kratactl: implement output formats

crates/kratactl/src/format.rs

@@ -0,0 +1,51 @@
+use std::collections::HashMap;
+
+use anyhow::Result;
+use prost_reflect::{DynamicMessage, ReflectMessage, Value};
+
+pub fn proto2dynamic(proto: impl ReflectMessage) -> Result<DynamicMessage> {
+    Ok(DynamicMessage::decode(
+        proto.descriptor(),
+        proto.encode_to_vec().as_slice(),
+    )?)
+}
+
+pub fn proto2kv(proto: impl ReflectMessage) -> Result<HashMap<String, String>> {
+    let message = proto2dynamic(proto)?;
+    let mut map = HashMap::new();
+
+    fn crawl(prefix: &str, map: &mut HashMap<String, String>, message: &DynamicMessage) {
+        for (field, value) in message.fields() {
+            let path = if prefix.is_empty() {
+                field.name().to_string()
+            } else {
+                format!("{}.{}", prefix, field.name())
+            };
+            match value {
+                Value::Message(child) => {
+                    crawl(&path, map, child);
+                }
+
+                Value::EnumNumber(number) => {
+                    if let Some(e) = field.kind().as_enum() {
+                        if let Some(value) = e.get_value(*number) {
+                            map.insert(path, value.name().to_string());
+                        }
+                    }
+                }
+
+                Value::String(value) => {
+                    map.insert(path, value.clone());
+                }
+
+                _ => {
+                    map.insert(path, value.to_string());
+                }
+            }
+        }
+    }
+
+    crawl("", &mut map, &message);
+
+    Ok(map)
+}