[feature/frontend] Add login button to index page which reiterates info about clients (#3377)

* Add login button to index page which reiterates info about clients

* bit of CSS fiddling, move apps from front page to login info

* fix indentation

---------

Co-authored-by: tobi <tobi.smethurst@protonmail.com>

internal/web/index.go

@@ -60,7 +60,14 @@ func (m *Module) indexHandler(c *gin.Context) {
 		Instance:    instance,
 		OGMeta:      apiutil.OGBase(instance),
 		Stylesheets: []string{cssAbout, cssIndex},
-		Extra:       map[string]any{"showStrap": true},
+		Extra: map[string]any{
+			// Render "home to x
+			// users [etc]" strap.
+			"showStrap": true,
+			// Show "log in" button
+			// in top-right corner.
+			"showLoginButton": true,
+		},
 	}
 
 	apiutil.TemplateWebPage(c, page)

internal/web/login-info.go

@@ -0,0 +1,60 @@
+// 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"
+
+	"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/gtserror"
+)
+
+const (
+	loginPath = "/login"
+)
+
+func (m *Module) loginGETHandler(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
+	}
+
+	page := apiutil.WebPage{
+		Template:    "login_info.tmpl",
+		Instance:    instance,
+		OGMeta:      apiutil.OGBase(instance),
+		Stylesheets: []string{cssAbout, cssLoginInfo},
+	}
+
+	apiutil.TemplateWebPage(c, page)
+}

internal/web/web.go

@@ -59,14 +59,15 @@ const (
 	eTagHeader            = "ETag"              // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag
 	lastModifiedHeader    = "Last-Modified"     // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Last-Modified
 
-	cssFA       = assetsPathPrefix + "/Fork-Awesome/css/fork-awesome.min.css"
-	cssAbout    = distPathPrefix + "/about.css"
-	cssIndex    = distPathPrefix + "/index.css"
-	cssStatus   = distPathPrefix + "/status.css"
-	cssThread   = distPathPrefix + "/thread.css"
-	cssProfile  = distPathPrefix + "/profile.css"
-	cssSettings = distPathPrefix + "/settings-style.css"
-	cssTag      = distPathPrefix + "/tag.css"
+	cssFA        = assetsPathPrefix + "/Fork-Awesome/css/fork-awesome.min.css"
+	cssAbout     = distPathPrefix + "/about.css"
+	cssIndex     = distPathPrefix + "/index.css"
+	cssLoginInfo = distPathPrefix + "/login-info.css"
+	cssStatus    = distPathPrefix + "/status.css"
+	cssThread    = distPathPrefix + "/thread.css"
+	cssProfile   = distPathPrefix + "/profile.css"
+	cssSettings  = distPathPrefix + "/settings-style.css"
+	cssTag       = distPathPrefix + "/tag.css"
 
 	jsFrontend = distPathPrefix + "/frontend.js" // Progressive enhancement frontend JS.
 	jsSettings = distPathPrefix + "/settings.js" // Settings panel React application.
@@ -121,6 +122,7 @@ func (m *Module) Route(r *router.Router, mi ...gin.HandlerFunc) {
 	r.AttachHandler(http.MethodPost, confirmEmailPath, m.confirmEmailPOSTHandler)
 	r.AttachHandler(http.MethodGet, robotsPath, m.robotsGETHandler)
 	r.AttachHandler(http.MethodGet, aboutPath, m.aboutGETHandler)
+	r.AttachHandler(http.MethodGet, loginPath, m.loginGETHandler)
 	r.AttachHandler(http.MethodGet, domainBlockListPath, m.domainBlockListGETHandler)
 	r.AttachHandler(http.MethodGet, tagsPath, m.tagGETHandler)
 	r.AttachHandler(http.MethodGet, signupPath, m.signupGETHandler)