web & server: improved debug printing of unhandled mime types

server/src/graphql.rs

@@ -246,7 +246,10 @@ impl QueryRoot {
                 "text/plain" => Body::PlainText(PlainText { text: body }),
                 "text/html" => Body::Html(Html { html: body }),
                 _ => {
-                    let msg = format!("Unhandled body content type: {}", m.ctype.mimetype);
+                    let msg = format!(
+                        "Unhandled body content type:\n{}",
+                        render_content_type_tree(&m)
+                    );
                     warn!("{}", msg);
                     Body::UnhandledContentType(UnhandledContentType { text: msg })
                 }
@@ -273,6 +276,31 @@ impl QueryRoot {
     }
 }
 
+fn render_content_type_tree(m: &ParsedMail) -> String {
+    const WIDTH: usize = 4;
+    fn render_rec(m: &ParsedMail, depth: usize) -> String {
+        let mut parts = Vec::new();
+        let msg = format!("{} {}", "-".repeat(depth * WIDTH), m.ctype.mimetype);
+        println!("{msg}",);
+        parts.push(msg);
+        if !m.ctype.charset.is_empty() {
+            parts.push(format!(
+                "{} Character Set: {}",
+                " ".repeat(depth * WIDTH),
+                m.ctype.charset
+            ));
+        }
+        for (k, v) in m.ctype.params.iter() {
+            parts.push(format!("{} {k}: {v}", " ".repeat(depth * WIDTH),));
+        }
+        for sp in &m.subparts {
+            parts.push(render_rec(sp, depth + 1))
+        }
+        parts.join("\n")
+    }
+    render_rec(m, 1)
+}
+
 pub type GraphqlSchema = Schema<QueryRoot, EmptyMutation, EmptySubscription>;
 
 fn email_addresses(path: &str, m: &ParsedMail, header_name: &str) -> Result<Vec<Email>, Error> {