// Module 8: Push chains. Each test matches a heading in scenarios.md.
import { expect, test } from "vitest";
import { newBaba, type Baba } from "../src/harness";

/** An empty level `width` wide and `height` high. */
const emptyLevel = (width: number, height: number) => ({ width, height, objects: [] });

/** Place one text object per word: `[word, x, y]`. */
function write(b: Baba, words: [string, number, number][]): void {
  for (const [word, x, y] of words) b.place(`text:${word}`, x, y);
}

test("test_08_chain_moves_together", () => {
  const b = newBaba(emptyLevel(6, 4));
  write(b, [
    ["BABA", 0, 0],
    ["IS", 1, 0],
    ["YOU", 2, 0],
  ]);
  write(b, [
    ["ROCK", 0, 1],
    ["IS", 1, 1],
    ["PUSH", 2, 1],
  ]);
  const baba = b.place("baba", 0, 3);
  const rocks = [b.place("rock", 1, 3), b.place("rock", 2, 3), b.place("rock", 3, 3)];

  b.move("right");

  expect(b.posOf(baba)).toEqual([1, 3]);
  expect(b.posOf(rocks[0])).toEqual([2, 3]);
  expect(b.posOf(rocks[1])).toEqual([3, 3]);
  expect(b.posOf(rocks[2])).toEqual([4, 3]);
  expect(b.kindsAt(0, 3)).toEqual([]);
  expect(b.kindsAt(4, 3)).toEqual(["rock"]);
});

test("test_08_chain_into_stop_nothing_moves", () => {
  const b = newBaba(emptyLevel(6, 5));
  write(b, [
    ["BABA", 0, 0],
    ["IS", 1, 0],
    ["YOU", 2, 0],
  ]);
  write(b, [
    ["ROCK", 0, 1],
    ["IS", 1, 1],
    ["PUSH", 2, 1],
  ]);
  write(b, [
    ["WALL", 0, 2],
    ["IS", 1, 2],
    ["STOP", 2, 2],
  ]);
  const baba = b.place("baba", 0, 4);
  const rocks = [b.place("rock", 1, 4), b.place("rock", 2, 4), b.place("rock", 3, 4)];
  const wall = b.place("wall", 4, 4);

  b.move("right");

  expect(b.posOf(baba)).toEqual([0, 4]);
  expect(b.posOf(rocks[0])).toEqual([1, 4]);
  expect(b.posOf(rocks[1])).toEqual([2, 4]);
  expect(b.posOf(rocks[2])).toEqual([3, 4]);
  expect(b.posOf(wall)).toEqual([4, 4]);
});

test("test_08_open_shut_during_push", () => {
  const b = newBaba(emptyLevel(5, 5));
  write(b, [
    ["BABA", 0, 0],
    ["IS", 1, 0],
    ["YOU", 2, 0],
  ]);
  write(b, [
    ["KEY", 0, 1],
    ["IS", 1, 1],
    ["PUSH", 2, 1],
    ["AND", 3, 1],
    ["OPEN", 4, 1],
  ]);
  write(b, [
    ["DOOR", 0, 2],
    ["IS", 1, 2],
    ["STOP", 2, 2],
    ["AND", 3, 2],
    ["SHUT", 4, 2],
  ]);
  const baba = b.place("baba", 0, 4);
  const key = b.place("key", 1, 4);
  const door = b.place("door", 2, 4);

  b.move("right");

  expect(b.posOf(key)).toBeNull();
  expect(b.posOf(door)).toBeNull();
  // Inferred, not stated by a source: Baba lands on the key's former tile.
  expect(b.posOf(baba)).toEqual([1, 4]);
  expect(b.kindsAt(2, 4)).toEqual([]);
  expect(b.kindsAt(1, 4)).toEqual(["baba"]);
});

test("test_08_text_pushed", () => {
  const b = newBaba(emptyLevel(4, 5));
  write(b, [
    ["BABA", 0, 0],
    ["IS", 1, 0],
    ["YOU", 2, 0],
  ]);
  const baba = b.place("baba", 0, 2);
  const rockText = b.place("text:ROCK", 1, 2);
  write(b, [
    ["IS", 2, 3],
    ["PUSH", 2, 4],
  ]);

  expect(b.rules()).toEqual(["BABA IS YOU", "TEXT IS PUSH"]);

  b.move("right");

  expect(b.posOf(baba)).toEqual([1, 2]);
  expect(b.posOf(rockText)).toEqual([2, 2]);
  expect(b.rules()).toEqual(["BABA IS YOU", "ROCK IS PUSH", "TEXT IS PUSH"]);
});

test("test_08_level_edge_is_stop", () => {
  const b = newBaba(emptyLevel(3, 3));
  write(b, [
    ["BABA", 0, 0],
    ["IS", 1, 0],
    ["YOU", 2, 0],
  ]);
  const baba = b.place("baba", 1, 2);
  const flagText = b.place("text:FLAG", 2, 2);

  b.move("right");

  expect(b.posOf(baba)).toEqual([1, 2]);
  expect(b.posOf(flagText)).toEqual([2, 2]);

  b.move("down");

  expect(b.posOf(baba)).toEqual([1, 2]);
  expect(b.posOf(flagText)).toEqual([2, 2]);
});