/*
Copyright 2021 The Matrix.org Foundation C.I.C.

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 {Options as BaseOptions, ViewModel} from "./ViewModel";
import {Client} from "../matrix/Client.js";
import {SegmentType} from "./navigation/index";

type Options = { sessionId: string; } & BaseOptions;

export class ForcedLogoutViewModel extends ViewModel<SegmentType, Options> {
    private _sessionId: string;
    private _error?: Error;
    private _logoutPromise: Promise<void>;
    private _showStatus: boolean = false;
    private _showSpinner: boolean = false;

    constructor(options: Options) {
        super(options);
        this._sessionId = options.sessionId;
        // Start the logout process immediately without any user interaction
        this._logoutPromise = this.forceLogout();
    }

    async forceLogout(): Promise<void> {
        try {
            const client = new Client(this.platform);
            await client.startForcedLogout(this._sessionId);
        }
        catch (err) {
            this._error = err;
            // Show the error in the UI 
            this._showSpinner = false;
            this._showStatus = true;
            this.emitChange("error");
        }
    }

    async proceed(): Promise<void> {
        /**
         * The logout should already be completed because we started it from the ctor.
         * In case the logout is still proceeding, we will show a message with a spinner. 
         */
        this._showSpinner = true;
        this._showStatus = true;
        this.emitChange("showStatus");
        await this._logoutPromise;
        // At this point, the logout is completed for sure.
        if (!this._error) {
            this.navigation.push("login", true);
        }
    }

    get status(): string {
        if (this._error) {
            return this.i18n`Could not log out of device: ${this._error.message}`;
        } else {
            return this.i18n`Logging out… Please don't close the app.`;
        }
    }

    get showStatus(): boolean {
        return this._showStatus;
    }

    get showSpinner(): boolean {
        return this._showSpinner;
    }
}