[feature] User-selectable preset CSS themes for accounts (#2777)

* [feature] User-selectable preset themes

* docs, more theme stuff

* lint, tests

* fix css name

* correct some little issues

* add another theme

* fix poll background

* okay last theme i swear

* make retrieval of apimodel themes more conventional

* preallocate stylesheet slices

4 files changed, 73 insertions, 5 deletions

diff --git a/web/source/settings/lib/query/user/index.ts b/web/source/settings/lib/query/user/index.ts
index 8cf64197b..8c4e5215b 100644
--- a/web/source/settings/lib/query/user/index.ts
+++ b/web/source/settings/lib/query/user/index.ts
@@ -23,6 +23,7 @@ import type {
 	MoveAccountFormData,
 	UpdateAliasesFormData
 } from "../../types/migration";
+import type { Theme } from "../../types/theme";
 
 const extended = gtsApi.injectEndpoints({
 	endpoints: (build) => ({
@@ -66,6 +67,11 @@ const extended = gtsApi.injectEndpoints({
 				url: `/api/v1/accounts/move`,
 				body: data
 			})
+		}),
+		accountThemes: build.query<Theme[], void>({
+			query: () => ({
+				url: `/api/v1/accounts/themes`
+			})
 		})
 	})
 });
@@ -75,4 +81,5 @@ export const {
 	usePasswordChangeMutation,
 	useAliasAccountMutation,
 	useMoveAccountMutation,
+	useAccountThemesQuery,
 } = extended;
diff --git a/web/source/settings/lib/types/theme.ts b/web/source/settings/lib/types/theme.ts
new file mode 100644
index 000000000..e605192f8
--- /dev/null
+++ b/web/source/settings/lib/types/theme.ts
@@ -0,0 +1,24 @@
+/*
+	GoToSocial
+	Copyright (C) GoToSocial Authors admin@gotosocial.org
+	SPDX-License-Identifier: AGPL-3.0-or-later
+
+	This program is free software: you can redistribute it and/or modify
+	it under the terms of the GNU Affero General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU Affero General Public License for more details.
+
+	You should have received a copy of the GNU Affero General Public License
+	along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+export interface Theme {
+	title: string;
+	description: string;
+	file_name: string;
+}
diff --git a/web/source/settings/style.css b/web/source/settings/style.css
index 501e9dbef..372031203 100644
--- a/web/source/settings/style.css
+++ b/web/source/settings/style.css
@@ -439,7 +439,7 @@ section.with-sidebar > div, section.with-sidebar > form {
 		display: grid;
 		max-width: 60rem;
 		grid-template-columns: 70% 30%;
-		grid-template-rows: 100%;
+		grid-template-rows: auto;
 		gap: 1rem;
 
 		.files {
@@ -465,6 +465,12 @@ section.with-sidebar > div, section.with-sidebar > form {
 			gap: 0.5rem;
 		}
 	}
+
+	.theme, .form-field.radio {
+		display: flex;
+		flex-direction: column;
+		gap: 0.5rem;
+	}
 }
 
 .migration-details {
diff --git a/web/source/settings/user/profile.tsx b/web/source/settings/user/profile.tsx
index a03d4d247..cd4b17227 100644
--- a/web/source/settings/user/profile.tsx
+++ b/web/source/settings/user/profile.tsx
@@ -23,7 +23,8 @@ import {
 	useTextInput,
 	useFileInput,
 	useBoolInput,
-	useFieldArrayInput
+	useFieldArrayInput,
+	useRadioInput
 } from "../lib/form";
 
 import useFormSubmit from "../lib/form/submit";
@@ -33,14 +34,15 @@ import {
 	TextInput,
 	TextArea,
 	FileInput,
-	Checkbox
+	Checkbox,
+	RadioGroup
 } from "../components/form/inputs";
 
 import FormWithData from "../lib/form/form-with-data";
 import FakeProfile from "../components/fake-profile";
 import MutationButton from "../components/form/mutation-button";
 
-import { useInstanceV1Query } from "../lib/query";
+import { useAccountThemesQuery, useInstanceV1Query } from "../lib/query";
 import { useUpdateCredentialsMutation } from "../lib/query/user";
 import { useVerifyCredentialsQuery } from "../lib/query/oauth";
 
@@ -64,6 +66,7 @@ function UserProfileForm({ data: profile }) {
 		- file header
 		- bool enable_rss
 		- string custom_css (if enabled)
+		- string theme
 	*/
 
 	const { data: instance } = useInstanceV1Query();
@@ -73,13 +76,24 @@ function UserProfileForm({ data: profile }) {
 			maxPinnedFields: instance?.configuration?.accounts?.max_profile_fields ?? 6
 		};
 	}, [instance]);
+	
+	// Parse out available theme options into nice format.
+	const { data: themes } = useAccountThemesQuery();
+	let themeOptions = { "": "Default" };
+	themes?.forEach((theme) => {
+		let key = theme.file_name;
+		let value = theme.title;
+		if (theme.description) {
+			value += " - " + theme.description;
+		}
+		themeOptions[key] = value;
+	});
 
 	const form = {
 		avatar: useFileInput("avatar", { withPreview: true }),
 		header: useFileInput("header", { withPreview: true }),
 		displayName: useTextInput("display_name", { source: profile }),
 		note: useTextInput("note", { source: profile, valueSelector: (p) => p.source?.note }),
-		customCSS: useTextInput("custom_css", { source: profile, nosubmit: !instanceConfig.allowCustomCSS }),
 		bot: useBoolInput("bot", { source: profile }),
 		locked: useBoolInput("locked", { source: profile }),
 		discoverable: useBoolInput("discoverable", { source: profile}),
@@ -88,6 +102,11 @@ function UserProfileForm({ data: profile }) {
 			defaultValue: profile?.source?.fields,
 			length: instanceConfig.maxPinnedFields
 		}),
+		customCSS: useTextInput("custom_css", { source: profile, nosubmit: !instanceConfig.allowCustomCSS }),
+		theme: useRadioInput("theme", {
+			source: profile,
+			options: themeOptions,
+		}),
 	};
 
 	const [submitForm, result] = useFormSubmit(form, useUpdateCredentialsMutation(), {
@@ -125,6 +144,18 @@ function UserProfileForm({ data: profile }) {
 						/>
 					</div>
 				</div>
+
+				<div className="theme">
+					<div>
+						<b id="theme-label">Theme</b>
+						<br/>
+						<span>After choosing theme and saving, <a href={profile.url} target="_blank">open your profile</a> and refresh to see changes.</span>
+					</div>
+					<RadioGroup
+						aria-labelledby="theme-label"
+						field={form.theme}
+					/>
+				</div>
 			</div>
 
 			<div className="form-section-docs">