feat(frontend): fecth and display sensor data

mercury_frontend/lib/main.dart

@@ -1,7 +1,15 @@
 import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'sensor_provider.dart';
+import 'package:timeago/timeago.dart' as timeago;
 
 void main() {
-  runApp(const MyApp());
+  runApp(
+    ChangeNotifierProvider(
+      create: (context) => SensorProvider(),
+      child: const MyApp(),
+    ),
+  );
 }
 
 class MyApp extends StatelessWidget {
@@ -10,30 +18,28 @@ class MyApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
-      title: 'Flutter Demo',
+      title: 'Sensor App',
       theme: ThemeData(
-        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
+        primarySwatch: Colors.blue,
       ),
-      home: const MyHomePage(title: 'Flutter Demo Home Page'),
+      home: const SensorScreen(),
     );
   }
 }
 
-class MyHomePage extends StatefulWidget {
-  const MyHomePage({super.key, required this.title});
-
-  final String title;
+class SensorScreen extends StatefulWidget {
+  const SensorScreen({super.key});
 
   @override
-  State<MyHomePage> createState() => _MyHomePageState();
+  _SensorScreenState createState() => _SensorScreenState();
 }
 
-class _MyHomePageState extends State<MyHomePage> {
-  int _counter = 0;
-
-  void _incrementCounter() {
-    setState(() {
-      _counter++;
+class _SensorScreenState extends State<SensorScreen> {
+  @override
+  void initState() {
+    super.initState();
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      Provider.of<SensorProvider>(context, listen: false).fetchData();
     });
   }
 
@@ -41,25 +47,37 @@ class _MyHomePageState extends State<MyHomePage> {
   Widget build(BuildContext context) {
     return Scaffold(
       appBar: AppBar(
-        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
-        title: Text(widget.title),
+        title: const Text('Mercury'),
       ),
       body: Center(
-        child: Column(
+        child: Consumer<SensorProvider>(
+          builder: (context, sensorProvider, child) {
+            if (sensorProvider.sensorData == null) {
+              if (sensorProvider.error != null) {
+                return Text('Error: ${sensorProvider.error}');
+              }
+              return const CircularProgressIndicator();
+            } else {
+              final data = sensorProvider.sensorData!;
+              final timeAgo = timeago.format(DateTime.fromMillisecondsSinceEpoch(data.timestamp));
+              return Column(
                 mainAxisAlignment: MainAxisAlignment.center,
-          children: <Widget>[
-            const Text('You have pushed the button this many times:'),
-            Text(
-              '$_counter',
-              style: Theme.of(context).textTheme.headlineMedium,
-            ),
+                children: [
+                  Text('🌡️ Temperature: ${data.temperature}°C'),
+                  Text('💧 Humidity: ${data.humidity}%'),
+                  Text('❄️ Dew Point: ${data.dewPoint}°C'),
+                  Text('🕒 $timeAgo'),
                 ],
+              );
+            }
+          },
         ),
       ),
       floatingActionButton: FloatingActionButton(
-        onPressed: _incrementCounter,
-        tooltip: 'Increment',
-        child: const Icon(Icons.add),
+        onPressed: () {
+          Provider.of<SensorProvider>(context, listen: false).fetchData();
+        },
+        child: const Icon(Icons.refresh),
       ),
     );
   }

mercury_frontend/lib/sensor_data.dart

@@ -0,0 +1,22 @@
+class SensorData {
+  final double temperature;
+  final double humidity;
+  final double dewPoint;
+  final int timestamp;
+
+  SensorData({
+    required this.temperature,
+    required this.humidity,
+    required this.dewPoint,
+    required this.timestamp,
+  });
+
+  factory SensorData.fromJson(Map<String, dynamic> json) {
+    return SensorData(
+      temperature: json['temperature'],
+      humidity: json['humidity'],
+      dewPoint: json['dewPoint'],
+      timestamp: json['timestamp'],
+    );
+  }
+}

mercury_frontend/lib/sensor_provider.dart

@@ -0,0 +1,23 @@
+import 'package:flutter/material.dart';
+import 'sensor_data.dart';
+import 'sensor_service.dart';
+
+class SensorProvider with ChangeNotifier {
+  final SensorService _service = SensorService();
+  SensorData? _sensorData;
+
+  Error? _error;
+
+  SensorData? get sensorData => _sensorData;
+
+  Error? get error => _error;
+
+  Future<void> fetchData() async {
+    try {
+      _sensorData = await _service.fetchSensorData();
+    } catch (e) {
+      _error = e as Error;
+    }
+    notifyListeners();
+  }
+}

mercury_frontend/lib/sensor_service.dart

@@ -0,0 +1,17 @@
+import 'dart:convert';
+import 'package:http/http.dart' as http;
+import 'sensor_data.dart';
+
+class SensorService {
+  final String url = 'https://mercury.segin.one/sensor';
+
+  Future<SensorData> fetchSensorData() async {
+    final response = await http.get(Uri.parse(url));
+
+    if (response.statusCode == 200) {
+      return SensorData.fromJson(json.decode(response.body));
+    } else {
+      throw Exception('Failed to load sensor data');
+    }
+  }
+}

mercury_frontend/pubspec.lock

@@ -75,6 +75,30 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  http:
+    dependency: "direct main"
+    description:
+      name: http
+      sha256: fe7ab022b76f3034adc518fb6ea04a82387620e19977665ea18d30a1cf43442f
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.3.0"
+  http_parser:
+    dependency: transitive
+    description:
+      name: http_parser
+      sha256: "178d74305e7866013777bab2c3d8726205dc5a4dd935297175b19a23a2e66571"
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.1.2"
+  intl:
+    dependency: transitive
+    description:
+      name: intl
+      sha256: d6f56758b7d3014a48af9701c085700aac781a92a87a62b1333b46d8879661cf
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.19.0"
   leak_tracker:
     dependency: transitive
     description:
@@ -131,6 +155,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.16.0"
+  nested:
+    dependency: transitive
+    description:
+      name: nested
+      sha256: "03bac4c528c64c95c722ec99280375a6f2fc708eec17c7b3f07253b626cd2a20"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.0"
   path:
     dependency: transitive
     description:
@@ -139,6 +171,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.9.1"
+  provider:
+    dependency: "direct main"
+    description:
+      name: provider
+      sha256: c8a055ee5ce3fd98d6fc872478b03823ffdb448699c6ebdbbc71d59b596fd48c
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.1.2"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -192,6 +232,22 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.7.4"
+  timeago:
+    dependency: "direct main"
+    description:
+      name: timeago
+      sha256: "054cedf68706bb142839ba0ae6b135f6b68039f0b8301cbe8784ae653d5ff8de"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.7.0"
+  typed_data:
+    dependency: transitive
+    description:
+      name: typed_data
+      sha256: f9049c039ebfeb4cf7a7104a675823cd72dba8297f264b6637062516699fa006
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.4.0"
   vector_math:
     dependency: transitive
     description:
@@ -208,6 +264,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "14.3.1"
+  web:
+    dependency: transitive
+    description:
+      name: web
+      sha256: cd3543bd5798f6ad290ea73d210f423502e71900302dde696f8bff84bf89a1cb
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.0"
 sdks:
   dart: ">=3.7.0 <4.0.0"
   flutter: ">=3.18.0-18.0.pre.54"

mercury_frontend/pubspec.yaml

@@ -34,6 +34,9 @@ dependencies:
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^1.0.8
+  provider: ^6.1.2
+  http: ^1.3.0
+  timeago: ^3.7.0
 
 dev_dependencies:
   flutter_test: