Add middleware for checking the requested mime type

web/public/middleware/mimeTypeCheck.go

@@ -0,0 +1,36 @@
+package webmiddleware
+
+import (
+	"net/http"
+	"strings"
+
+	webutils "git.mstar.dev/mstar/goutils/http"
+	"git.mstar.dev/mstar/goutils/other"
+)
+
+func BuildMimetypeCheck(acceptedMimetypes []string) webutils.HandlerBuilder {
+	return func(h http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			acceptHeader := r.Header.Get("Accept")
+			for _, couldBe := range acceptedMimetypes {
+				if strings.Contains(acceptHeader, couldBe) {
+					h.ServeHTTP(w, r)
+					return
+				}
+			}
+			// Requested mimtype not in list of accepted ones, failing request with note
+			webutils.ProblemDetails(
+				w,
+				http.StatusUnsupportedMediaType,
+				"/errors/bad-accept-mime-type",
+				"unsupported mime type",
+				other.IntoPointer(
+					"The requested mime type is not supported. Please check extras for a list of supported mime types",
+				),
+				map[string]any{
+					"supported-mime-types": acceptedMimetypes,
+				},
+			)
+		})
+	}
+}