingleton
 */
export type CoreSingletonProxy<Service, Getters extends keyof Service = never> =
    Pick<Service, GetMethods<Service>> &
    Pick<Service, Getters> &
    {
        instance: Service;
        setInstance(instance: Service): void;
    };

/**
 * Set the injector that will be used to resolve instances in the singletons of this module.
 *
 * @param injector Module injector.
 */
export function setSingletonsInjector(injector: Injector): void {
    singletonsInjector = injector;
}

/**
 * Make a singleton proxy for the given injection token.
 *
 * This method will return an object that will proxy method calls to an underlying service instance. Getters will also be proxied,
 * but these need to be configured manually using the `getters` argument. Most of the time, this proxy can be used directly like
 * you would use a service instance. If you need to get the real service instance, it can be accessed through the `instance`
 * property and it can be set with the `setInstance` method.
 *
 * @param injectionToken Injection token used to resolve the service. This is usually the service class if the provider was
 * defined using a class or the string used in the `provide` key if it was defined using an object.
 * @param getters Getter names to proxy.
 * @return Singleton proxy.
 */
export function makeSingleton<Service>(injectionToken: Type<Service> | Type<unknown> | string): CoreSingletonProxy<Service, never>;
export function makeSingleton<Service, Getters extends keyof Service>(
    injectionToken: Type<Service> | Type<unknown> | string,
    getters: Getters[],
): CoreSingletonProxy<Service, Getters>;
export function makeSingleton<Service, Getters extends keyof Service>(
    injectionToken: Type<Service> | Type<unknown> | string,
    getters: Getters[] = [],
): CoreSingletonProxy<Service, Getters> {
    // Define instance manipulation affordances.
    const proxy = {
        setInstance(instance: Service) {
            Object.defineProperty(proxy, 'instance', {
                value: instance,
                configurable: true,
            });
        },
    } as CoreSingletonProxy<Service, Getters>;

    Object.defineProperty(proxy, 'instance', {
        get: () => {
            if (!singletonsInjector) {
                throw new Error('Can\'t resolve a singleton instance without an injector');
            }

            const instance = singletonsInjector.get(injectionToken);

            proxy.setInstance(instance);

            return instance;
        },
        configurable: true,
    });

    // Define method and getter proxies.
    if (isServiceClass(injectionToken)) {
        // Get property descriptors, going all the way up the prototype chain (for services extending other classes).
        let parentPrototype = injectionToken;
        let descriptors: Record<string, PropertyDescriptor> = {};

        do {
            descriptors = {
                ...Object.getOwnPropertyDescriptors(parentPrototype.prototype),
                ...descriptors,
            };

            parentPrototype = Object.getPrototypeOf(parentPrototype);
        } while (parentPrototype !== OBJECT_PROTOTYPE);

        // Don't proxy constructor calls.
        delete descriptors['constructor'];

        // Define method proxies.
        for (const [property, descriptor] of Object.entries(descriptors)) {
            // Skip getters and setters.
            if (descriptor.get || descriptor.set) {
                continue;
            }

            // Define method proxy.
            Object.defineProperty(proxy, property, {
                value: (...args) => proxy.instance[property].call(proxy.instance, ...args),
                configurable: true,
            });
        }

        // Define getter proxies.
        for (const getter of getters) {
            Object.defineProperty(proxy, getter, { get: () => proxy.instance[getter] });
        }
    }

    return proxy;
}

/**
 * Type guard to check if an injection token is a service class.
 *
 * @param injectionToken Injection token.
 * @return Whether the token is a class.
 */
function isServiceClass(injectionToken: Type<unknown> | string): injectionToken is Type<unknown> {
    return typeof injectionToken !== 'string';
}

// Convert ionic-native services to singleton.
export class Badge extends makeSingleton(BadgeService) {}
export class Camera extends makeSingleton(CameraService) {}
export class Chooser extends makeSingleton(ChooserService) {}
export class Clipboard extends makeSingleton(ClipboardService) {}
export class Device extends makeSingleton(DeviceService) {}
export class Diagnostic extends makeSingleton(DiagnosticService) {}
export class File extends makeSingleton(FileService) {}
export class FileOpener extends makeSingleton(FileOpenerService) {}
export class FileTransfer extends makeSingleton(FileTransferService) {}
export class Geolocation extends makeSingleton(GeolocationService) {}
export class InAppBrowser extends makeSingleton(InAppBrowserService) {}
export class Keyboard extends makeSingleton(KeyboardService) {}
export class LocalNotifications extends makeSingleton(LocalNotificationsService) {}
export class Media extends makeSingleton(MediaService) {}
export class MediaCapture extends makeSingleton(MediaCaptureService) {}
export class NativeHttp extends makeSingleton(HTTP) {}
export class Network extends makeSingleton(NetworkService) {}
export class Push extends makeSingleton(PushService) {}
export class QRScanner extends makeSingleton(QRScannerService) {}
export class StatusBar extends makeSingleton(StatusBarService) {}
export class SplashScreen extends makeSingleton(SplashScreenService) {}
export class SQLite extends makeSingleton(SQLiteService) {}
export class WebIntent extends makeSingleton(WebIntentService) {}
export class WebView extends makeSingleton(WebViewService) {}
export class Zip extends makeSingleton(ZipService) {}

// Convert some Angular and Ionic injectables to singletons.
export class NgZone extends makeSingleton(NgZoneService) {}
export class Http extends makeSingleton(HttpClient) {}
export class Platform extends makeSingleton(PlatformService) {}
export class ActionSheetController extends makeSingleton(ActionSheetControllerService) {}
export class AlertController extends makeSingleton(AlertControllerService) {}
export class LoadingController extends makeSingleton(LoadingControllerService) {}
export class ModalController extends makeSingleton(ModalControllerService) {}
export class PopoverController extends makeSingleton(PopoverControllerService) {}
export class ToastController extends makeSingleton(ToastControllerService) {}
export class GestureController extends makeSingleton(GestureControllerService) {}
export class ApplicationInit extends makeSingleton(ApplicationInitStatus) {}
export class Application extends makeSingleton(ApplicationRef) {}
export class NavController extends makeSingleton(NavControllerService) {}
export class Router extends makeSingleton(RouterService) {}

// Convert external libraries injectables.
export class Translate extends makeSingleton(TranslateService) {

    static instant(key: string | Array<string>, interpolateParams?: Record<string, unknown>): string | any {
        return this.instance.instant(key, interpolateParams);
    }

}