portal/screen.ts

import { PrismaClient, Stanza } from "@prisma/client";
import LCD from "raspberrypi-liquid-crystal";
const prisma = new PrismaClient();

const TICK = 250;
const WAIT = 10;

const lcd = new LCD(1, 0x27, 16, 2);
lcd.beginSync();
lcd.clearSync();

const timer = (ms: number) => new Promise((res) => setTimeout(res, ms));
const getStanza = async () => {
  const stanzaCount = await prisma.stanza.count();
  const skip = Math.floor(Math.random() * stanzaCount);

  const randomStanza = await prisma.stanza.findMany({
    skip: skip,
    take: 1,
  });

  return randomStanza[0].text as string;
};

const tag =
  "                Black Portal 4856 E Davison, Detroit                                                                ";
let tagCharacterLocation = 0;
setInterval(() => {
  lcd.printLineSync(1, "                ");
  setTimeout(() => {
    lcd.printLineSync(
      1,
      tag.substring(tagCharacterLocation, 16 + tagCharacterLocation)
    );
  }, WAIT);

  tagCharacterLocation++;
  if (tagCharacterLocation > tag.length) {
    tagCharacterLocation = 0;
  }
}, TICK);

while (true) {
  let stanza = await getStanza();

  let stanzaOuterInterval;
  let stanzaInnerInterval;
  let stanzaCharacterLocation = 0;
  stanzaOuterInterval = setInterval(async () => {
    lcd.printLineSync(0, "                ");
    stanzaInnerInterval = setTimeout(() => {
      lcd.printLineSync(
        0,
        `${
          16 - stanzaCharacterLocation > 0
            ? Array(16 - stanzaCharacterLocation).join(" ")
            : ""
        }${stanza}`.substring(
          stanzaCharacterLocation,
          16 + stanzaCharacterLocation
        )
      );
    }, WAIT);
    stanzaCharacterLocation++;

    if (stanzaCharacterLocation > stanza.length) {
      stanza = await getStanza();
      stanzaCharacterLocation = 0;
    }
  }, TICK);

  await timer((16 + stanza.length) * (WAIT + TICK));
  clearInterval(stanzaOuterInterval);
  clearInterval(stanzaInnerInterval);
}