import * as R from "remeda";

export const comsys = () => {
  let cycle = 0;
  let register = 1;
  const scheduled = [];

  return (instr) => {
    if (instr && instr[0] === "addx") {
      scheduled.push(0, instr[1]);
    } else if (instr) {
      scheduled.push(0);
    }
    cycle++;
    register += scheduled.shift() ?? 0;
    return { cycle, register };
  };
};

const toPixel = (entry, i) => {
  if (entry.register >= i - 1 && entry.register <= i + 1) return "#";
  else return ".";
};

export default (instructions) => {
  const sys = comsys();

  instructions = [...instructions];
  return R.pipe(
    [sys(), ...R.range(0, 239).map(() => sys(instructions.shift()))],
    R.chunk(40),
    R.map((line) => line.map(toPixel).join("") + "\n"),
    (lines) => lines.join("")
  );
};