gotosocial/internal/web/customcss.go

/*
   GoToSocial
   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org

   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 web

import (
	"errors"
	"net/http"
	"strings"

	"github.com/gin-gonic/gin"
	"github.com/superseriousbusiness/gotosocial/internal/api"
	"github.com/superseriousbusiness/gotosocial/internal/config"
	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
)

const textCSSUTF8 = string(api.TextCSS + "; charset=utf-8")

func (m *Module) customCSSGETHandler(c *gin.Context) {
	if !config.GetAccountsAllowCustomCSS() {
		err := errors.New("accounts-allow-custom-css is not enabled on this instance")
		api.ErrorHandler(c, gtserror.NewErrorNotFound(err), m.processor.InstanceGet)
		return
	}

	if _, err := api.NegotiateAccept(c, api.TextCSS); err != nil {
		api.ErrorHandler(c, gtserror.NewErrorNotAcceptable(err, err.Error()), m.processor.InstanceGet)
		return
	}

	// usernames on our instance will always be lowercase
	username := strings.ToLower(c.Param(usernameKey))
	if username == "" {
		err := errors.New("no account username specified")
		api.ErrorHandler(c, gtserror.NewErrorBadRequest(err, err.Error()), m.processor.InstanceGet)
		return
	}

	customCSS, errWithCode := m.processor.AccountGetCustomCSSForUsername(c.Request.Context(), username)
	if errWithCode != nil {
		api.ErrorHandler(c, errWithCode, m.processor.InstanceGet)
		return
	}

	c.Header(cacheControlHeader, cacheControlNoCache)
	c.Data(http.StatusOK, textCSSUTF8, []byte(customCSS))
}