[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

2 files changed, 38 insertions, 0 deletions

diff --git a/internal/api/model/account.go b/internal/api/model/account.go
index 7d3fa4b62..af2a394af 100644
--- a/internal/api/model/account.go
+++ b/internal/api/model/account.go
@@ -89,6 +89,8 @@ type Account struct {
 	MuteExpiresAt string `json:"mute_expires_at,omitempty"`
 	// Extra profile information. Shown only if the requester owns the account being requested.
 	Source *Source `json:"source,omitempty"`
+	// Filename of user-selected CSS theme to include when rendering this account's profile or statuses. Eg., `blurple-light.css`.
+	Theme string `json:"theme,omitempty"`
 	// CustomCSS to include when rendering this account's profile or statuses.
 	CustomCSS string `json:"custom_css,omitempty"`
 	// Account has enabled RSS feed.
@@ -162,7 +164,11 @@ type UpdateCredentialsRequest struct {
 	FieldsAttributes *[]UpdateField `form:"fields_attributes" json:"-"`
 	// Profile metadata names and values, parsed from JSON.
 	JSONFieldsAttributes *map[string]UpdateField `form:"-" json:"fields_attributes"`
+	// Theme file name to be used when rendering this account's profile or statuses.
+	// Use empty string to unset.
+	Theme *string `form:"theme" json:"theme"`
 	// Custom CSS to be included when rendering this account's profile or statuses.
+	// Use empty string to unset.
 	CustomCSS *string `form:"custom_css" json:"custom_css"`
 	// Enable RSS feed of public toots for this account at /@[username]/feed.rss
 	EnableRSS *bool `form:"enable_rss" json:"enable_rss"`
diff --git a/internal/api/model/theme.go b/internal/api/model/theme.go
new file mode 100644
index 000000000..b98e7395a
--- /dev/null
+++ b/internal/api/model/theme.go
@@ -0,0 +1,32 @@
+// 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/>.
+
+package model
+
+// Theme represents one user-selectable preset CSS theme.
+//
+// swagger:model theme
+type Theme struct {
+	// User-facing title of this theme.
+	Title string `json:"title"`
+
+	// User-facing description of this theme.
+	Description string `json:"description"`
+
+	// FileName of this theme in the themes directory.
+	FileName string `json:"file_name"`
+}