Added zod for validation

lib/api.ts

@@ -1,54 +1,77 @@
+import { z } from 'zod';
+
 const API_URL = 'http://localhost:5000/api';
 
-export interface Vehicle {
-  vin: string;
-  status: string;
-  currentVersion: string;
-  lastHeartbeat: string;
-  groupId?: number;
-  group?: VehicleGroup;
-}
+// --- Zod Schemas ---
 
-export interface VehicleGroup {
-  id: number;
-  name: string;
-  description?: string;
-  vehicles?: Vehicle[];
-}
+// Base schemas to handle circular references if needed, though usually mapped by API
+// defined separately to allow recursive type inference if we went down the z.lazy route,
+// but for now we'll keep it simple as the API returns what it returns.
 
-export interface FirmwareUpdate {
-  id: number;
-  version: string;
-  description?: string;
-  uploadedAt: string;
-}
+export const BaseVehicleGroupSchema = z.object({
+  id: z.number(),
+  name: z.string(),
+  description: z.string().optional().nullable(),
+});
 
-export interface Deployment {
-  id: number;
-  updateId: number;
-  targetVin?: string;
-  targetGroupId?: number;
-  status: string;
-  createdAt: string;
-  update: FirmwareUpdate;
-}
+export const VehicleSchema = z.object({
+  vin: z.string(),
+  status: z.string(),
+  currentVersion: z.string(),
+  lastHeartbeat: z.string(),
+  groupId: z.number().optional().nullable(),
+  group: BaseVehicleGroupSchema.optional().nullable(),
+});
+
+export const VehicleGroupSchema = BaseVehicleGroupSchema.extend({
+  vehicles: z.array(VehicleSchema).optional().nullable(),
+});
+
+export const FirmwareUpdateSchema = z.object({
+  id: z.number(),
+  version: z.string(),
+  description: z.string().optional().nullable(),
+  uploadedAt: z.string(),
+});
+
+export const DeploymentSchema = z.object({
+  id: z.number(),
+  updateId: z.number(),
+  targetVin: z.string().optional().nullable(),
+  targetGroupId: z.number().optional().nullable(),
+  status: z.string(),
+  createdAt: z.string(),
+  update: FirmwareUpdateSchema,
+});
+
+// --- Types Inferred from Schemas ---
+
+export type Vehicle = z.infer<typeof VehicleSchema>;
+export type VehicleGroup = z.infer<typeof VehicleGroupSchema>;
+export type FirmwareUpdate = z.infer<typeof FirmwareUpdateSchema>;
+export type Deployment = z.infer<typeof DeploymentSchema>;
+
+// --- API Functions with Validation ---
 
 export async function fetchVehicles(): Promise<Vehicle[]> {
   const res = await fetch(`${API_URL}/admin/vehicles`);
   if (!res.ok) throw new Error('Failed to fetch vehicles');
-  return res.json();
+  const json = await res.json();
+  return z.array(VehicleSchema).parse(json);
 }
 
 export async function fetchGroups(): Promise<VehicleGroup[]> {
   const res = await fetch(`${API_URL}/admin/groups`);
   if (!res.ok) throw new Error('Failed to fetch groups');
-  return res.json();
+  const json = await res.json();
+  return z.array(VehicleGroupSchema).parse(json);
 }
 
 export async function getUpdates(): Promise<FirmwareUpdate[]> {
   const res = await fetch(`${API_URL}/admin/updates`);
   if (!res.ok) throw new Error('Failed to fetch updates');
-  return res.json();
+  const json = await res.json();
+  return z.array(FirmwareUpdateSchema).parse(json);
 }
 
 export async function createGroup(name: string, description?: string): Promise<VehicleGroup> {
@@ -58,7 +81,8 @@ export async function createGroup(name: string, description?: string): Promise<V
     body: JSON.stringify({ name, description }),
   });
   if (!res.ok) throw new Error('Failed to create group');
-  return res.json();
+  const json = await res.json();
+  return VehicleGroupSchema.parse(json);
 }
 
 export async function updateGroup(id: number, name: string, description?: string): Promise<VehicleGroup> {
@@ -68,7 +92,8 @@ export async function updateGroup(id: number, name: string, description?: string
     body: JSON.stringify({ name, description }),
   });
   if (!res.ok) throw new Error('Failed to update group');
-  return res.json();
+  const json = await res.json();
+  return VehicleGroupSchema.parse(json);
 }
 
 export async function assignVehicleToGroup(groupId: number, vin: string): Promise<void> {
@@ -83,7 +108,8 @@ export async function assignVehicleToGroup(groupId: number, vin: string): Promis
 export async function fetchDeployments(): Promise<Deployment[]> {
   const res = await fetch(`${API_URL}/admin/deployments`);
   if (!res.ok) throw new Error('Failed to fetch deployments');
-  return res.json();
+  const json = await res.json();
+  return z.array(DeploymentSchema).parse(json);
 }
 
 export async function uploadUpdate(formData: FormData): Promise<void> {