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

type tile = { guard: boolean; blocked: boolean; visited: boolean };

const test = true;

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

let timer = now.instant();
console.log(
  "part one:",
  (() => {
    let floor = data
      .split("\n")
      .slice(0, -1)
      .reduce((floor, row, i) => {
        row.split("").forEach((v, col) => {
          floor[`${i}|${col}`] = {
            guard: v === "^",
            blocked: v === "#",
            visited: false,
          };
        });
        return floor;
      }, {} as Record<string, tile>);

    let direction = "north";
    let [guard] = Object.entries(floor).filter((tile) => tile[1].guard)[0];
    while (true) {
      let [x, y] = guard.split("|").map((v) => parseInt(v, 10));
      floor[guard].visited = true;
      let next = "";
      switch (direction) {
        case "north":
          next = `${x - 1}|${y}`;
          break;
        case "south":
          next = `${x + 1}|${y}`;
          break;
        case "east":
          next = `${x}|${y + 1}`;
          break;
        case "west":
          next = `${x}|${y - 1}`;
          break;
      }
      if (floor[next] === undefined) {
        break;
      }
      if (!floor[next].blocked) {
        floor[next].guard = true;
        floor[guard].guard = false;
        guard = next;
      } else {
        if (direction === "north") {
          direction = "east";
        } else if (direction === "east") {
          direction = "south";
        } else if (direction === "south") {
          direction = "west";
        } else if (direction === "west") {
          direction = "north";
        }
      }
    }
    return Object.entries(floor).reduce((total, tile) => {
      return total + (tile[1].visited ? 1 : 0);
    }, 0);
  })(),
  printTime(now.instant().since(timer))
);