// Copyright 2026 Google LLC

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

// http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

// [START imports]

// Dependencies for callable functions.

import 'package:firebase_functions/firebase_functions.dart';

// [END imports]

void main(List<String> args) async {

await fireUp(args, (firebase) {

// [START allAdd]

// [START addFunctionTrigger]

// Adds two numbers to each other.

firebase.https.onCall(name: 'addNumbers', (request, response) async {

// [END addFunctionTrigger]

// [START readAddData]

// Numbers passed from the client.

final data = request.data as Map<String, Object?>?;

final firstNumber = data?['firstNumber'];

final secondNumber = data?['secondNumber'];

// [END readAddData]

// [START addHttpsError]

// Checking that attributes are present and are numbers.

if (firstNumber is! num || secondNumber is! num) {

// Throwing an HttpsError so that the client gets the error details.

throw InvalidArgumentError(

'The function must be called with two arguments "firstNumber" and "secondNumber" which must both be numbers.',

);

}

// [END addHttpsError]

// [START authIntegration]

// Authentication / user information is automatically added to the request.

final uid = request.auth?.uid;

final token = request.auth?.token;

final name = token?['name'];

final picture = token?['picture'];

final email = token?['email'];

// Use variables to suppress 'unused' lint warnings

print(

'User details: uid=$uid, name=$name, picture=$picture, email=$email',

);

// [END authIntegration]

// [START returnAddData]

// returning result.

return CallableResult({

'firstNumber': firstNumber,

'secondNumber': secondNumber,

'operator': '+',

'operationResult': firstNumber + secondNumber,

});

// [END returnAddData]

});

// [END allAdd]

});

}