refactor(#1456): extract dashboard topology set-parent endpoints into dashboard/topology.rs

hive-c0re/src/dashboard/topology.rs

@@ -0,0 +1,116 @@
+//! Topology (set-parent) endpoints for the dashboard.
+//!
+//! Operator-driven agent reparenting — single (`/api/topology/set-parent`,
+//! form-encoded) and bulk (`/api/topology/set-parent-bulk`, JSON array →
+//! one git commit). Both go through `Coordinator::reparent*_with_notify`,
+//! which wraps `topology::set_parent` with the move-notification messages
+//! and the `ContainerView` rescan.
+
+use axum::{
+    extract::{Form, State},
+    http::StatusCode,
+    response::{IntoResponse, Response},
+};
+use serde::Deserialize;
+
+use super::{AppState, error_response};
+
+/// `POST /api/topology/set-parent` body. `child` is required.
+/// `new_parent` may be:
+/// - absent or empty / whitespace-only → promote to root,
+/// - non-empty → new parent's logical name.
+///
+/// (The CLI surface gates "no parent specified" behind an explicit
+/// `--root` flag for safety; the HTTP surface is permissive
+/// because the dashboard form encodes "no value" as the empty
+/// string for the optional radio-group input.)
+#[derive(Deserialize)]
+pub(super) struct SetParentForm {
+    child: String,
+    new_parent: Option<String>,
+}
+
+/// One entry in a `POST /api/topology/set-parent-bulk` JSON array.
+/// `new_parent`: absent/null/empty-string all mean "promote to root".
+#[derive(Deserialize)]
+pub(super) struct SetParentBulkEntry {
+    child: String,
+    #[serde(default)]
+    new_parent: Option<String>,
+}
+
+/// `POST /api/topology/set-parent` — operator-driven parent move.
+/// Form fields: `child` (required, agent name), `new_parent`
+/// (optional — empty / absent string ⇒ promote to root). Refuses
+/// cycles and unknown agents. The manager is reparentable like any
+/// other agent — its privileges come from the privileged MCP socket,
+/// not its tree position. On success
+/// re-emits container snapshots so the dashboard tree repaints
+/// without a refresh.
+pub(super) async fn post_set_parent(
+    State(state): State<AppState>,
+    Form(form): Form<SetParentForm>,
+) -> Response {
+    let child = form.child.trim().to_owned();
+    if child.is_empty() {
+        return error_response("set-parent: `child` required");
+    }
+    // Empty / whitespace-only `new_parent` ⇒ promote to root. Web
+    // forms submit the empty string for a "no value" radio button,
+    // so this is the ergonomic encoding.
+    let new_parent = form
+        .new_parent
+        .as_deref()
+        .map(str::trim)
+        .filter(|s| !s.is_empty())
+        .map(str::to_owned);
+    // `reparent_with_notify` wraps `topology::set_parent` with the
+    // three notification messages + the ContainerView rescan.
+    // Idempotent same-parent calls skip both the messages and the
+    // disk write per the topology fast-path.
+    match state
+        .coord
+        .reparent_with_notify(&child, new_parent.as_deref())
+        .await
+    {
+        Ok(()) => {
+            tracing::info!(
+                child = %child,
+                new_parent = ?new_parent,
+                "operator: set-parent via dashboard"
+            );
+            (StatusCode::OK, "ok").into_response()
+        }
+        Err(e) => error_response(&format!("set-parent {child} failed: {e}")),
+    }
+}
+
+/// `POST /api/topology/set-parent-bulk` — move multiple agents in a single
+/// request, producing **one** git commit. JSON body: `[{"child":"name",
+/// "new_parent":"target-or-null"}, ...]`. Empty array is a no-op (200 OK).
+/// First validation error aborts the whole batch.
+pub(super) async fn post_set_parent_bulk(
+    State(state): State<AppState>,
+    axum::Json(body): axum::Json<Vec<SetParentBulkEntry>>,
+) -> Response {
+    if body.is_empty() {
+        return (StatusCode::OK, "ok").into_response();
+    }
+    // Collect borrows for the coordinator call.
+    let moves: Vec<(&str, Option<&str>)> = body
+        .iter()
+        .map(|e| {
+            let child: &str = &e.child;
+            let parent: Option<&str> = e.new_parent.as_deref().filter(|s| !s.is_empty());
+            (child, parent)
+        })
+        .collect();
+    match state.coord.reparent_bulk_with_notify(&moves).await {
+        Ok(()) => {
+            let names: Vec<&str> = body.iter().map(|e| e.child.as_str()).collect();
+            tracing::info!(agents = ?names, "operator: set-parent-bulk via dashboard");
+            (StatusCode::OK, "ok").into_response()
+        }
+        Err(e) => error_response(&format!("set-parent-bulk failed: {e}")),
+    }
+}