send_fcm_message_using_http_v1.ts

import axios from 'axios';

/**
 * Sends an FCM message using the HTTP v1 API
 * @param serviceAccountPath Path to your service account JSON file
 * @param projectId Your Firebase project ID
 * @param token The FCM registration token of the target device
 * @param title The notification title
 * @param body The notification body
 * @param data Optional data payload
 * @returns Promise that resolves with the response
 */
export async function sendFCMMessage(
  serviceAccountPath: string,
  projectId: string,
  token: string,
  title: string,
  body: string,
  data?: Record<string, string>
): Promise<any> {
  const url = `https://fcm.googleapis.com/v1/projects/${projectId}/messages:send`;
  
  // Get access token from service account
  const accessToken = await getAccessToken(serviceAccountPath);
  
  const message = {
    message: {
      token,
      notification: {
        title,
        body,
      },
      data,
    }
  };

  try {
    const response = await axios.post(
      url,
      message,
      {
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${accessToken}`
        }
      }
    );
    console.log('Successfully sent message:', response.data);
    return response.data;
  } catch (error) {
    console.error('Error sending message:', error);
    throw error;
  }
}

/**
 * Gets an access token for FCM API calls
 * @param serviceAccountPath Path to your service account JSON file
 * @returns Promise that resolves with the access token
 */
async function getAccessToken(serviceAccountPath: string): Promise<string> {
  // You'll need to implement this function using the Google Auth library
  // This is just a placeholder
  // Install: npm install googleapis
  const { GoogleAuth } = require('google-auth-library');
  const auth = new GoogleAuth({
    keyFile: serviceAccountPath,
    scopes: ['https://www.googleapis.com/auth/firebase.messaging'],
  });
  const accessToken = await auth.getAccessToken();
  return accessToken;
}

/**
 * Sends an FCM message to a topic using the HTTP v1 API
 * @param serviceAccountPath Path to your service account JSON file
 * @param projectId Your Firebase project ID
 * @param topic The FCM topic to send to (without the /topics/ prefix)
 * @param title The notification title
 * @param body The notification body
 * @param data Optional data payload
 * @returns Promise that resolves with the response
 */
async function sendFCMMessageToTopic(
  serviceAccountPath: string,
  projectId: string,
  topic: string,
  data?: Record<string, string>
): Promise<any> {
  const url = `https://fcm.googleapis.com/v1/projects/${projectId}/messages:send`;
  
  // Get access token from service account
  const accessToken = await getAccessToken(serviceAccountPath);
  
  const message = {
    message: {
      topic,
      data,
    }
  };

  try {
    const response = await axios.post(
      url,
      message,
      {
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${accessToken}`
        }
      }
    );
    console.log('Successfully sent message to topic:', response.data);
    return response.data;
  } catch (error) {
    console.error('Error sending message to topic:', error);
    throw error;
  }
}

async function main() {
  const serviceAccountPath = '';
  const projectId = '';
  const topic = '';
  const data = { mail: '', number: '' };

  await sendFCMMessageToTopic(serviceAccountPath, projectId, topic, data);
  console.log('Message sent successfully');
}

main();