Advent of Code 2023 - Day 20 - Parser

const LOW_PULSE = "low";
const HIGH_PULSE = "high";

const parse = (input) => {
  const lines = utils.getInputLines(input);
  const modules = {};
  const inputMap = {};
  const rxInputs = [];
  for (let line of lines) {
    const parts = line.split("->");
    const label = parts[0].trim() == "broadcaster" ? "broadcaster" : parts[0].trim().substring(1);
    const type = parts[0].trim().charAt(0);
    const destinations = parts[1].trim().split(", ");
    if (destinations.includes("rx")) {
      rxInputs.push(label);
    }
    for (const d of destinations) {
      if (!inputMap[d]) {
        inputMap[d] = [];
      }
      inputMap[d].push(label);
    }
    modules[label] = {
      label: label,
      type: type,
      destinations: destinations,
    };
    if (type == "%") {
      modules[label].on = false;
    }
  }
  for (const label of Object.keys(inputMap)) {
    const module = modules[label];
    if (module?.type == "&") {
      module.inputs = inputMap[label].reduce((o, label) => {
        o[label] = LOW_PULSE;
        return o;
      }, {});
    }
  }
  return {
    modules: modules,
    rxInputs: rxInputs,
  };
};