cothema / ionic-universal-firebase-login

import { Injectable } from '@angular/core';

import { Cacheable } from 'ngx-cacheable';

import { from, Observable } from 'rxjs';

import { UserModel } from '..';

import { FirebaseStorage } from './firebase-storage';

import { IStorageProvider } from './i-storage-provider';

import { IStorageProviderOptions } from './i-storage-provider-options';

import { InMemoryStorage } from './in-memory-storage.service';

@Injectable({

    providedIn: 'root',

})

export class StorageProvider<User extends UserModel = UserModel> {

    options: IStorageProviderOptions = {

        userTable: 'users',

        storage: false,

    }

    public constructor(

        private firebaseStorage: FirebaseStorage<User>,

        private inMemoryStorage: InMemoryStorage

    ) {

    }

    /**

     * Get user from cache if possible or from a storage

     */

    @Cacheable()

    public getUser(): Observable<User | unknown | null> {

        const storageProvider = this.getProvider();

        if (storageProvider !== null) {

            return from(storageProvider.fetchUser());

        }

        throw new Error('No storage provider found.');

    }

    public getProvider() {

        return this.getProviderById(this.options.storage);

    }

    protected getProviderById(

        providerId: false | 'firestore',

    ): IStorageProvider<User> {

        let provider;

        switch (providerId) {

            case 'firestore':

                provider = this.firebaseStorage;

                provider.options.userTable = this.options.userTable;

                break;

            case false:

                provider = this.inMemoryStorage;

                break;

        }

        if (provider !== undefined) {

            return provider;

        }

        throw new Error(`Provider ${providerId} not supported.`);

    }

}