5 files changed, 87 insertions, 3 deletions

diff --git a/backend/src/controllers/getRobots.ts b/backend/src/controllers/getRobots.ts
new file mode 100644
index 0000000..b634306
--- /dev/null
+++ b/backend/src/controllers/getRobots.ts
@@ -0,0 +1,56 @@
+import { Request, Response } from "express";
+import { QueryResult } from "pg";
+import db from "../database/postgres.js";
+import redisClient from "../database/redis.js";
+import { ErrorResponse } from "../types/error.js";
+import { Robot, RobotsResponse } from "../types/robot.js";
+
+const CACHE_TTL = 10;
+const ROBOTS_CACHE_KEY = "allMyRobots";
+
+async function getRobots(_req: Request, res: Response) {
+    try {
+        // Check if Redis has cached data to send to frontend
+        const cachedData = await redisClient.get(ROBOTS_CACHE_KEY);
+
+        if (cachedData) {
+            console.log("Data served from Redis cache.");
+            const robots: Robot[] = JSON.parse(cachedData);
+
+            const response: RobotsResponse = {
+                source: "cache",
+                data: robots,
+            };
+
+            return res.status(200).json(response);
+        }
+
+        // Else query database, then save in Redis cache and send to frontend
+        const robotsQuery: QueryResult<Robot> = await db.query(
+            "SELECT * FROM robots ORDER BY id;"
+        );
+        const robots = robotsQuery.rows;
+
+        await redisClient.set(ROBOTS_CACHE_KEY, JSON.stringify(robots), {
+            EX: CACHE_TTL,
+        });
+
+        console.log("Cache miss: data queried from PostgreSQL.");
+        const response: RobotsResponse = {
+            source: "database",
+            data: robots,
+        };
+
+        return res.status(200).json(response);
+    } catch (error) {
+        console.error("Failed to load the robots: ", error);
+        const errorResponse: ErrorResponse = {
+            message: "Internal server error while loading the robots.",
+            error,
+        };
+
+        return res.status(500).json(errorResponse);
+    }
+}
+
+export default getRobots;
diff --git a/backend/src/routes/router.ts b/backend/src/routes/router.ts
index 325b08a..e67a64b 100644
--- a/backend/src/routes/router.ts
+++ b/backend/src/routes/router.ts
@@ -1,6 +1,8 @@
 import { Router } from "express";
 import generateAdmin from "../controllers/generateAdmin.js";
+import getRobots from "../controllers/getRobots.js";
 import loginUser from "../controllers/loginUser.js";
+import authenticateUser from "../middleware/authCheck.js";
 
 const router = Router();
 
@@ -8,5 +10,7 @@ const router = Router();
 router.get("/admin-generation", generateAdmin);
 // Login for registered users
 router.post("/auth/login", loginUser);
+// Get robots from database; protected route
+router.get("/robots", authenticateUser, getRobots);
 
 export default router;
diff --git a/backend/src/types/error.ts b/backend/src/types/error.ts
new file mode 100644
index 0000000..c848e34
--- /dev/null
+++ b/backend/src/types/error.ts
@@ -0,0 +1,4 @@
+export type ErrorResponse = {
+    message: string;
+    error?: unknown;
+};
diff --git a/backend/src/types/robot.ts b/backend/src/types/robot.ts
new file mode 100644
index 0000000..40ce282
--- /dev/null
+++ b/backend/src/types/robot.ts
@@ -0,0 +1,20 @@
+export type RobotPosition = {
+    lat: number;
+    lon: number;
+};
+
+export type Robot = {
+    id: number;
+    name: string;
+    status: "idle" | "moving";
+    lat: number;
+    lon: number;
+    robot_positions: RobotPosition[];
+    created_at: string;
+    updated_at: string;
+};
+
+export type RobotsResponse = {
+    source: "cache" | "database";
+    data: Robot[];
+};
diff --git a/backend/src/types/user.ts b/backend/src/types/user.ts
index 875072c..b2c7ffc 100644
--- a/backend/src/types/user.ts
+++ b/backend/src/types/user.ts
@@ -1,18 +1,18 @@
 export type AdminCreationResult = {
     id: string;
     email: string;
-    created_at: Date;
+    created_at: string;
 };
 
 export type AuthorizedUser = {
     id: string;
     email: string;
-    createdAt: Date;
+    createdAt: string;
 };
 
 export type DatabaseUser = {
     id: string;
     email: string;
     password_hash: string;
-    created_at: Date;
+    created_at: string;
 };