import fs from "node:fs";
import { printTime, now, toNum } from "../util";

const test = false;

type coord = { x: bigint; y: bigint };

const data = fs.readFileSync(
  test ? "./inputs/testinput" : "./inputs/input",
  "utf8"
);

let timer = now.instant();
console.log(
  "part one:",
  data
    .split("\n")
    .slice(0, -1)
    .reduce((machines, curr, index) => {
      // parse this mess
      const machine = Math.floor(index / 4);
      switch (index % 4) {
        case 0:
          machines[machine] = {
            ...machines[machine],
            A: { x: BigInt(curr.slice(11, 14)), y: BigInt(curr.slice(17)) },
          };
          break;
        case 1:
          machines[machine] = {
            ...machines[machine],
            B: { x: BigInt(curr.slice(11, 14)), y: BigInt(curr.slice(17)) },
          };
          break;
        case 2:
          let coords = curr.slice(9).split(", ");
          machines[machine] = {
            ...machines[machine],
            Prize: { x: BigInt(coords[0]), y: BigInt(coords[1].slice(2)) },
          };
        // skip processing the blank line
      }
      return machines;
    }, [] as Array<{ A: coord; B: coord; Prize: coord }>)
    .filter((machine) => {
      // remove machines where it's impossible to reach the prize within 100 presses of each button
      return !(
        machine.A.x * BigInt(100) + machine.B.x * BigInt(100) <
          machine.Prize.x ||
        machine.A.y * BigInt(100) + machine.B.y * BigInt(100) < machine.Prize.y
      );
    })
    .map((m) => {
      //94a/22 - 34a/67 = 8400/22 - 5400/67
      for (let a = BigInt(0); a < 101; a++) {
        if (
          (m.A.x * a) / m.B.x - (m.A.y * a) / m.B.y ==
          m.Prize.x / m.B.x - m.Prize.y / m.B.y
        ) {
          // b = 8400/22 - 94(a)/22
          return a * BigInt(3) + m.Prize.x / m.B.x - (m.A.x * a) / m.B.x;
        }
      }
    })
    .reduce((total: bigint, m) => {
      if (m !== undefined) {
        return total + m;
      }
      return total;
    }, BigInt(0)),
  printTime(now.instant().since(timer))
);

// timer = now.instant();
// console.log(
//   "part two:",
//   data.split("\n").slice(0, -1),
//   printTime(now.instant().since(timer))
// );