add initial OtaWifiProvider implementation

src/app/app.module.ts

@@ -8,6 +8,7 @@ import { openSenseApp } from './app.component';
 import { HomePage } from '../pages/home/home';
 import { ApiProvider } from '../providers/api/api';
 import { HttpClientModule } from '@angular/common/http';
+import { OtaWifiProvider } from '../providers/ota-wifi/ota-wifi';
 
 @NgModule({
   declarations: [
@@ -28,7 +29,8 @@ import { HttpClientModule } from '@angular/common/http';
     StatusBar,
     SplashScreen,
     {provide: ErrorHandler, useClass: IonicErrorHandler},
-    ApiProvider
+    ApiProvider,
+    OtaWifiProvider
   ]
 })
 export class AppModule {}

src/providers/ota-wifi/ota-wifi.ts

@@ -0,0 +1,73 @@
+import { Injectable } from '@angular/core';
+import { HttpClient } from '@angular/common/http';
+import { Platform } from 'ionic-angular';
+
+// use global var as no @ionic-native/wifiwizard2 package is available yet
+declare var WifiWizard2: any;
+
+// corresponding to the initial MCU firmware
+const SSID_PREFIX = 'sensebox';
+const SENSEBOX_API = 'http://192.168.0.1:80';
+
+/*
+  Interface for uploading a binary to a senseBox MCU.
+*/
+@Injectable()
+export class OtaWifiProvider {
+  public strategy: WifiStrategy
+
+  constructor(private platform: Platform, private http: HttpClient) {
+    this.selectStrategy()
+  }
+
+  private selectStrategy (): WifiStrategy {
+    try {
+      // check if plugin is available (e.g. not in browser builds)
+      WifiWizard2
+
+      if (
+        this.platform.is('android') ||
+        this.platform.is('ios') && this.platform.version().major >= 11
+      ) {
+        this.strategy = WifiStrategy.Automatic
+      } else {
+        this.strategy = WifiStrategy.Manual
+      }
+    } catch (err) {
+      this.strategy = WifiStrategy.Unavailable
+    }
+
+    return this.strategy;
+  }
+
+  async findSenseboxes (): Promise<string> {
+    if (this.strategy != WifiStrategy.Automatic)
+      throw Error('can not search for WiFi networks on this platform')
+
+    return WifiWizard2.scan()
+      .then(n => n.filter(n.SSID.includes(SSID_PREFIX)))
+      .then(n => n.map(n => n.SSID))
+  }
+
+  async connectToSensebox (ssid: string): Promise<any> {
+    if (this.strategy != WifiStrategy.Automatic)
+      throw Error('can not connect to WiFi network on this platform')
+
+    return this.platform.is('ios')
+      ? WifiWizard2.iOSConnectNetwork(ssid)
+      : WifiWizard2.connect(ssid, true)
+  }
+
+  async uploadFirmware (blob: ArrayBufferLike): Promise<any> {
+    return this.http.post(SENSEBOX_API, blob)
+  }
+
+}
+
+// TODO: replace with "WifiCapabilities".
+// makes it easier to check in each functions if required functionality is available
+enum WifiStrategy {
+  Automatic,   // android, iOS 11+
+  Manual,      // older iOS
+  Unavailable, // browser
+}