import assert from 'node:assert/strict';
import { test } from 'node:test';
import { Board } from '../src/board';
import { Game } from '../src/game';
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 });

// 1-3：start(1) a b(3) / d c
const level13 = () =>
  Board.fromCells([c('start', 0, 0, 1, 1, 1), c('a', 1, 0), c('b', 2, 0, 1, 1, 3), c('d', 1, 1), c('c', 2, 1)]);

test('有线索 1 时只能从它起手', () => {
  const g = new Game(level13());
  const ev = g.apply({ type: 'start', cell: 1 });
  assert.deepEqual(ev, [{ type: 'rejectStart', cell: 1, clueCell: 0 }]);
  assert.equal(g.status, 'empty');
  assert.equal(g.apply({ type: 'start', cell: 0 })[0].type, 'step');
  assert.equal(g.status, 'drawing');
});

test('无线索 1 时任意格可起手', () => {
  const g = new Game(Board.fromCells([c('a', 0, 0), c('b', 1, 0, 1, 1, 2)]));
  assert.equal(g.apply({ type: 'start', cell: 0 })[0].type, 'step');
});

test('追加只能到相邻未走格；冲突不打断；撤销恢复', () => {
  const b = level13();
  const g = new Game(b);
  const id = (s: string) => b.cellById(s).index;
  g.apply({ type: 'start', cell: id('start') });
  assert.deepEqual(g.apply({ type: 'append', cell: id('c') }), []); // 不相邻
  g.apply({ type: 'append', cell: id('a') });
  const ev = g.apply({ type: 'append', cell: id('d') }); // 第 3 步没落到预定的 b，立即冲突
  assert.equal(ev[0].type, 'step');
  assert.ok(ev.some(e => e.type === 'step' && e.conflict && !e.clueHit));
  assert.equal(g.isConflict(id('d')), true);
  assert.equal(g.stepOf(id('b')), 0, '无需先走到线索格，就能判断该步位置错误');
  g.apply({ type: 'append', cell: id('c') });
  const conflict = g.apply({ type: 'append', cell: id('b') });
  assert.equal(conflict[0].type, 'step');
  assert.equal((conflict[0] as { conflict: boolean }).conflict, true);
  assert.equal(g.isConflict(id('b')), true);
  assert.equal(g.path.length, 5);
  assert.equal(g.status, 'drawing', '填满但有冲突不算过关');
  // 走到头了但没过关 → deadEnd 事件
  assert.ok(conflict.some((e) => e.type === 'deadEnd'));
  const un = g.apply({ type: 'undo' });
  assert.deepEqual(un, [{ type: 'unstep', cell: id('b'), step: 5 }]);
  assert.equal(g.isConflict(id('b')), false);
  assert.equal(g.stepOf(id('b')), 0);
});

test('全走完且线索全对 → cleared，之后锁住', () => {
  const b = level13();
  const g = new Game(b);
  const id = (s: string) => b.cellById(s).index;
  for (const s of ['start', 'a', 'b', 'c']) g.apply(g.path.length ? { type: 'append', cell: id(s) } : { type: 'start', cell: id(s) });
  const ev = g.apply({ type: 'append', cell: id('d') });
  assert.ok(ev.some((e) => e.type === 'cleared'));
  assert.equal(g.status, 'cleared');
  assert.deepEqual(g.apply({ type: 'undo' }), []);
  assert.equal(g.path.length, 5);
});

test('release / resume / reset 状态流转', () => {
  const g = new Game(level13());
  g.apply({ type: 'start', cell: 0 });
  g.apply({ type: 'release' });
  assert.equal(g.status, 'idle');
  g.apply({ type: 'resume' });
  assert.equal(g.status, 'drawing');
  assert.deepEqual(g.apply({ type: 'reset' }), [{ type: 'reset' }]);
  assert.equal(g.status, 'empty');
  assert.equal(g.remaining, 5);
  assert.deepEqual(g.apply({ type: 'reset' }), [], '空盘重开不产生事件');
});

test('撤销到空盘回到 empty', () => {
  const g = new Game(level13());
  g.apply({ type: 'start', cell: 0 });
  g.apply({ type: 'undo' });
  assert.equal(g.status, 'empty');
  assert.equal(g.last, -1);
});

test('直接回退移除后缀冲突，保留前缀；非法目标、末端和过关后均忽略', () => {
  const g = new Game(level13());
  for (const cell of [0, 1, 3, 4, 2]) g.apply({ type: g.path.length ? 'append' : 'start', cell });
  assert.equal(g.hasConflict(), true);
  g.apply({ type: 'rewind', cell: 1 });
  assert.deepEqual(g.path, [0, 1]);
  assert.equal(g.hasConflict(), false);
  for (const cell of [-1, 4, 1]) assert.deepEqual(g.apply({ type: 'rewind', cell }), []);
  for (const cell of [2, 4, 3]) g.apply({ type: 'append', cell });
  assert.equal(g.isCleared, true);
  assert.deepEqual(g.apply({ type: 'rewind', cell: 0 }), []);
  assert.equal(g.path.length, 5);
});