import * as R from "remeda";

import { readFile } from "../05/part1.js";

function parseMonkey(block) {
  const re = new RegExp(
    `Starting items: (?<items>.+)
  Operation: new = (?<operation>.+)
  Test: divisible by (?<divisible>\\d+)
    If true: throw to monkey (?<ifTrue>\\d+)
    If false: throw to monkey (?<ifFalse>\\d+)`,
    "s"
  );

  const groups = { ...block.match(re).groups };

  ["divisible", "ifTrue", "ifFalse"].forEach(
    (k) => (groups[k] = parseInt(groups[k]))
  );

  groups.operation = eval("(old) => " + groups.operation);

  groups.items = groups.items.split(", ").map((x) => parseInt(x));

  return { ...groups, inspections: 0 };
}

const readInput = (...args) =>
  R.pipe(
    readFile(...args),
    (lines) => lines.split("\n\n"),
    R.compact, // remove last line
    R.map(parseMonkey)
  );

export const puzzleInput = readInput(import.meta.url, "input");
export const sample = readInput(import.meta.url, "sample");

const playTurn = (monkeys, monkey) => {
    monkey.inspections += monkey.items.length;

    monkey.items = monkey.items.map( i => monkey.operation(i) );

    monkey.items = monkey.items.map( i => Math.floor(i/3) );


    monkey.items.forEach( i => {
        monkeys[(i % monkey.divisible) ? monkey.ifFalse : monkey.ifTrue
        ].items.push(i)
    } )

    monkey.items = [];

    return;
};

const playRound = (monkeys) => {
    monkeys.forEach( monkey => playTurn(monkeys,monkey) );
    return monkeys;
}

export default R.createPipe(
    R.clone,
    (monkeys) => R.times(20, () => playRound(monkeys)),
    R.last(),
    R.map( R.prop('inspections') ),
    R.sortBy( R.identity ),
    R.reverse,
    R.take(2),
    R.reduce( (a,b) => a * b, 1 )
)