From 6fe6c856cd3f8b21e4421d963139620ccd81e61b Mon Sep 17 00:00:00 2001
From: "Alexander \"Arav\" Andreev" <me@arav.su>
Date: Sat, 12 Aug 2023 23:51:26 +0400
Subject: [PATCH] Show Go back on error page, need to pass a referer URL for
 it.

---
 cmd/dwelling-home/main.go               |  4 ++--
 internal/http/api_guestbook_handlers.go |  9 ++++++---
 internal/http/api_mindflow_handlers.go  |  2 +-
 internal/http/web_handlers.go           | 10 +++++-----
 4 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/cmd/dwelling-home/main.go b/cmd/dwelling-home/main.go
index 60a87b6..dcd2baa 100644
--- a/cmd/dwelling-home/main.go
+++ b/cmd/dwelling-home/main.go
@@ -74,8 +74,8 @@ func main() {
 
 	r := httpr.New()
 
-	r.NotFoundHandler = func(w http.ResponseWriter, _ *http.Request) {
-		web.ErrorXXX("/ Not Found", "", "", http.StatusNotFound, w)
+	r.NotFoundHandler = func(w http.ResponseWriter, r *http.Request) {
+		web.ErrorXXX("/ Not Found", "", "", r.Referer(), http.StatusNotFound, w)
 	}
 
 	r.ServeStatic("/assets/*filepath", web.Assets())
diff --git a/internal/http/api_guestbook_handlers.go b/internal/http/api_guestbook_handlers.go
index 1461594..c49c2c9 100644
--- a/internal/http/api_guestbook_handlers.go
+++ b/internal/http/api_guestbook_handlers.go
@@ -29,7 +29,8 @@ func (h *GuestbookApiHandlers) New(w http.ResponseWriter, r *http.Request) {
 		r.ParseForm()
 
 		if !inmemdb.Solve(captcha.ID(r.FormValue("captcha_id")), captcha.Answer(r.FormValue("captcha_answer"))) {
-			Error(w, http.StatusForbidden, "Wrong answer given.", "Here's your message:"+r.FormValue("message"))
+			Error(w, http.StatusForbidden, "Wrong answer given.",
+				"Here's your message:"+r.FormValue("message"), r.Referer())
 			return
 		}
 
@@ -42,13 +43,15 @@ func (h *GuestbookApiHandlers) New(w http.ResponseWriter, r *http.Request) {
 		entry, err = justguestbook.NewEntry(r.FormValue("name"), message,
 			r.FormValue("website"), r.FormValue("hide_website") != "")
 		if err != nil {
-			Error(w, http.StatusInternalServerError, err.Error(), "Here's your message:"+r.FormValue("message"))
+			Error(w, http.StatusInternalServerError, err.Error(),
+				"Here's your message:"+r.FormValue("message"), r.Referer())
 			return
 		}
 	}
 
 	if err = h.db.NewEntry(entry); err != nil {
-		Error(w, http.StatusInternalServerError, err.Error(), "Here's your message:"+r.FormValue("message"))
+		Error(w, http.StatusInternalServerError, err.Error(),
+			"Here's your message:"+r.FormValue("message"), r.Referer())
 		return
 	}
 
diff --git a/internal/http/api_mindflow_handlers.go b/internal/http/api_mindflow_handlers.go
index b44b45d..23342f8 100644
--- a/internal/http/api_mindflow_handlers.go
+++ b/internal/http/api_mindflow_handlers.go
@@ -51,7 +51,7 @@ func (h *MindflowApiHandlers) NewPost(w http.ResponseWriter, r *http.Request) {
 
 	if err = h.db.NewPost(post); err != nil {
 		msg := strings.Join([]string{"Title:", r.FormValue("title"), "| Body:", r.FormValue("body")}, " ")
-		Error(w, http.StatusInternalServerError, err.Error(), msg)
+		Error(w, http.StatusInternalServerError, err.Error(), msg, r.Referer())
 		return
 	}
 
diff --git a/internal/http/web_handlers.go b/internal/http/web_handlers.go
index 1e5ffdb..d8be2f0 100644
--- a/internal/http/web_handlers.go
+++ b/internal/http/web_handlers.go
@@ -70,13 +70,13 @@ func (h *Handlers) Mindflow(w http.ResponseWriter, r *http.Request) {
 func (h *Handlers) MindflowAdmin(w http.ResponseWriter, r *http.Request) {
 	posts, err := h.mindflowDB.Posts()
 	if err != nil {
-		Error(w, http.StatusInternalServerError, err.Error(), "failed to load posts")
+		Error(w, http.StatusInternalServerError, err.Error(), "failed to load posts", r.Referer())
 		return
 	}
 
 	categories, err := h.mindflowDB.Categories()
 	if err != nil {
-		Error(w, http.StatusInternalServerError, err.Error(), "failed to load categories")
+		Error(w, http.StatusInternalServerError, err.Error(), "failed to load categories", r.Referer())
 		return
 	}
 
@@ -153,7 +153,7 @@ func (h *Handlers) GuestbookAdmin(w http.ResponseWriter, r *http.Request) {
 	entriesCount, _ := h.guestbookDB.Count()
 	entries, err := h.guestbookDB.Entries(1, entriesCount)
 	if err != nil {
-		Error(w, http.StatusInternalServerError, err.Error(), "cannot load gb")
+		Error(w, http.StatusInternalServerError, err.Error(), "cannot load gb", r.Referer())
 		return
 	}
 	for _, entry := range entries {
@@ -187,8 +187,8 @@ func SitemapXml(w http.ResponseWriter, r *http.Request) {
 	w.Write(data)
 }
 
-func Error(w http.ResponseWriter, code int, reason, message string) {
-	web.ErrorXXX("/ "+http.StatusText(code), reason, message, code, w)
+func Error(w http.ResponseWriter, code int, reason, message, referer string) {
+	web.ErrorXXX("/ "+http.StatusText(code), reason, message, referer, code, w)
 }
 
 func cleanupNewlines(text string) (out string) {