contactRelationUpdate event hook to persist data to firebase

contactRelationUpdate.js

bot.on("contactRelationUpdate", (message) => {

    const userId = message.user.id;
    const username = message.user.name || "--";
    const channelId = message.address.channelId;
    const address = message.address;

    // When the users adds the bot
    if (message.action === "add") {
        // Persist the user to firebase
        // Create a reference for the specific channel and user e.g. `emulator/userA` or `slack/userA` or `skype/userB`
        firebase.database().ref(`chat-users/${channelId}/${userId}`)
            .set({
                userId, username, channelId, address, // Data stored in firebase
            })
            .then(() => {
                // Once we've stored this simply reply to the user welcoming them
                bot.send(new builder.Message()
                    .address(message.address)
                    .text("Hello %s... Thanks for adding the bot", username));
            })
            .catch((err) => console.log(err));
    }

    // When a user removes the bot
    if (message.action === "remove") {

        // Remove the user from firebase (optional)
        firebase.database().ref(`chat-users/${channelId}/${userId}`)
            .remove()
            .then(() => {
                // Once removed send them a good bye message
                bot.send(new builder.Message()
                    .address(message.address)
                    .text("%s has removed the bot", username));
            })
            .catch((err) => console.log(err));
    }
});