async function handleActivity(context: TurnContext) {

    updateChannelIdToAdapterMap(context);

    switch (context.activity.text.trim().toLowerCase()) {
        case 'help':
            return replyWithHelp(context);
        case 'subscribe':
            subscribeUser(context);
            return context.sendActivity('You have subscribed');
        default:
            context.sendActivity(`You said ${context.activity.text}`);

            let recognized = await model.recognize(context);
            let intentName = topIntent(recognized);
            switch (intentName) {
                case 'Reminder_Find':
                    return await replyWithReminders(context);
                case 'Reminder_Create':
                    return await createReminders(context, recognized);
                default:
                    return await replyWithHelp(context);
            }
    }
}

async function createReminders(context: TurnContext, recognized: RecognizerResult) {
    context.sendActivity('Create reminder ');
    let intent = topIntent(recognized);
    let score = intent ? recognized.intents[intent].score : 0;
    if (intent) {
        await context.sendActivity(`Score: ${score}, Intents: ${JSON.stringify(recognized.entities)}`).catch(e => { console.error(e); throw e })
    };
}

async function subscribeUser(context: TurnContext) {
    const activity = context.activity;
    const conversationReference = TurnContext.getConversationReference(activity);
    const user = (conversationReference.user) ? conversationReference.user.id : undefined;
    if (!user) {
        throw new Error('No user in subscribe');
    }

    let adapter = context.adapter;
    await saveToConversationsStore(user, conversationReference);

    setTimeout(() => {
        messageUser(adapter, user, "You've been notified");
    }, 4000);
}

function replyWithHelp(context: TurnContext) {
    return context.sendActivity('You can subscribe, create, or find reminders.');
}

function updateChannelIdToAdapterMap(context: TurnContext) {
    // Not need here since we do the hack below to record the adapter.  Also this won't work with multiple BotFrameworkAdapters.
    let channelId = (context.activity && context.adapter) ? TurnContext.getConversationReference(context.activity).channelId : undefined;
    if (channelId) adapters[channelId] = context.adapter;
}

async function replyWithReminders(context: TurnContext) {
    await context.sendActivity('Reminders...').catch(e => { console.error(e); throw e })
}