From 5c0038d0282e60572f3f2abd65eb521cb39dff95 Mon Sep 17 00:00:00 2001
From: Levi Neely <141506390+lneely@users.noreply.github.com>
Date: Thu, 27 Nov 2025 13:31:09 +0100
Subject: [PATCH] support compound extensions

---
 internal/disk/callbacks.go | 15 +++++++++++++--
 internal/disk/loader.go    | 36 +++++++++++++++++++++++++++++++++++-
 2 files changed, 48 insertions(+), 3 deletions(-)

diff --git a/internal/disk/callbacks.go b/internal/disk/callbacks.go
index c74baf1..99da015 100644
--- a/internal/disk/callbacks.go
+++ b/internal/disk/callbacks.go
@@ -43,7 +43,7 @@ func HandleUpdateEvent(f *client.Fsys, identifier, denoteDir string) error {
 	if dir == "." {
 		dir = denoteDir
 	}
-	ext := filepath.Ext(path)
+	ext := GetFullExtension(path)
 
 	var fileType metadata.FileType
 	var fm *metadata.FrontMatter
@@ -64,7 +64,18 @@ func HandleUpdateEvent(f *client.Fsys, identifier, denoteDir string) error {
 
 		fm = existing
 		fileType = ftype
-		ext = metadata.GetExtension(fileType)
+
+		// Preserve compound extensions (e.g., .md.gpg)
+		// Replace content extension but keep wrapper layers
+		contentExt := GetContentExtension(path)
+		typeExt := metadata.GetExtension(fileType)
+		if contentExt != ext {
+			// Compound extension: replace content part with type extension
+			ext = strings.Replace(ext, contentExt, typeExt, 1)
+		} else {
+			// Simple extension: use type extension
+			ext = typeExt
+		}
 	} else {
 		// For binary files, build metadata from 9P data
 		fm = &metadata.FrontMatter{
diff --git a/internal/disk/loader.go b/internal/disk/loader.go
index d8119ea..bda0127 100644
--- a/internal/disk/loader.go
+++ b/internal/disk/loader.go
@@ -11,9 +11,43 @@ import (
 	"strings"
 )
 
+// GetFullExtension returns the full extension, including compound extensions.
+// For example: "file.md.gpg" returns ".md.gpg", "file.tar.gz" returns ".tar.gz"
+func GetFullExtension(path string) string {
+	ext := filepath.Ext(path)
+	if ext == "" {
+		return ""
+	}
+
+	// Check if there's another extension before this one
+	pathWithoutExt := strings.TrimSuffix(path, ext)
+	innerExt := filepath.Ext(pathWithoutExt)
+
+	if innerExt != "" {
+		// Compound extension found, return both parts
+		return innerExt + ext
+	}
+
+	return ext
+}
+
+// GetContentExtension returns the content type extension, stripping encryption/compression layers.
+// For example: "file.md.gpg" returns ".md", "file.tar.gz" returns ".tar", "file.md" returns ".md"
+func GetContentExtension(path string) string {
+	fullExt := GetFullExtension(path)
+
+	// For compound extensions, take the first part
+	parts := strings.Split(fullExt, ".")
+	if len(parts) >= 3 { // ["", "md", "gpg"] for ".md.gpg"
+		return "." + parts[1]
+	}
+
+	return fullExt
+}
+
 // SupportsFrontMatter returns true if the file extension supports frontmatter.
 func SupportsFrontMatter(path string) bool {
-	ext := strings.ToLower(filepath.Ext(path))
+	ext := strings.ToLower(GetContentExtension(path))
 	return ext == ".org" || ext == ".md" || ext == ".txt"
 }