feat: Implement RSSI service for iOS and Web platforms

- Added IosRssiService to handle synthetic RSSI data for iOS.
- Created WebRssiService to simulate RSSI scanning on the web.
- Defined shared types for WifiNetwork and RssiService in rssi.service.ts.
- Introduced simulation service to generate synthetic sensing data.
- Implemented WebSocket service for real-time data handling with reconnection logic.
- Established Zustand stores for managing application state related to MAT and pose data.
- Developed theme context and utility functions for consistent styling and formatting.
- Added type definitions for various application entities including API responses and sensing data.
- Created utility functions for color mapping and URL validation.
- Configured TypeScript settings for the mobile application.

ui/mobile/src/services/api.service.ts

@@ -0,0 +1,92 @@
+import axios, { type AxiosError, type AxiosInstance, type AxiosRequestConfig } from 'axios';
+import { API_POSE_FRAMES_PATH, API_POSE_STATUS_PATH, API_POSE_ZONES_PATH } from '@/constants/api';
+import type { ApiError, HistoricalFrames, PoseStatus, ZoneConfig } from '@/types/api';
+
+class ApiService {
+  private baseUrl = '';
+  private client: AxiosInstance;
+
+  constructor() {
+    this.client = axios.create({
+      timeout: 5000,
+      headers: {
+        Accept: 'application/json',
+        'Content-Type': 'application/json',
+      },
+    });
+  }
+
+  setBaseUrl(url: string): void {
+    this.baseUrl = url ?? '';
+  }
+
+  private buildUrl(path: string): string {
+    if (!this.baseUrl) {
+      return path;
+    }
+    if (path.startsWith('http://') || path.startsWith('https://')) {
+      return path;
+    }
+    const normalized = this.baseUrl.replace(/\/$/, '');
+    return `${normalized}${path.startsWith('/') ? path : `/${path}`}`;
+  }
+
+  private normalizeError(error: unknown): ApiError {
+    if (axios.isAxiosError(error)) {
+      const axiosError = error as AxiosError<{ message?: string }>;
+      const message =
+        axiosError.response?.data && typeof axiosError.response.data === 'object' && 'message' in axiosError.response.data
+          ? String((axiosError.response.data as { message?: string }).message)
+          : axiosError.message || 'Request failed';
+      return {
+        message,
+        status: axiosError.response?.status,
+        code: axiosError.code,
+        details: axiosError.response?.data,
+      };
+    }
+
+    if (error instanceof Error) {
+      return { message: error.message };
+    }
+
+    return { message: 'Unknown error' };
+  }
+
+  private async requestWithRetry<T>(config: AxiosRequestConfig, retriesLeft: number): Promise<T> {
+    try {
+      const response = await this.client.request<T>({
+        ...config,
+        url: this.buildUrl(config.url || ''),
+      });
+      return response.data;
+    } catch (error) {
+      if (retriesLeft > 0) {
+        return this.requestWithRetry<T>(config, retriesLeft - 1);
+      }
+      throw this.normalizeError(error);
+    }
+  }
+
+  get<T>(path: string): Promise<T> {
+    return this.requestWithRetry<T>({ method: 'GET', url: path }, 2);
+  }
+
+  post<T>(path: string, body: unknown): Promise<T> {
+    return this.requestWithRetry<T>({ method: 'POST', url: path, data: body }, 2);
+  }
+
+  getStatus(): Promise<PoseStatus> {
+    return this.get<PoseStatus>(API_POSE_STATUS_PATH);
+  }
+
+  getZones(): Promise<ZoneConfig[]> {
+    return this.get<ZoneConfig[]>(API_POSE_ZONES_PATH);
+  }
+
+  getFrames(limit: number): Promise<HistoricalFrames> {
+    return this.get<HistoricalFrames>(`${API_POSE_FRAMES_PATH}?limit=${encodeURIComponent(String(limit))}`);
+  }
+}
+
+export const apiService = new ApiService();

ui/mobile/src/services/rssi.service.android.ts

@@ -0,0 +1,62 @@
+import type { RssiService, WifiNetwork } from './rssi.service';
+import WifiManager from '@react-native-wifi-reborn';
+
+type NativeWifiNetwork = {
+  SSID?: string;
+  BSSID?: string;
+  level?: number;
+  levelDbm?: number;
+};
+
+class AndroidRssiService implements RssiService {
+  private timer: ReturnType<typeof setInterval> | null = null;
+  private listeners = new Set<(networks: WifiNetwork[]) => void>();
+
+  startScanning(intervalMs: number): void {
+    this.stopScanning();
+    this.scanOnce();
+    this.timer = setInterval(() => {
+      this.scanOnce();
+    }, intervalMs);
+  }
+
+  stopScanning(): void {
+    if (this.timer) {
+      clearInterval(this.timer);
+      this.timer = null;
+    }
+  }
+
+  subscribe(listener: (networks: WifiNetwork[]) => void): () => void {
+    this.listeners.add(listener);
+    return () => {
+      this.listeners.delete(listener);
+    };
+  }
+
+  private async scanOnce(): Promise<void> {
+    try {
+      const results = (await WifiManager.loadWifiList()) as NativeWifiNetwork[];
+      const mapped = results.map((item) => ({
+        ssid: item.SSID || '',
+        bssid: item.BSSID,
+        level: typeof item.level === 'number' ? item.level : typeof item.levelDbm === 'number' ? item.levelDbm : -100,
+      }));
+      this.broadcast(mapped.filter((n) => n.ssid.length > 0));
+    } catch {
+      this.broadcast([]);
+    }
+  }
+
+  private broadcast(networks: WifiNetwork[]): void {
+    this.listeners.forEach((listener) => {
+      try {
+        listener(networks);
+      } catch {
+        // listener safety
+      }
+    });
+  }
+}
+
+export const rssiService = new AndroidRssiService();

ui/mobile/src/services/rssi.service.ios.ts

@@ -0,0 +1,41 @@
+import type { RssiService, WifiNetwork } from './rssi.service';
+
+class IosRssiService implements RssiService {
+  private timer: ReturnType<typeof setInterval> | null = null;
+  private listeners = new Set<(networks: WifiNetwork[]) => void>();
+
+  startScanning(intervalMs: number): void {
+    console.warn('iOS RSSI scanning not available; returning synthetic network data.');
+    this.stopScanning();
+    this.timer = setInterval(() => {
+      this.broadcast([{ ssid: 'WiFi-DensePose', bssid: undefined, level: -60 }]);
+    }, intervalMs);
+    this.broadcast([{ ssid: 'WiFi-DensePose', bssid: undefined, level: -60 }]);
+  }
+
+  stopScanning(): void {
+    if (this.timer) {
+      clearInterval(this.timer);
+      this.timer = null;
+    }
+  }
+
+  subscribe(listener: (networks: WifiNetwork[]) => void): () => void {
+    this.listeners.add(listener);
+    return () => {
+      this.listeners.delete(listener);
+    };
+  }
+
+  private broadcast(networks: WifiNetwork[]): void {
+    this.listeners.forEach((listener) => {
+      try {
+        listener(networks);
+      } catch {
+        // listener safety
+      }
+    });
+  }
+}
+
+export const rssiService = new IosRssiService();

ui/mobile/src/services/rssi.service.ts

@@ -0,0 +1,33 @@
+export interface WifiNetwork {
+  ssid: string;
+  bssid?: string;
+  level: number;
+}
+
+export interface RssiService {
+  startScanning(intervalMs: number): void;
+  stopScanning(): void;
+  subscribe(listener: (networks: WifiNetwork[]) => void): () => void;
+}
+
+// Metro resolves the correct platform file automatically:
+//   rssi.service.android.ts  (Android)
+//   rssi.service.ios.ts      (iOS)
+//   rssi.service.web.ts      (Web)
+// This file only exports the shared types.
+// The platform entry is re-exported from the index barrel below.
+
+import { Platform } from 'react-native';
+
+// Lazy require to avoid bundling native modules on web
+function getPlatformService(): RssiService {
+  if (Platform.OS === 'android') {
+    return require('./rssi.service.android').rssiService;
+  } else if (Platform.OS === 'ios') {
+    return require('./rssi.service.ios').rssiService;
+  } else {
+    return require('./rssi.service.web').rssiService;
+  }
+}
+
+export const rssiService: RssiService = getPlatformService();

ui/mobile/src/services/rssi.service.web.ts

@@ -0,0 +1,46 @@
+import type { RssiService, WifiNetwork } from './rssi.service';
+
+class WebRssiService implements RssiService {
+  private timer: ReturnType<typeof setInterval> | null = null;
+  private listeners = new Set<(networks: WifiNetwork[]) => void>();
+
+  startScanning(intervalMs: number): void {
+    console.warn('Web RSSI scanning not available; returning synthetic network data.');
+    this.stopScanning();
+    this.timer = setInterval(() => {
+      this.broadcast([
+        { ssid: 'WiFi-DensePose', bssid: 'AA:BB:CC:DD:EE:01', level: -55 },
+        { ssid: 'WiFi-Guest', bssid: 'AA:BB:CC:DD:EE:02', level: -72 },
+      ]);
+    }, intervalMs);
+    this.broadcast([
+      { ssid: 'WiFi-DensePose', bssid: 'AA:BB:CC:DD:EE:01', level: -55 },
+    ]);
+  }
+
+  stopScanning(): void {
+    if (this.timer) {
+      clearInterval(this.timer);
+      this.timer = null;
+    }
+  }
+
+  subscribe(listener: (networks: WifiNetwork[]) => void): () => void {
+    this.listeners.add(listener);
+    return () => {
+      this.listeners.delete(listener);
+    };
+  }
+
+  private broadcast(networks: WifiNetwork[]): void {
+    this.listeners.forEach((listener) => {
+      try {
+        listener(networks);
+      } catch {
+        // listener safety
+      }
+    });
+  }
+}
+
+export const rssiService = new WebRssiService();

ui/mobile/src/services/simulation.service.ts

@@ -0,0 +1,107 @@
+import {
+  BREATHING_BAND_AMPLITUDE,
+  BREATHING_BAND_MIN,
+  BREATHING_BPM_MAX,
+  BREATHING_BPM_MIN,
+  HEART_BPM_MAX,
+  HEART_BPM_MIN,
+  MOTION_BAND_AMPLITUDE,
+  MOTION_BAND_MIN,
+  RSSI_AMPLITUDE_DBM,
+  RSSI_BASE_DBM,
+  SIMULATION_GRID_SIZE,
+  SIMULATION_TICK_INTERVAL_MS,
+  SIGNAL_FIELD_PRESENCE_LEVEL,
+  VARIANCE_AMPLITUDE,
+  VARIANCE_BASE,
+} from '@/constants/simulation';
+import type { SensingFrame } from '@/types/sensing';
+
+function gaussian(x: number, y: number, cx: number, cy: number, sigma: number): number {
+  const dx = x - cx;
+  const dy = y - cy;
+  return Math.exp(-(dx * dx + dy * dy) / (2 * sigma * sigma));
+}
+
+function clamp(v: number, min: number, max: number): number {
+  return Math.max(min, Math.min(max, v));
+}
+
+export function generateSimulatedData(timeMs = Date.now()): SensingFrame {
+  const t = timeMs / 1000;
+
+  const baseRssi = RSSI_BASE_DBM + Math.sin(t * 0.5) * RSSI_AMPLITUDE_DBM;
+  const variance = VARIANCE_BASE + Math.sin(t * 0.1) * VARIANCE_AMPLITUDE;
+  const motionBand = MOTION_BAND_MIN + Math.abs(Math.sin(t * 0.3)) * MOTION_BAND_AMPLITUDE;
+  const breathingBand = BREATHING_BAND_MIN + Math.abs(Math.sin(t * 0.05)) * BREATHING_BAND_AMPLITUDE;
+
+  const isPresent = variance > SIGNAL_FIELD_PRESENCE_LEVEL;
+  const isActive = motionBand > 0.12;
+
+  const grid = SIMULATION_GRID_SIZE;
+  const cx = grid / 2;
+  const cy = grid / 2;
+  const bodyX = cx + 3 * Math.sin(t * 0.2);
+  const bodyY = cy + 2 * Math.cos(t * 0.15);
+  const breathX = cx + 4 * Math.sin(t * 0.04);
+  const breathY = cy + 4 * Math.cos(t * 0.04);
+
+  const values: number[] = [];
+  for (let z = 0; z < grid; z += 1) {
+    for (let x = 0; x < grid; x += 1) {
+      let value = Math.max(0, 1 - Math.sqrt((x - cx) ** 2 + (z - cy) ** 2) / (grid * 0.7)) * 0.3;
+      value += gaussian(x, z, bodyX, bodyY, 3.4) * (0.3 + motionBand * 3);
+      value += gaussian(x, z, breathX, breathY, 6) * (0.15 + breathingBand * 2);
+      if (!isPresent) {
+        value *= 0.7;
+      }
+      values.push(clamp(value, 0, 1));
+    }
+  }
+
+  const dominantFreqHz = 0.3 + Math.sin(t * 0.02) * 0.1;
+  const breathingBpm = BREATHING_BPM_MIN + ((Math.sin(t * 0.07) + 1) * 0.5) * (BREATHING_BPM_MAX - BREATHING_BPM_MIN);
+  const hrProxy = HEART_BPM_MIN + ((Math.sin(t * 0.09) + 1) * 0.5) * (HEART_BPM_MAX - HEART_BPM_MIN);
+  const confidence = 0.6 + Math.abs(Math.sin(t * 0.03)) * 0.4;
+
+  return {
+    type: 'sensing_update',
+    timestamp: timeMs,
+    source: 'simulated',
+    tick: Math.floor(t / (SIMULATION_TICK_INTERVAL_MS / 1000)),
+    nodes: [
+      {
+        node_id: 1,
+        rssi_dbm: baseRssi,
+        position: [2, 0, 1.5],
+        amplitude: [baseRssi],
+        subcarrier_count: 1,
+      },
+    ],
+    features: {
+      mean_rssi: baseRssi,
+      variance,
+      motion_band_power: motionBand,
+      breathing_band_power: breathingBand,
+      spectral_entropy: 1 - clamp(Math.abs(dominantFreqHz - 0.3), 0, 1),
+      std: Math.sqrt(Math.abs(variance)),
+      dominant_freq_hz: dominantFreqHz,
+      change_points: Math.max(0, Math.floor(variance * 2)),
+      spectral_power: motionBand + breathingBand,
+    },
+    classification: {
+      motion_level: isActive ? 'active' : isPresent ? 'present_still' : 'absent',
+      presence: isPresent,
+      confidence: isPresent ? 0.75 + Math.abs(Math.sin(t * 0.03)) * 0.2 : 0.5 + Math.abs(Math.cos(t * 0.03)) * 0.3,
+    },
+    signal_field: {
+      grid_size: [grid, 1, grid],
+      values,
+    },
+    vital_signs: {
+      breathing_bpm: breathingBpm,
+      hr_proxy_bpm: hrProxy,
+      confidence,
+    },
+  };
+}

ui/mobile/src/services/ws.service.ts

@@ -0,0 +1,170 @@
+import { SIMULATION_TICK_INTERVAL_MS } from '@/constants/simulation';
+import { MAX_RECONNECT_ATTEMPTS, RECONNECT_DELAYS, WS_PATH } from '@/constants/websocket';
+import { usePoseStore } from '@/stores/poseStore';
+import { generateSimulatedData } from '@/services/simulation.service';
+import type { ConnectionStatus, SensingFrame } from '@/types/sensing';
+
+type FrameListener = (frame: SensingFrame) => void;
+
+class WsService {
+  private ws: WebSocket | null = null;
+  private listeners = new Set<FrameListener>();
+  private reconnectAttempt = 0;
+  private reconnectTimer: ReturnType<typeof setTimeout> | null = null;
+  private simulationTimer: ReturnType<typeof setInterval> | null = null;
+  private targetUrl = '';
+  private active = false;
+  private status: ConnectionStatus = 'disconnected';
+
+  connect(url: string): void {
+    this.targetUrl = url;
+    this.active = true;
+    this.reconnectAttempt = 0;
+
+    if (!url) {
+      this.handleStatusChange('simulated');
+      this.startSimulation();
+      return;
+    }
+
+    if (this.ws && (this.ws.readyState === WebSocket.OPEN || this.ws.readyState === WebSocket.CONNECTING)) {
+      return;
+    }
+
+    this.handleStatusChange('connecting');
+
+    try {
+      const endpoint = this.buildWsUrl(url);
+      const socket = new WebSocket(endpoint);
+      this.ws = socket;
+
+      socket.onopen = () => {
+        this.reconnectAttempt = 0;
+        this.stopSimulation();
+        this.handleStatusChange('connected');
+      };
+
+      socket.onmessage = (evt) => {
+        try {
+          const raw = typeof evt.data === 'string' ? evt.data : JSON.stringify(evt.data);
+          const frame = JSON.parse(raw) as SensingFrame;
+          this.listeners.forEach((listener) => listener(frame));
+        } catch {
+          // ignore malformed frames
+        }
+      };
+
+      socket.onerror = () => {
+        // handled by onclose
+      };
+
+      socket.onclose = (evt) => {
+        this.ws = null;
+        if (!this.active) {
+          this.handleStatusChange('disconnected');
+          return;
+        }
+        if (evt.code === 1000) {
+          this.handleStatusChange('disconnected');
+          return;
+        }
+        this.scheduleReconnect();
+      };
+    } catch {
+      this.scheduleReconnect();
+    }
+  }
+
+  disconnect(): void {
+    this.active = false;
+    this.clearReconnectTimer();
+    this.stopSimulation();
+    if (this.ws) {
+      this.ws.close(1000, 'client disconnect');
+      this.ws = null;
+    }
+    this.handleStatusChange('disconnected');
+  }
+
+  subscribe(listener: FrameListener): () => void {
+    this.listeners.add(listener);
+    return () => {
+      this.listeners.delete(listener);
+    };
+  }
+
+  getStatus(): ConnectionStatus {
+    return this.status;
+  }
+
+  private buildWsUrl(rawUrl: string): string {
+    const parsed = new URL(rawUrl);
+    const proto = parsed.protocol === 'https:' || parsed.protocol === 'wss:' ? 'wss:' : 'ws:';
+    // Sensing server runs WS on port 3001 at /ws/sensing
+    // If the HTTP server is on port 3000, connect WS to 3001
+    const wsHost = parsed.port === '3000'
+      ? `${parsed.hostname}:3001`
+      : parsed.host;
+    const wsPath = parsed.port === '3000' ? '/ws/sensing' : WS_PATH;
+    return `${proto}//${wsHost}${wsPath}`;
+  }
+
+  private handleStatusChange(status: ConnectionStatus): void {
+    if (status === this.status) {
+      return;
+    }
+    this.status = status;
+    usePoseStore.getState().setConnectionStatus(status);
+  }
+
+  private scheduleReconnect(): void {
+    if (!this.active) {
+      this.handleStatusChange('disconnected');
+      return;
+    }
+
+    if (this.reconnectAttempt >= MAX_RECONNECT_ATTEMPTS) {
+      this.handleStatusChange('simulated');
+      this.startSimulation();
+      return;
+    }
+
+    const delay = RECONNECT_DELAYS[Math.min(this.reconnectAttempt, RECONNECT_DELAYS.length - 1)];
+    this.reconnectAttempt += 1;
+    this.clearReconnectTimer();
+    this.reconnectTimer = setTimeout(() => {
+      this.reconnectTimer = null;
+      this.connect(this.targetUrl);
+    }, delay);
+    this.startSimulation();
+  }
+
+  private startSimulation(): void {
+    if (this.simulationTimer) {
+      return;
+    }
+    this.simulationTimer = setInterval(() => {
+      this.handleStatusChange('simulated');
+      const frame = generateSimulatedData();
+      this.listeners.forEach((listener) => {
+        listener(frame);
+      });
+    }, SIMULATION_TICK_INTERVAL_MS);
+  }
+
+  private stopSimulation(): void {
+    if (this.simulationTimer) {
+      clearInterval(this.simulationTimer);
+      this.simulationTimer = null;
+    }
+  }
+
+  private clearReconnectTimer(): void {
+    if (this.reconnectTimer) {
+      clearTimeout(this.reconnectTimer);
+      this.reconnectTimer = null;
+    }
+  }
+}
+
+export const wsService = new WsService();