Implemented reverse resolution for mimetypes

go.mod

@@ -86,6 +86,7 @@ require (
 	github.com/dustin/go-humanize v1.0.0 // indirect
 	github.com/fatih/color v1.13.0 // indirect
 	github.com/fsnotify/fsnotify v1.4.9 // indirect
+	github.com/glpatcern/go-mime v0.0.0-20221026162842-2a8d71ad17a9 // indirect
 	github.com/go-asn1-ber/asn1-ber v1.5.4 // indirect
 	github.com/go-kit/log v0.2.0 // indirect
 	github.com/go-logfmt/logfmt v0.5.1 // indirect

go.sum

@@ -282,6 +282,8 @@ github.com/gdexlab/go-render v1.0.1/go.mod h1:wRi5nW2qfjiGj4mPukH4UV0IknS1cHD4Vg
 github.com/getkin/kin-openapi v0.13.0/go.mod h1:WGRs2ZMM1Q8LR1QBEwUxC6RJEfaBcD0s+pcEVXFuAjw=
 github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
 github.com/gliderlabs/ssh v0.2.2/go.mod h1:U7qILu1NlMHj9FlMhZLlkCdDnU1DBEAqr0aevW3Awn0=
+github.com/glpatcern/go-mime v0.0.0-20221026162842-2a8d71ad17a9 h1:3um08ooi0/lyRmK2eE1XTKmRQHDzPu0IvpCPMljyMZ8=
+github.com/glpatcern/go-mime v0.0.0-20221026162842-2a8d71ad17a9/go.mod h1:EJaddanP+JfU3UkVvn0rYYF3b/gD7eZRejbTHqiQExA=
 github.com/go-acme/lego/v4 v4.4.0/go.mod h1:l3+tFUFZb590dWcqhWZegynUthtaHJbG2fevUpoOOE0=
 github.com/go-asn1-ber/asn1-ber v1.5.4 h1:vXT6d/FNDiELJnLb6hGNa309LMsrCoYFvpwHDF0+Y1A=
 github.com/go-asn1-ber/asn1-ber v1.5.4/go.mod h1:hEBeB/ic+5LoWskz+yKT7vGhhPYkProFKoKdwZRWMe0=

pkg/mime/mime.go

@@ -20,9 +20,10 @@ package mime
 
 import (
 	"path"
+	"strings"
 	"sync"
 
-	gomime "github.com/cubewise-code/go-mime"
+	gomime "github.com/glpatcern/go-mime" // hopefully temporary
 )
 
 const defaultMimeDir = "httpd/unix-directory"
@@ -47,11 +48,15 @@ func Detect(isDir bool, fn string) string {
 	}
 
 	ext := path.Ext(fn)
+	ext = strings.TrimPrefix(ext, ".")
 
 	mimeType := getCustomMime(ext)
 
 	if mimeType == "" {
 		mimeType = gomime.TypeByExtension(ext)
+		if mimeType != "" {
+			mimes.Store(ext, mimeType)
+		}
 	}
 
 	if mimeType == "" {
@@ -61,6 +66,24 @@ func Detect(isDir bool, fn string) string {
 	return mimeType
 }
 
+// GetFileExt performs the inverse resolution from mimetype to file extension
+func GetFileExt(mime string) []string {
+	var found []string
+	// first look in our cache
+	mimes.Range(func(e, m interface{}) bool {
+		if m.(string) == mime {
+			found = append(found, e.(string))
+		}
+		return true
+	})
+	if len(found) > 0 {
+		return found
+	}
+
+	// then use the gomime package
+	return gomime.ExtensionsByType(mime)
+}
+
 func getCustomMime(ext string) string {
 	if m, ok := mimes.Load(ext); ok {
 		return m.(string)