// Copyright 2024 The Flutter Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file.

import 'package:firebase_ai/firebase_ai.dart'; import 'package:firebase_core/firebase_core.dart'; import 'package:flutter/material.dart'; import 'package:flutter_ai_toolkit/flutter_ai_toolkit.dart';

// from flutterfire config: https://firebase.google.com/docs/flutter/setup import '../firebase_options.dart';

void main() async { WidgetsFlutterBinding.ensureInitialized(); await Firebase.initializeApp(options: DefaultFirebaseOptions.currentPlatform); runApp(const App()); }

class App extends StatelessWidget { static const title = 'Example: Function Calls';

const App({super.key});

@override Widget build(BuildContext context) => const MaterialApp(title: title, home: ChatPage()); }

class ChatPage extends StatelessWidget { const ChatPage({super.key});

@override Widget build(BuildContext context) => Scaffold( appBar: AppBar(title: const Text(App.title)), body: LlmChatView( provider: FirebaseProvider( model: FirebaseAI.googleAI().generativeModel( model: 'gemini-2.0-flash', tools: [ Tool.functionDeclarations([ FunctionDeclaration( 'get_temperature', 'Get the current local temperature', parameters: {}, ), FunctionDeclaration( 'get_time', 'Get the current local time', parameters: {}, ), FunctionDeclaration( 'c_to_f', 'Convert a temperature from Celsius to Fahrenheit', parameters: { 'temperature': Schema.number( description: 'The temperature in Celsius', ), }, ), ]), ], ), onFunctionCall: _onFunctionCall, ), suggestions: [ 'can you get the current time?', 'can you get the current time and temp?', 'can you get the current temp in Fahrenheit?', ], welcomeMessage: ''' Welcome to the function calls example! This example includes three tools:

• current time: always returns 1970-01-01T00:00:00Z
• current temperature: always returns 0°C
• convert from Celsius to Fahrenheit

The hardcoded values are for demonstration purposes. Not only can you ask Gemini to use these tools one at time, like:

can you get the current time?

but you can ask them in combination, like:

can you get the current time and temp?

you can even ask it to use the results of one function call in another, like:

can you get the current temp in Fahrenheit? ''', ), );

// note: we're not actually calling any external APIs in this example Future<Map<String, Object?>?> _onFunctionCall( FunctionCall functionCall, ) async => switch (functionCall.name) { 'get_temperature' => {'temperature': 0, 'unit': 'C'}, 'get_time' => {'time': DateTime(1970, 1, 1).toIso8601String()}, 'c_to_f' => { 'temperature': (functionCall.args['temperature'] as num).toDouble() * 1.8 + 32, }, _ => throw Exception('Unknown function call: ${functionCall.name}'), }; }