/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the Source EULA. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

import * as azdata from 'azdata';
import { Event, Emitter } from 'vs/base/common/event';
import { IAccountManagementService } from 'sql/platform/accounts/common/interfaces';
import { AccountProviderAddedEventParams, UpdateAccountListEventParams } from 'sql/platform/accounts/common/eventTypes';
import { coalesce } from 'vs/base/common/arrays';

/**
 * View model for account dialog
 */
export class AccountViewModel {
	// EVENTING ///////////////////////////////////////////////////////
	private _addProviderEmitter: Emitter<AccountProviderAddedEventParams>;
	public get addProviderEvent(): Event<AccountProviderAddedEventParams> { return this._addProviderEmitter.event; }

	private _removeProviderEmitter: Emitter<azdata.AccountProviderMetadata>;
	public get removeProviderEvent(): Event<azdata.AccountProviderMetadata> { return this._removeProviderEmitter.event; }

	private _updateAccountListEmitter: Emitter<UpdateAccountListEventParams>;
	public get updateAccountListEvent(): Event<UpdateAccountListEventParams> { return this._updateAccountListEmitter.event; }

	constructor(@IAccountManagementService private _accountManagementService: IAccountManagementService) {
		// Create our event emitters
		this._addProviderEmitter = new Emitter<AccountProviderAddedEventParams>();
		this._removeProviderEmitter = new Emitter<azdata.AccountProviderMetadata>();
		this._updateAccountListEmitter = new Emitter<UpdateAccountListEventParams>();

		// Register handlers for any changes to the providers or accounts
		this._accountManagementService.addAccountProviderEvent(arg => this._addProviderEmitter.fire(arg));
		this._accountManagementService.removeAccountProviderEvent(arg => this._removeProviderEmitter.fire(arg));
		this._accountManagementService.updateAccountListEvent(arg => this._updateAccountListEmitter.fire(arg));
	}

	// PUBLIC METHODS //////////////////////////////////////////////////////
	/**
	 * Loads an initial list of account providers and accounts from the account management service
	 * and fires an event after each provider/accounts has been loaded.
	 *
	 */
	public initialize(): Thenable<AccountProviderAddedEventParams[]> {
		// Load a baseline of the account provider metadata and accounts
		// 1) Get all the providers from the account management service
		// 2) For each provider, get the accounts
		// 3) Build parameters to add a provider and return it
		return this._accountManagementService.getAccountProviderMetadata()
			.then(
				(providers: azdata.AccountProviderMetadata[]) => {
					const promises = providers.map(provider => {
						return this._accountManagementService.getAccountsForProvider(provider.id)
							.then(
								accounts => <AccountProviderAddedEventParams>{
									addedProvider: provider,
									initialAccounts: accounts
								},
								() => { /* Swallow failures at getting accounts, we'll just hide that provider */ });
					});
					return Promise.all(promises).then(accounts => coalesce(accounts));
				}, () => {
					/* Swallow failures and just pretend we don't have any providers */
					return [];
				});
	}
}