From 1a5f1bc002a388fff50cf1d50c08b52f0b186bcd Mon Sep 17 00:00:00 2001
From: Anirudh Oppiliappan <anirudh@tangled.sh>
Date: Sat, 23 Aug 2025 13:01:13 +0300
Subject: [PATCH] appview: show error pages

Signed-off-by: Anirudh Oppiliappan <anirudh@tangled.sh>
---
 appview/middleware/middleware.go            | 4 ++--
 appview/pages/pages.go                      | 4 ++++
 appview/pages/templates/errors/knot404.html | 9 +++++++++
 appview/repo/repo.go                        | 9 +++++++++
 4 files changed, 24 insertions(+), 2 deletions(-)
 create mode 100644 appview/pages/templates/errors/knot404.html

diff --git a/appview/middleware/middleware.go b/appview/middleware/middleware.go
index 94b16969..7a32032c 100644
--- a/appview/middleware/middleware.go
+++ b/appview/middleware/middleware.go
@@ -234,7 +234,7 @@ func (mw Middleware) ResolvePull() middlewareFunc {
 			f, err := mw.repoResolver.Resolve(r)
 			if err != nil {
 				log.Println("failed to fully resolve repo", err)
-				http.Error(w, "invalid repo url", http.StatusNotFound)
+				mw.pages.ErrorKnot404(w)
 				return
 			}
 
@@ -283,7 +283,7 @@ func (mw Middleware) GoImport() middlewareFunc {
 			f, err := mw.repoResolver.Resolve(r)
 			if err != nil {
 				log.Println("failed to fully resolve repo", err)
-				http.Error(w, "invalid repo url", http.StatusNotFound)
+				mw.pages.ErrorKnot404(w)
 				return
 			}
 
diff --git a/appview/pages/pages.go b/appview/pages/pages.go
index d0c4d504..97ea6030 100644
--- a/appview/pages/pages.go
+++ b/appview/pages/pages.go
@@ -1272,6 +1272,10 @@ func (p *Pages) Error404(w io.Writer) error {
 	return p.execute("errors/404", w, nil)
 }
 
+func (p *Pages) ErrorKnot404(w io.Writer) error {
+	return p.execute("errors/knot404", w, nil)
+}
+
 func (p *Pages) Error503(w io.Writer) error {
 	return p.execute("errors/503", w, nil)
 }
diff --git a/appview/pages/templates/errors/knot404.html b/appview/pages/templates/errors/knot404.html
new file mode 100644
index 00000000..dcda54b6
--- /dev/null
+++ b/appview/pages/templates/errors/knot404.html
@@ -0,0 +1,9 @@
+{{ define "title" }}404 &middot; tangled{{ end }}
+
+{{ define "content" }}
+    <h1>404 &mdash; repository not found!</h1>
+    <p>
+        The repository you were looking for could not be found.
+        The knot serving the repository may be unavailable.
+    </p>
+{{ end }}
diff --git a/appview/repo/repo.go b/appview/repo/repo.go
index b4a9aa50..48e33eb8 100644
--- a/appview/repo/repo.go
+++ b/appview/repo/repo.go
@@ -125,12 +125,14 @@ func (rp *Repo) RepoLog(w http.ResponseWriter, r *http.Request) {
 
 	repolog, err := us.Log(f.OwnerDid(), f.Name, ref, page)
 	if err != nil {
+		rp.pages.Error503(w)
 		log.Println("failed to reach knotserver", err)
 		return
 	}
 
 	tagResult, err := us.Tags(f.OwnerDid(), f.Name)
 	if err != nil {
+		rp.pages.Error503(w)
 		log.Println("failed to reach knotserver", err)
 		return
 	}
@@ -146,6 +148,7 @@ func (rp *Repo) RepoLog(w http.ResponseWriter, r *http.Request) {
 
 	branchResult, err := us.Branches(f.OwnerDid(), f.Name)
 	if err != nil {
+		rp.pages.Error503(w)
 		log.Println("failed to reach knotserver", err)
 		return
 	}
@@ -312,6 +315,7 @@ func (rp *Repo) RepoCommit(w http.ResponseWriter, r *http.Request) {
 
 	resp, err := http.Get(fmt.Sprintf("%s://%s/%s/%s/commit/%s", protocol, f.Knot, f.OwnerDid(), f.Repo.Name, ref))
 	if err != nil {
+		rp.pages.Error503(w)
 		log.Println("failed to reach knotserver", err)
 		return
 	}
@@ -382,6 +386,7 @@ func (rp *Repo) RepoTree(w http.ResponseWriter, r *http.Request) {
 
 	resp, err := http.Get(fmt.Sprintf("%s://%s/%s/%s/tree/%s/%s", protocol, f.Knot, f.OwnerDid(), f.Repo.Name, ref, treePath))
 	if err != nil {
+		rp.pages.Error503(w)
 		log.Println("failed to reach knotserver", err)
 		return
 	}
@@ -451,6 +456,7 @@ func (rp *Repo) RepoTags(w http.ResponseWriter, r *http.Request) {
 
 	result, err := us.Tags(f.OwnerDid(), f.Name)
 	if err != nil {
+		rp.pages.Error503(w)
 		log.Println("failed to reach knotserver", err)
 		return
 	}
@@ -508,6 +514,7 @@ func (rp *Repo) RepoBranches(w http.ResponseWriter, r *http.Request) {
 
 	result, err := us.Branches(f.OwnerDid(), f.Name)
 	if err != nil {
+		rp.pages.Error503(w)
 		log.Println("failed to reach knotserver", err)
 		return
 	}
@@ -537,6 +544,7 @@ func (rp *Repo) RepoBlob(w http.ResponseWriter, r *http.Request) {
 	}
 	resp, err := http.Get(fmt.Sprintf("%s://%s/%s/%s/blob/%s/%s", protocol, f.Knot, f.OwnerDid(), f.Repo.Name, ref, filePath))
 	if err != nil {
+		rp.pages.Error503(w)
 		log.Println("failed to reach knotserver", err)
 		return
 	}
@@ -1260,6 +1268,7 @@ func (rp *Repo) generalSettings(w http.ResponseWriter, r *http.Request) {
 
 	result, err := us.Branches(f.OwnerDid(), f.Name)
 	if err != nil {
+		rp.pages.Error503(w)
 		log.Println("failed to reach knotserver", err)
 		return
 	}
-- 
2.54.0