feat: count people around

services/api/src/api/v1/operations/radar/people-count.get.js

@@ -0,0 +1,46 @@
+const { ctx } = require("@modjo/core")
+const { reqCtx } = require("@modjo/express/ctx")
+
+const RADAR_DISTANCE_KM = 25000 // 25km in meters
+
+module.exports = function () {
+  const redis = ctx.require("redisHotGeodata")
+
+  async function doRadarPeopleCount(_req) {
+    const { deviceId } = reqCtx.get("session")
+
+    if (!deviceId) {
+      throw new Error("No device found in session")
+    }
+
+    // Get current device location from Redis
+    const devicePosition = await redis.geopos("device", deviceId)
+
+    if (
+      !devicePosition ||
+      !devicePosition[0] ||
+      devicePosition[0].length !== 2
+    ) {
+      throw new Error("Device location not available in Redis")
+    }
+
+    const [longitude, latitude] = devicePosition[0]
+
+    // Use Redis GEORADIUS to get all devices within 25km
+    const devicesData = await redis.georadius(
+      "device",
+      longitude,
+      latitude,
+      RADAR_DISTANCE_KM,
+      "m",
+      "WITHDIST"
+    )
+    const count = devicesData.filter(
+      ([id]) => parseInt(id, 10) !== deviceId
+    ).length
+
+    return { count }
+  }
+
+  return [doRadarPeopleCount]
+}

services/api/src/api/v1/operations/radar/people-count.get.spec.yaml

@@ -0,0 +1,35 @@
+# description: Get count of people within 25km radius of authenticated user's device location
+x-security:
+  - auth: ["user"]
+responses:
+  200:
+    # description: People count within 25km radius
+    content:
+      application/json:
+        schema:
+          type: object
+          properties:
+            count:
+              type: integer
+              minimum: 0
+              description: Number of people within 25km radius
+          required:
+            - count
+  400:
+    # description: Invalid coordinates provided
+    content:
+      application/json:
+        schema:
+          type: object
+          properties:
+            error:
+              type: string
+  500:
+    # description: Internal server error
+    content:
+      application/json:
+        schema:
+          type: object
+          properties:
+            error:
+              type: string