Automated apartment complex buzzer entry

twilio_buzzer_call.js

// DIY version of e.g. https://lowkeybuzzer.com

const axios = require("axios");

exports.handler = async function(context, event, callback) {
  const twiml = new Twilio.twiml.VoiceResponse();

  const logWebhookUrl = context.DISCORD_WEBHOOK_LOGS || "";

  const doGrantAccess = ["", "true", "1", "yes"].includes((context.DO_GRANT_ACCESS || "").toLowerCase()); // default true
  const doForward = ["", "true", "1", "yes"].includes((context.DO_FORWARD_CALLS || "").toLowerCase());  // default true

  const buzzerNumber = context.BUZZER_PHONE_NUMBER || "";
  const forwardNumber = context.PERSONAL_PHONE_NUMBER || "";
  if (buzzerNumber === "") {
    console.warn("BUZZER_PHONE_NUMBER environment variable is not set");
  }
  if (forwardNumber === "") {
    console.warn("PERSONAL_PHONE_NUMBER environment variable is not set");
  }

  const digitsAccept = context.DIGITS_ACCEPT || "9";
  const digitsAcceptExtra = context.DIGITS_ACCEPT_EXTRA || "";
  const pauseSecsBefore = Number(context.PAUSE_SECONDS_BEFORE) || 7;
  const pauseSecsExtraBefore = Number(context.PAUSE_SECONDS_EXTRA_BEFORE) || 3;
  const pauseSecsAfter = Number(context.PAUSE_SECONDS_AFTER) || 3;

  const log = async (msg) => {
    console.log(msg);

    if (logWebhookUrl === "") {
      return;
    }
    try {
      await axios.post(logWebhookUrl, { content: msg });
    } catch (err) {
      console.error(`Error sending log to Discord: ${err}`);
    }
  };

  // Handle buzzer call
  if (event.From === buzzerNumber) {
    // Grant access
    if (doGrantAccess) {
      await log(`Receiving call from ${event.From}. Detected as buzzer call. Granting access.`);
      twiml.pause({ length: pauseSecsBefore });
      twiml.play({ digits: digitsAccept });
      if (digitsAcceptExtra !== "") {
        twiml.pause({ length: pauseSecsExtraBefore });
        twiml.play({ digits: digitsAcceptExtra });
      }
    } else {
      await log(`Receiving call from ${event.From}. Detected as buzzer call. Denying access.`);
    }
    twiml.pause({ length: pauseSecsAfter });
  } else {
    // Forward everything else, e.g. for phone number verification
    if (!doForward) {
      await log(`Receiving call from ${event.From}. Detected as normal call. Won't forward since call forwarding is disabled.`);
    } else if (forwardNumber === "") {
      await log(`Receiving call from ${event.From}. Detected as normal call. Won't forward since forward number not configured.`);
    } else {
      await log(`Receiving call from ${event.From}. Detected as normal call. Forwarding to ${forwardNumber}.`);
      twiml.dial(forwardNumber);
    }
  }

  callback(null, twiml);
};

twilio_buzzer_sms.js

const axios = require("axios");

exports.handler = async function(context, event, callback) {
  // NOTE: requires the "axios" NPM package added to the Twilio Service's dependencies

  // NOTE: proactive SMS messaging requires registering as a sole proprietor
  // REF: https://www.twilio.com/docs/messaging/compliance/a2p-10dlc/direct-sole-proprietor-registration-overview
  // REF: https://console.twilio.com/us1/develop/sms/regulatory-compliance/a2p-10dlc-overview

  const twiml = new Twilio.twiml.MessagingResponse();

  const logWebhookUrl = context.DISCORD_WEBHOOK_LOGS || "";

  const doForwardSMS = ["", "true", "1", "yes"].includes((context.DO_FORWARD_SMS || "").toLowerCase());  // default true
  const doForwardDiscord = ["", "true", "1", "yes"].includes((context.DO_FORWARD_DISCORD || "").toLowerCase());  // default true

  const forwardSMSNumber = doForwardSMS ? (context.PERSONAL_PHONE_NUMBER || "") : "";
  const forwardDiscordURL = doForwardDiscord ? (context.DISCORD_WEBHOOK_SMS || "") : "";
  const doForward = (forwardSMSNumber !== "") || (forwardDiscordURL !== "");

  const log = async (msg) => {
    console.log(msg);

    if (logWebhookUrl === "") {
      return;
    }
    try {
      await axios.post(logWebhookUrl, { content: msg });
    } catch (err) {
      console.error(`Error sending log to Discord: ${err}`);
    }
  };

  // Forward everything, e.g. for phone number verification
  if (!doForward) {
    await log(`Receiving SMS from ${event.From}. Won't forward since no forward configured.`);
  }
  if (forwardSMSNumber !== "") {
    await log(`Receiving SMS from ${event.From}. Forwarding via SMS to ${forwardSMSNumber}.`);
    const msg = `New text from ${event.From}:\n\n${event.Body}`;
    twiml.message({ to: forwardSMSNumber }, msg);
  }
  if (forwardDiscordURL !== "") {
    await log(`Receiving SMS from ${event.From}. Forwarding via Discord to configured SMS webhook.`);
    const msg = `New text from **${event.From}**\n>>> ${event.Body}`
    try {
      await axios.post(forwardDiscordURL, { content: msg });
    } catch (err) {
      console.error(`Error forwarding SMS to Discord: ${err}`);
    }
  }

  callback(null, twiml);
};