From a8705c5df37a7599181a8da2dbcb46914c106a09 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lilian=20J=C3=B3nsd=C3=B3ttir?=
 <lilian.jonsdottir@gmail.com>
Date: Sat, 27 Jan 2024 16:28:03 -0800
Subject: [PATCH] handle robots.txt

---
 cmd/web/routes.go             |  3 ++-
 internal/handlers/handlers.go | 13 +++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/cmd/web/routes.go b/cmd/web/routes.go
index 581fe08..1f63aff 100644
--- a/cmd/web/routes.go
+++ b/cmd/web/routes.go
@@ -29,8 +29,9 @@ func routes(app *config.AppConfig) http.Handler {
 		mux.Get(handler.Handles, handler.Handler)
 	}
 
-	// Setup home handler
+	// Setup extra handlers
 	mux.Get("/", handlers.HomeHandler)
+	mux.Get("/robots.txt", handlers.RobotHandler)
 
 	return mux
 }
diff --git a/internal/handlers/handlers.go b/internal/handlers/handlers.go
index 6f655f0..4dfe824 100644
--- a/internal/handlers/handlers.go
+++ b/internal/handlers/handlers.go
@@ -75,6 +75,19 @@ func HomeHandler(writer http.ResponseWriter, request *http.Request) {
 	render.RenderTemplateWithData(writer, "home.page.tmpl", &d)
 }
 
+// RobotHandler creates a handler for robots.txt out of existing Handlers
+func RobotHandler(writer http.ResponseWriter, request *http.Request) {
+	robots := fmt.Sprintf("User-agent: %s\nAllow: /\n", request.UserAgent())
+
+	for _, handler := range Handlers {
+		robots += fmt.Sprintf("Allow: %s\n", handler.Handles)
+	}
+
+	robots += "Disallow: /*\n"
+
+	fmt.Fprint(writer, robots)
+}
+
 // makeBasicHandler returns a simple handler that renders a template from `name`.page.tmpl
 func makeBasicHandler(name string) func(writer http.ResponseWriter, request *http.Request) {
 	return func(writer http.ResponseWriter, request *http.Request) {