feat: Add rename calls and slug preview to the HQ client

adminsite/lib/api.ts

@@ -129,6 +129,7 @@ export interface Instance {
     status: InstanceStatus;
     current_license?: string;
     relink_count: number;
+    renamed_at?: string;
     inject_failed_at?: string | null;
     notices_sent?: string[];
     created_at: string;
@@ -288,6 +289,14 @@ export interface StaffInstanceResponse {
     injection: { applicable: boolean; state?: InjectionState; failed_at?: string | null };
 }
 
+export interface RenameResult {
+    instance_id: string;
+    name: string;
+    slug: string;
+    /** Empty when APP_LOGIN_URL is unset on the server. */
+    login_url?: string;
+}
+
 // --- calls ---------------------------------------------------------------
 
 export const api = {
@@ -306,6 +315,8 @@ export const api = {
         post<Instance>("/api/instances/link", { instance_id, name }),
     createInstance: (name: string) => post<Instance>("/api/instances", { name }),
     renewInstance: (id: string) => post<License>(`/api/instances/${id}/renew`, {}),
+    renameInstance: (id: string, name: string) =>
+        put<RenameResult>(`/api/instances/${id}/name`, { name }),
     // Self-hosted Free: issue the licence on an already-linked instance.
     claimFree: (id: string) => post<License>(`/api/instances/${id}/claim-free`, {}),
     relink: (id: string, instance_id: string) =>
@@ -367,6 +378,8 @@ export const api = {
             post<License>(`/api/staff/instances/${id}/issue`, payload),
         relink: (id: string, instance_id: string) =>
             post<License>(`/api/staff/instances/${id}/relink`, { instance_id }),
+        renameInstance: (id: string, name: string) =>
+            put<RenameResult>(`/api/staff/instances/${id}/name`, { name }),
         licenses: (params?: Record<string, string>) =>
             req<License[]>(`/api/staff/licenses${params ? `?${new URLSearchParams(params)}` : ""}`),
         plans: () => req<Plan[]>("/api/staff/plans"),

adminsite/lib/slug.ts

@@ -0,0 +1,56 @@
+/*
+ * A TypeScript mirror of shared/provision's slug rules, used ONLY to preview the
+ * host a rename would move an instance to while the customer types.
+ *
+ * It is a second implementation of Slugify, BaseSlug and ReservedSlugs, and it
+ * must change in the same commit as the Go one — the same hazard as
+ * web/lib/targets.ts. The preview is a courtesy; the server's 409 is the
+ * boundary, and the two are allowed to disagree without anything breaking.
+ */
+
+/** Mirrors provision.MinSlugLength / MaxSlugLength. */
+export const MIN_SLUG_LENGTH = 3;
+export const MAX_SLUG_LENGTH = 40;
+
+/** Mirrors provision.ReservedSlugs. */
+const RESERVED = new Set([
+    "www", "api", "app", "admin", "auth",
+    "install", "static", "_next", "default",
+]);
+
+/*
+ * The tenant subdomain namespace. Also hardcoded in InstanceRecord.tsx and the
+ * customer instance page; those predate this file and are left alone rather than
+ * refactored under a rename change.
+ */
+export const INSTANCE_DOMAIN = "vantage.hostxtra.co.uk";
+
+/** Mirrors provision.Slugify. */
+export function slugify(name: string): string {
+    return name
+        .toLowerCase()
+        .replace(/[^a-z0-9]+/g, "-")
+        .replace(/^-+|-+$/g, "");
+}
+
+/** Mirrors provision.BaseSlug's truncation. */
+export function baseSlug(name: string): string {
+    return slugify(name).slice(0, MAX_SLUG_LENGTH);
+}
+
+/** The reason a name cannot become a slug, or undefined when it can. */
+export function slugError(name: string): string | undefined {
+    const base = slugify(name);
+    if (base.length < MIN_SLUG_LENGTH) {
+        return `Needs at least ${MIN_SLUG_LENGTH} letters or digits.`;
+    }
+    if (RESERVED.has(base.slice(0, MAX_SLUG_LENGTH))) {
+        return "That name is reserved.";
+    }
+    return undefined;
+}
+
+/** The host an instance on this slug is reached at. */
+export function hostFor(slug: string): string {
+    return `${slug}.${INSTANCE_DOMAIN}`;
+}