import assert from 'node:assert/strict';
import { test } from 'node:test';
import { Board } from '../src/board';
import { Game } from '../src/game';
import { PointerInput } from '../src/input';
import type { CellDef } from '../src/types';

const c = (id: string, x: number, y: number, w = 1, h = 1, clue?: number): CellDef => ({ id, x, y, w, h, clue });

// 一横四格：a(1) b c d
function setup() {
  const b = Board.fromCells([c('a', 0, 0, 1, 1, 1), c('b', 1, 0), c('c', 2, 0), c('d', 3, 0)]);
  const g = new Game(b);
  return { b, g, input: new PointerInput(g) };
}

test('按下起点后滑动追加；滑回上一格撤销；松手保留路径', () => {
  const { g, input } = setup();
  input.down(0);
  assert.equal(g.path.length, 1);
  input.move(1);
  input.move(2);
  assert.deepEqual([...g.path], [0, 1, 2]);
  input.move(1); // 滑回上一格 = 撤销
  assert.deepEqual([...g.path], [0, 1]);
  input.up();
  assert.equal(g.status, 'idle');
  assert.deepEqual([...g.path], [0, 1]);
});

test('松手后从末端按下可继续；按不相邻的空格不生效', () => {
  const { g, input } = setup();
  input.down(0);
  input.move(1);
  input.up();
  input.down(3); // 不相邻的空格
  assert.equal(input.isDrawing, false);
  input.move(2);
  assert.equal(g.path.length, 2);
  input.up();
  input.down(1); // 末端
  assert.equal(input.isDrawing, true);
  input.move(2);
  assert.deepEqual([...g.path], [0, 1, 2]);
});

test('点末端的前一格 = 撤销一步，且可以接着滑', () => {
  const { g, input } = setup();
  input.down(0);
  input.move(1);
  input.move(2);
  input.up();
  input.down(1);
  assert.deepEqual([...g.path], [0, 1]);
  assert.equal(input.isDrawing, true);
  input.move(0);
  assert.deepEqual([...g.path], [0]);
});

test('点末端旁边的空格直接追加（点着走）', () => {
  const { g, input } = setup();
  input.down(0);
  input.up();
  input.down(1);
  assert.deepEqual([...g.path], [0, 1]);
});

test('有线索 1 时点别的格起手无效并产生 rejectStart', () => {
  const { g, input } = setup();
  const ev = input.down(2);
  assert.equal(ev[0].type, 'rejectStart');
  assert.equal(g.path.length, 0);
  assert.equal(input.isDrawing, false);
  assert.deepEqual(input.move(1), []);
});

test('滑到不相邻格忽略；空白 -1 不影响；同一格不重复触发', () => {
  const { g, input } = setup();
  input.down(0);
  input.move(-1);
  input.move(2); // 不相邻
  assert.deepEqual([...g.path], [0]);
  input.move(1);
  input.move(1);
  assert.deepEqual([...g.path], [0, 1]);
});

test('过关后停止响应', () => {
  const { g, input } = setup();
  input.down(0);
  input.move(1);
  input.move(2);
  const ev = input.move(3);
  assert.ok(ev.some((e) => e.type === 'cleared'));
  assert.equal(input.isDrawing, false);
  assert.deepEqual(input.down(3), []);
  assert.deepEqual(input.move(2), []);
  assert.equal(g.path.length, 4);
});

test('点更早的历史格一次撤掉多步，不松手即可沿新分支继续', () => {
  const b = Board.fromCells([
    c('a', 0, 0, 1, 1, 1), c('b', 1, 0), c('c', 2, 0),
    c('d', 2, 1), c('e', 1, 1), c('f', 0, 1),
  ]);
  const g = new Game(b);
  const input = new PointerInput(g);
  input.down(0);
  [1, 2, 3, 4].forEach(cell => input.move(cell));
  input.up();
  const events = input.down(1);
  assert.deepEqual(g.path, [0, 1]);
  assert.deepEqual(events, [
    { type: 'unstep', cell: 4, step: 5 },
    { type: 'unstep', cell: 3, step: 4 },
    { type: 'unstep', cell: 2, step: 3 },
    { type: 'rewound', cell: 1, removed: 3 },
  ]);
  assert.equal(input.isDrawing, true);
  assert.equal(g.status, 'drawing');
  input.move(4); // 从第 2 格直接转入之前的第 5 格
  input.move(5);
  input.up();
  assert.deepEqual(g.path, [0, 1, 4, 5]);
  assert.equal(g.stepOf(4), 3);
  assert.equal(g.stepOf(2), 0);
  assert.equal(g.status, 'idle');
});

test('不松手滑到不相邻历史格可直接回退；同格抖动不会重复撤销', () => {
  const { g, input } = setup();
  input.down(0);
  input.move(1);
  input.move(2);
  input.move(0); // 与末端不相邻，仍能一次回到起点
  assert.deepEqual(g.path, [0]);
  assert.deepEqual(input.move(0), []);
  input.move(1);
  assert.deepEqual(g.path, [0, 1]);
});