[chore] Refactor HTML templates and CSS (#2480)

* [chore] Refactor HTML templates and CSS

* eslint

* ignore "Local"

* rss tests

* fiddle with OG just a tiny bit

* dick around with polls a bit more so SR stops saying "clickable"

* remove break

* oh lord

* don't lazy load avatar

* fix ogmeta tests

* clean up some cruft

* catch remaining calls to c.HTML

* fix error rendering + stack overflow in tag

* allow templating attributes

* fix indent

* set aria-hidden on status complementary content, since it's already present in the label anyway

* tidy up templating calls a little

* try to make styling a bit more consistent + readable

* fix up some remaining CSS issues

* fix up reports

1 files changed, 67 insertions, 0 deletions

diff --git a/internal/web/index.go b/internal/web/index.go
new file mode 100644
index 000000000..25960cf7f
--- /dev/null
+++ b/internal/web/index.go
@@ -0,0 +1,67 @@
+// 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 web
+
+import (
+	"context"
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
+	apiutil "github.com/superseriousbusiness/gotosocial/internal/api/util"
+	"github.com/superseriousbusiness/gotosocial/internal/config"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+)
+
+func (m *Module) indexHandler(c *gin.Context) {
+	instance, errWithCode := m.processor.InstanceGetV1(c.Request.Context())
+	if errWithCode != nil {
+		apiutil.WebErrorHandler(c, errWithCode, m.processor.InstanceGetV1)
+		return
+	}
+
+	// Return instance we already got from the db,
+	// don't try to fetch it again when erroring.
+	instanceGet := func(ctx context.Context) (*apimodel.InstanceV1, gtserror.WithCode) {
+		return instance, nil
+	}
+
+	// We only serve text/html at this endpoint.
+	if _, err := apiutil.NegotiateAccept(c, apiutil.TextHTML); err != nil {
+		apiutil.WebErrorHandler(c, gtserror.NewErrorNotAcceptable(err, err.Error()), instanceGet)
+		return
+	}
+
+	// If a landingPageUser is set in the config, redirect to
+	// that user's profile instead of rendering landing/index page.
+	if landingPageUser := config.GetLandingPageUser(); landingPageUser != "" {
+		c.Redirect(http.StatusFound, "/@"+strings.ToLower(landingPageUser))
+		return
+	}
+
+	page := apiutil.WebPage{
+		Template:    "index.tmpl",
+		Instance:    instance,
+		OGMeta:      apiutil.OGBase(instance),
+		Stylesheets: []string{cssAbout, cssIndex},
+		Extra:       map[string]any{"showStrap": true},
+	}
+
+	apiutil.TemplateWebPage(c, page)
+}