Treasure hunt

function treasureHunt(input) {
  let initialChest = input.shift().split("|");
  let commandLine = input.shift();

  while (commandLine !== "Yohoho!") {
    if (commandLine.includes("Loot")) {
      let array = commandLine.split(" ");
      let command = array.shift();
      let loot = array.shift();
      while (loot !== undefined) {
        if (!initialChest.includes(loot)) {
          initialChest.unshift(loot);
        }
        loot = array.shift();
      }
    } else if (commandLine.includes("Drop")) {
      let [command, index] = commandLine.split(" ");
      index = Number(index);
      if (index > -1 && index < initialChest.length) {
        initialChest.push(initialChest[index]);
        initialChest.splice(index, 1);
      }
    } else if (commandLine.includes("Steal")) {
      let [command, count] = commandLine.split(" ");
      count = Number(count);
      if (count > initialChest.lenght) {
        console.log(initialChest.join(', '));
        initialChest = [];
      } else {
        let stolen = initialChest.splice(initialChest.length - count);
        console.log(stolen.join(", "));
      }
    }
    commandLine = input.shift();
  }

  let lengthSum = 0;
  let count = 0;
  initialChest.forEach((element) => {
    lengthSum += element.length;
    count++;
  });

  let averageGain = lengthSum / count;

  if (initialChest.length === 0) {
    console.log(`Failed treasure hunt.`);
  } else {
    console.log(
      `Average treasure gain: ${averageGain.toFixed(2)} pirate credits.`
    );
  }
}