Add timezone to user profile (#20)

* [create-pull-request] automated change (#12966)

Co-authored-by: github-merge-queue <github-merge-queue@users.noreply.github.com>

* Add timezone to right panel profile.

* Add setting to publish timezone

* Add string for timezone publish

* Automatically update timezone when setting changes.

* Refactor to using a hook

And automatically refresh the timezone every minute.

* Check for feature support for extended profiles.

* lint

* Add timezone

* Remove unintentional changes

* Use browser default timezone.

* lint

* tweaks

* Set timezone publish at the device level to prevent all devices writing to the timezone field.

* Update hook to use external client.

* Add test for user timezone.

* Update snapshot for preferences tab.

* Hide timezone info if not provided.

* Stablize test

* Fix date test types.

* prettier

* Add timezone tests

* Add test for invalid timezone.

* Update screenshot

* Remove check for profile.

---------

Co-authored-by: ElementRobot <releases@riot.im>
Co-authored-by: github-merge-queue <github-merge-queue@users.noreply.github.com>

src/hooks/useUserTimezone.ts

@@ -0,0 +1,106 @@
+/*
+Copyright 2024 New Vector 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 { useEffect, useState } from "react";
+import { MatrixClient, MatrixError } from "matrix-js-sdk/src/matrix";
+
+/**
+ * Fetch a user's delclared timezone through their profile, and return
+ * a friendly string of the current time for that user. This will keep
+ * in sync with the current time, and will be refreshed once a minute.
+ *
+ * @param cli The Matrix Client instance.
+ * @param userId The userID to fetch the timezone for.
+ * @returns A timezone name and friendly string for the user's timezone, or
+ *          null if the user has no timezone or the timezone was not recognised
+ *          by the browser.
+ */
+export const useUserTimezone = (cli: MatrixClient, userId: string): { timezone: string; friendly: string } | null => {
+    const [timezone, setTimezone] = useState<string>();
+    const [updateInterval, setUpdateInterval] = useState<number>();
+    const [friendly, setFriendly] = useState<string>();
+    const [supported, setSupported] = useState<boolean>();
+
+    useEffect(() => {
+        if (!cli || supported !== undefined) {
+            return;
+        }
+        cli.doesServerSupportExtendedProfiles()
+            .then(setSupported)
+            .catch((ex) => {
+                console.warn("Unable to determine if extended profiles are supported", ex);
+            });
+    }, [supported, cli]);
+
+    useEffect(() => {
+        return () => {
+            if (updateInterval) {
+                clearInterval(updateInterval);
+            }
+        };
+    }, [updateInterval]);
+
+    useEffect(() => {
+        if (supported !== true) {
+            return;
+        }
+        (async () => {
+            console.log("Trying to fetch TZ");
+            try {
+                const tz = await cli.getExtendedProfileProperty(userId, "us.cloke.msc4175.tz");
+                if (typeof tz !== "string") {
+                    // Err, definitely not a tz.
+                    throw Error("Timezone value was not a string");
+                }
+                // This will validate the timezone for us.
+                // eslint-disable-next-line new-cap
+                Intl.DateTimeFormat(undefined, { timeZone: tz });
+
+                const updateTime = (): void => {
+                    const currentTime = new Date();
+                    const friendly = currentTime.toLocaleString(undefined, {
+                        timeZone: tz,
+                        hour12: true,
+                        hour: "2-digit",
+                        minute: "2-digit",
+                        timeZoneName: "shortOffset",
+                    });
+                    setTimezone(tz);
+                    setFriendly(friendly);
+                    setUpdateInterval(setTimeout(updateTime, (60 - currentTime.getSeconds()) * 1000));
+                };
+                updateTime();
+            } catch (ex) {
+                setTimezone(undefined);
+                setFriendly(undefined);
+                setUpdateInterval(undefined);
+                if (ex instanceof MatrixError && ex.errcode === "M_NOT_FOUND") {
+                    // No timezone set, ignore.
+                    return;
+                }
+                console.error("Could not render current timezone for user", ex);
+            }
+        })();
+    }, [supported, userId, cli]);
+
+    if (!timezone || !friendly) {
+        return null;
+    }
+
+    return {
+        friendly,
+        timezone,
+    };
+};