MM-49393 Begin splitting up utils.tsx (#22983)

* Add selectors/urls to Channels

* Create utils/notification_sounds in Channels

* Move Utils.isLinux to UserAgent.isLinux

* Remove Utils.isMac in favour of UserAgent.isMac

* Move cmdOrCtrlPressed and isKeyPressed into new utils/keyboard

* Remove eslint-disable for max-lines in utils.tsx

webapp/channels/src/selectors/urls.ts

@@ -0,0 +1,53 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+import {Post} from '@mattermost/types/posts';
+import {Channel} from '@mattermost/types/channels';
+import {Team} from '@mattermost/types/teams';
+
+import {getRedirectChannelNameForTeam} from 'mattermost-redux/selectors/entities/channels';
+import {
+    getCurrentRelativeTeamUrl,
+    getCurrentTeam,
+    getCurrentTeamId,
+    getTeam,
+} from 'mattermost-redux/selectors/entities/teams';
+
+import {GlobalState} from 'types/store';
+
+import Constants from 'utils/constants';
+
+function getTeamRelativeUrl(team: Team | undefined) {
+    if (!team) {
+        return '';
+    }
+
+    return '/' + team.name;
+}
+
+export function getPermalinkURL(state: GlobalState, teamId: Team['id'], postId: Post['id']): string {
+    let team = getTeam(state, teamId);
+    if (!team) {
+        team = getCurrentTeam(state);
+    }
+    return `${getTeamRelativeUrl(team)}/pl/${postId}`;
+}
+
+export function getChannelURL(state: GlobalState, channel: Channel, teamId: string): string {
+    let notificationURL;
+    if (channel && (channel.type === Constants.DM_CHANNEL || channel.type === Constants.GM_CHANNEL)) {
+        notificationURL = getCurrentRelativeTeamUrl(state) + '/channels/' + channel.name;
+    } else if (channel) {
+        const team = getTeam(state, teamId);
+        notificationURL = getTeamRelativeUrl(team) + '/channels/' + channel.name;
+    } else if (teamId) {
+        const team = getTeam(state, teamId);
+        const redirectChannel = getRedirectChannelNameForTeam(state, teamId);
+        notificationURL = getTeamRelativeUrl(team) + `/channels/${redirectChannel}`;
+    } else {
+        const currentTeamId = getCurrentTeamId(state);
+        const redirectChannel = getRedirectChannelNameForTeam(state, currentTeamId);
+        notificationURL = getCurrentRelativeTeamUrl(state) + `/channels/${redirectChannel}`;
+    }
+    return notificationURL;
+}