/*
Copyright 2017-2024 New Vector Ltd.
Copyright 2016 Aviral Dasgupta
Copyright 2016 OpenMarket Ltd

SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
Please see LICENSE files in the repository root for full details.
*/

import UAParser from "ua-parser-js";
import { logger } from "matrix-js-sdk/src/logger";

import { MatrixClientPeg } from "../../MatrixClientPeg";
import { UpdateCheckStatus, UpdateStatus } from "../../BasePlatform";
import dis from "../../dispatcher/dispatcher";
import { hideToast as hideUpdateToast, showToast as showUpdateToast } from "../../toasts/UpdateToast";
import { Action } from "../../dispatcher/actions";
import { CheckUpdatesPayload } from "../../dispatcher/payloads/CheckUpdatesPayload";
import VectorBasePlatform from "./VectorBasePlatform";
import { parseQs } from "../url_utils";
import { _t } from "../../languageHandler";

const POKE_RATE_MS = 10 * 60 * 1000; // 10 min

function getNormalizedAppVersion(version: string): string {
    // if version looks like semver with leading v, strip it (matches scripts/normalize-version.sh)
    const semVerRegex = /^v\d+.\d+.\d+(-.+)?$/;
    if (semVerRegex.test(version)) {
        return version.substring(1);
    }
    return version;
}

export default class WebPlatform extends VectorBasePlatform {
    private static readonly VERSION = process.env.VERSION!; // baked in by Webpack

    public constructor() {
        super();

        // Register the service worker in the background
        this.tryRegisterServiceWorker().catch((e) => console.error("Error registering/updating service worker:", e));
    }

    private async tryRegisterServiceWorker(): Promise<void> {
        if (!("serviceWorker" in navigator)) {
            return; // not available on this platform - don't try to register the service worker
        }

        // sw.js is exported by webpack, sourced from `/src/serviceworker/index.ts`
        const registration = await navigator.serviceWorker.register("sw.js");
        if (!registration) {
            // Registration didn't work for some reason - assume failed and ignore.
            // This typically happens in Jest.
            return;
        }

        navigator.serviceWorker.addEventListener("message", this.onServiceWorkerPostMessage.bind(this));
        await registration.update();
    }

    private onServiceWorkerPostMessage(event: MessageEvent): void {
        try {
            if (event.data?.["type"] === "userinfo" && event.data?.["responseKey"]) {
                const userId = localStorage.getItem("mx_user_id");
                const deviceId = localStorage.getItem("mx_device_id");
                const homeserver = MatrixClientPeg.get()?.getHomeserverUrl();
                event.source!.postMessage({
                    responseKey: event.data["responseKey"],
                    userId,
                    deviceId,
                    homeserver,
                });
            }
        } catch (e) {
            console.error("Error responding to service worker: ", e);
        }
    }

    public getHumanReadableName(): string {
        return "Web Platform"; // no translation required: only used for analytics
    }

    /**
     * Returns true if the platform supports displaying
     * notifications, otherwise false.
     */
    public supportsNotifications(): boolean {
        return Boolean(window.Notification);
    }

    /**
     * Returns true if the application currently has permission
     * to display notifications. Otherwise false.
     */
    public maySendNotifications(): boolean {
        return window.Notification.permission === "granted";
    }

    /**
     * Requests permission to send notifications. Returns
     * a promise that is resolved when the user has responded
     * to the request. The promise has a single string argument
     * that is 'granted' if the user allowed the request or
     * 'denied' otherwise.
     */
    public requestNotificationPermission(): Promise<string> {
        // annoyingly, the latest spec says this returns a
        // promise, but this is only supported in Chrome 46
        // and Firefox 47, so adapt the callback API.
        return new Promise(function (resolve, reject) {
            window.Notification.requestPermission((result) => {
                resolve(result);
            }).catch(reject);
        });
    }

    private async getMostRecentVersion(): Promise<string> {
        const res = await fetch("version", {
            method: "GET",
            cache: "no-cache",
        });

        if (res.ok) {
            const text = await res.text();
            return getNormalizedAppVersion(text.trim());
        }

        return Promise.reject({ status: res.status });
    }

    public getAppVersion(): Promise<string> {
        return Promise.resolve(getNormalizedAppVersion(WebPlatform.VERSION));
    }

    public startUpdater(): void {
        // Poll for an update immediately, and reload the page now if we're out of date
        // already as we've just initialised an old version of the app somehow.
        //
        // Forcibly reloading the page aims to avoid users interacting at all with the old
        // and potentially broken version of the app.
        //
        // Ideally, loading an old copy would be impossible with the
        // cache-control: nocache HTTP header set, but Firefox doesn't always obey it :/
        console.log("startUpdater, current version is " + getNormalizedAppVersion(WebPlatform.VERSION));
        void this.pollForUpdate((version: string, newVersion: string) => {
            const query = parseQs(location);
            if (query.updated) {
                console.log("Update reloaded but still on an old version, stopping");
                // We just reloaded already and are still on the old version!
                // Show the toast rather than reload in a loop.
                showUpdateToast(version, newVersion);
                return;
            }

            // Set updated as a cachebusting query param and reload the page.
            const url = new URL(window.location.href);
            url.searchParams.set("updated", newVersion);
            console.log("Update reloading to " + url.toString());
            window.location.href = url.toString();
        });
        setInterval(() => this.pollForUpdate(showUpdateToast, hideUpdateToast), POKE_RATE_MS);
    }

    public async canSelfUpdate(): Promise<boolean> {
        return true;
    }

    // Exported for tests
    public pollForUpdate = (
        showUpdate: (currentVersion: string, mostRecentVersion: string) => void,
        showNoUpdate?: () => void,
    ): Promise<UpdateStatus> => {
        return this.getMostRecentVersion().then(
            (mostRecentVersion) => {
                const currentVersion = getNormalizedAppVersion(WebPlatform.VERSION);

                if (currentVersion !== mostRecentVersion) {
                    if (this.shouldShowUpdate(mostRecentVersion)) {
                        console.log("Update available to " + mostRecentVersion + ", will notify user");
                        showUpdate(currentVersion, mostRecentVersion);
                    } else {
                        console.log("Update available to " + mostRecentVersion + " but won't be shown");
                    }
                    return { status: UpdateCheckStatus.Ready };
                } else {
                    console.log("No update available, already on " + mostRecentVersion);
                    showNoUpdate?.();
                }

                return { status: UpdateCheckStatus.NotAvailable };
            },
            (err) => {
                logger.error("Failed to poll for update", err);
                return {
                    status: UpdateCheckStatus.Error,
                    detail: err.message || (err.status ? err.status.toString() : "Unknown Error"),
                };
            },
        );
    };

    public startUpdateCheck(): void {
        super.startUpdateCheck();
        void this.pollForUpdate(showUpdateToast, hideUpdateToast).then((updateState) => {
            dis.dispatch<CheckUpdatesPayload>({
                action: Action.CheckUpdates,
                ...updateState,
            });
        });
    }

    public installUpdate(): void {
        window.location.reload();
    }

    public getDefaultDeviceDisplayName(): string {
        // strip query-string and fragment from uri
        const url = new URL(window.location.href);

        // `appName` in the format `develop.element.io/abc/xyz`
        const appName = [
            url.host,
            url.pathname.replace(/\/$/, ""), // Remove trailing slash if present
        ].join("");

        const ua = new UAParser();
        const browserName = ua.getBrowser().name || "unknown browser";
        let osName = ua.getOS().name || "unknown OS";
        // Stylise the value from the parser to match Apple's current branding.
        if (osName === "Mac OS") osName = "macOS";
        return _t("web_default_device_name", {
            appName,
            browserName,
            osName,
        });
    }

    public reload(): void {
        window.location.reload();
    }
}