import { describe, expect, it } from 'vitest';
import type { Dir } from '@two-keys/shared';
import {
  continueDefuse,
  defuseAction,
  generateDevice,
  isSolvable,
  remainingAt,
  solveButton,
  solveKeypad,
  solveWires,
  tickDefuse,
  timerText,
  type DefuseState,
} from '../src/engines/defuse';
import { DELTAS, cellAt, findCells, moveExplorer, type LabyrinthState } from '../src/engines/labyrinth';
import { answerSync, continueSync, type SyncState } from '../src/engines/sync';
import { clock, defuse, labyrinth, playingRoom, sync } from './helpers';

describe('defuse solver', () => {
  const game = defuse();

  it.each(game.fixtures.wires)('wires fixture %#', (f) => {
    expect(solveWires(f.serial, f.wires)).toEqual(f.expect);
  });
  it.each(game.fixtures.button)('button fixture %#', (f) => {
    expect(solveButton(f)).toEqual(f.expect);
  });
  it.each(game.fixtures.keypad)('keypad fixture %#', (f) => {
    expect(solveKeypad(f.symbols, game.modules.keypad.columns)).toEqual(f.expect);
  });

  it('never generates a device the solver cannot solve', () => {
    for (let seed = 1; seed <= 2000; seed++) {
      const device = generateDevice(game, 2, seed);
      expect(isSolvable(game, device), `seed ${seed}`).toBe(true);
      expect(device.serial).toMatch(/^[A-Z0-9]{5}\d$/);
      expect(device.wires!.colors.length).toBeGreaterThanOrEqual(3);
      expect(device.wires!.colors.length).toBeLessThanOrEqual(5);
      expect(device.keypad!.symbols).toHaveLength(4);
    }
  });

  it('is deterministic per seed and only builds the modules of the level', () => {
    expect(generateDevice(game, 2, 42)).toEqual(generateDevice(game, 2, 42));
    const lvl1 = generateDevice(game, 0, 42);
    expect(lvl1.wires).toBeDefined();
    expect(lvl1.button).toBeUndefined();
    expect(lvl1.keypad).toBeUndefined();
  });

  it('formats the timer like the device shows it', () => {
    expect(timerText(180)).toBe('3:00');
    expect(timerText(64.2)).toBe('1:05');
    expect(timerText(-3)).toBe('0:00');
  });
});

describe('defuse level flow', () => {
  const game = defuse();

  /** Solves whatever is on the device, using only the solver. */
  function solveAll(room: ReturnType<typeof playingRoom>, t: ReturnType<typeof clock>) {
    const s = room.engine as DefuseState;
    const d = s.device!;
    if (d.wires) defuseAction(game, t.ctx(100), 'A', 'wires', solveWires(d.serial, d.wires.colors));
    if (d.keypad) {
      for (const symbol of solveKeypad(d.keypad.symbols, game.modules.keypad.columns)!) {
        defuseAction(game, t.ctx(100), 'A', 'keypad', { type: 'press', symbol });
      }
    }
    if (d.button) {
      const solution = solveButton({ ...d.button, batteries: d.batteries });
      if (solution.type === 'tap') {
        defuseAction(game, t.ctx(100), 'A', 'button', { type: 'tap' });
      } else {
        defuseAction(game, t.ctx(100), 'A', 'button', { type: 'hold' });
        // Wait until the server's own timer shows the digit, then let go.
        for (let i = 0; i < 400; i++) {
          if (timerText(remainingAt(s, t.now)).includes(String(solution.releaseDigit))) break;
          t.ctx(500);
        }
        defuseAction(game, t.ctx(0), 'A', 'button', { type: 'release' });
      }
    }
  }

  it('clears all three levels for a key each and finishes the game', () => {
    const room = playingRoom(game);
    const t = clock(room);
    for (let level = 0; level < game.levels.length; level++) {
      expect(continueDefuse(game, t.ctx()).ok).toBe(true); // start
      solveAll(room, t);
      const s = room.engine as DefuseState;
      expect(s.strikes, `level ${level}`).toBe(0);
      expect(s.status).toBe('cleared');
      if (level < game.levels.length - 1) continueDefuse(game, t.ctx());
    }
    expect(room.keys).toEqual(game.levels.map((l) => l.keyName));
    expect(room.phase).toBe('finished');
    expect(room.result?.success).toBe(true);
  });

  it('strikes speed the clock up by 25% and three strikes blow the level without losing keys', () => {
    const room = playingRoom(game);
    room.keys.push('Earlier Key');
    const t = clock(room);
    continueDefuse(game, t.ctx());
    const s = room.engine as DefuseState;
    const right = solveWires(s.device!.serial, s.device!.wires!.colors).index;
    const wrong = right === 1 ? 2 : 1;

    defuseAction(game, t.ctx(), 'A', 'wires', { type: 'cut', index: wrong });
    expect(s.strikes).toBe(1);
    expect(s.clock!.speed).toBeCloseTo(1.25);
    const before = remainingAt(s, t.now);
    expect(before - remainingAt(s, t.now + 4000)).toBeCloseTo(5);

    expect(defuseAction(game, t.ctx(), 'B', 'wires', { type: 'cut', index: right }).ok).toBe(false); // Expert can't cut
    defuseAction(game, t.ctx(), 'A', 'wires', { type: 'cut', index: wrong });
    defuseAction(game, t.ctx(), 'A', 'wires', { type: 'cut', index: wrong });
    expect(s.status).toBe('exploded');
    expect(s.failReason).toBe('strikes');
    expect(room.keys).toEqual(['Earlier Key']);

    const oldSeed = s.seed;
    continueDefuse(game, t.ctx()); // retry → briefing with a new seed
    expect(s).toMatchObject({ status: 'ready', level: 0, strikes: 0, device: null });
    expect(s.seed).not.toBe(oldSeed);
  });

  it('explodes when the clock runs out', () => {
    const room = playingRoom(game);
    const t = clock(room);
    continueDefuse(game, t.ctx());
    expect(tickDefuse(t.ctx(10_000))).toBe(false);
    expect(tickDefuse(t.ctx(game.levels[0].timeSeconds * 1000))).toBe(true);
    expect(room.engine).toMatchObject({ status: 'exploded', failReason: 'time' });
  });
});

describe('sync', () => {
  const game = sync();

  it('awards a key for 3+ matches, offers one replay otherwise, and never repeats a question', () => {
    const room = playingRoom(game);
    const t = clock(room);
    const s = room.engine as SyncState;
    const seen: string[] = [];

    const playRound = (matches: number) => {
      for (let i = 0; i < game.rules.questionsPerRound; i++) {
        const q = s.questions[s.q];
        seen.push(q.id);
        expect(answerSync(game, t.ctx(), 'A', q.id, 0).ok).toBe(true);
        expect(answerSync(game, t.ctx(), 'A', q.id, 1).ok).toBe(false); // locked in
        expect(continueSync(game, t.ctx()).ok).toBe(false); // partner still thinking
        expect(answerSync(game, t.ctx(), 'B', q.id, i < matches ? 0 : 1).ok).toBe(true);
        expect(s.status).toBe('reveal');
        continueSync(game, t.ctx());
      }
      expect(s.status).toBe('summary');
    };

    continueSync(game, t.ctx()); // intro → first question
    playRound(2); // fail
    expect(s.earned).toBe(false);
    continueSync(game, t.ctx()); // replay with fresh questions
    expect(s).toMatchObject({ round: 0, attempt: 1, status: 'question' });
    playRound(1); // fail again: no more replays
    continueSync(game, t.ctx());
    expect(s).toMatchObject({ round: 1, attempt: 0, status: 'intro' });

    continueSync(game, t.ctx());
    playRound(3);
    expect(room.keys).toEqual([game.rounds[1].keyName]);
    continueSync(game, t.ctx()); // earned → straight to round 3
    expect(s.round).toBe(2);

    continueSync(game, t.ctx());
    playRound(5);
    continueSync(game, t.ctx());
    expect(room.phase).toBe('finished');
    expect(room.keys).toHaveLength(2);
    expect(new Set(seen).size).toBe(seen.length);
  });
});

describe('labyrinth', () => {
  const game = labyrinth();
  const walk = (room: ReturnType<typeof playingRoom>, t: ReturnType<typeof clock>, path: string) =>
    [...path].map((dir) => moveExplorer(game, t.ctx(), 'B', dir as Dir));

  it('validates every move on the server', () => {
    const room = playingRoom(game);
    const t = clock(room);
    const s = room.engine as LabyrinthState;
    expect(s).toMatchObject({ x: 1, y: 1 });
    expect(moveExplorer(game, t.ctx(), 'B', 'n')).toMatchObject({ ok: false, code: 'wall' });
    expect(moveExplorer(game, t.ctx(), 'A', 'e')).toMatchObject({ ok: false, code: 'wrong_role' });
    expect(s).toMatchObject({ x: 1, y: 1, moves: 0 });
    expect(moveExplorer(game, t.ctx(), 'B', 'e').ok).toBe(true);
    expect(s).toMatchObject({ x: 2, y: 1, moves: 1 });
  });

  it('sends the Explorer back to the start on a trap, with a penalty, keys kept', () => {
    const room = playingRoom(game);
    const t = clock(room);
    const s = room.engine as LabyrinthState;
    walk(room, t, 'ssss'); // (1,5)
    walk(room, t, 'ee'); // (3,5)
    const ctx = t.ctx();
    moveExplorer(game, ctx, 'B', 'e'); // (4,5) is a trap
    expect(s).toMatchObject({ x: 1, y: 1, falls: 1 });
    expect(room.penaltySeconds).toBe(60);
    expect(ctx.toasts).toEqual([{ to: 'A', message: expect.stringMatching(/fell into a trap/) }]);
  });

  it('can be completed: three lanterns, then the exit', () => {
    const room = playingRoom(game);
    const t = clock(room);
    const s = room.engine as LabyrinthState;

    // Breadth-first route planner over safe cells, standing in for a good Navigator.
    const goTo = (target: { x: number; y: number }) => {
      const start = `${s.x},${s.y}`;
      const prev = new Map<string, { from: string; dir: Dir }>();
      const queue = [{ x: s.x, y: s.y }];
      const seen = new Set([start]);
      while (queue.length) {
        const p = queue.shift()!;
        for (const dir of Object.keys(DELTAS) as Dir[]) {
          const n = { x: p.x + DELTAS[dir].x, y: p.y + DELTAS[dir].y };
          const c = cellAt(game.grid, n.x, n.y);
          if (c === '#' || c === 'T' || seen.has(`${n.x},${n.y}`)) continue;
          seen.add(`${n.x},${n.y}`);
          prev.set(`${n.x},${n.y}`, { from: `${p.x},${p.y}`, dir });
          queue.push(n);
        }
      }
      const path: Dir[] = [];
      for (let at = `${target.x},${target.y}`; at !== start; at = prev.get(at)!.from) path.unshift(prev.get(at)!.dir);
      for (const dir of path) expect(moveExplorer(game, t.ctx(), 'B', dir).ok).toBe(true);
    };

    const [exit] = findCells(game.grid, 'E');
    goTo(exit);
    expect(room.phase).toBe('playing'); // locked without lanterns
    expect(s.message).toBe(game.explorerView.flavour.exitLocked);

    for (const lantern of game.lanterns) goTo(lantern);
    expect(room.keys).toEqual(expect.arrayContaining(game.lanterns.map((l) => l.name)));
    goTo(exit);
    expect(room.phase).toBe('finished');
    expect(s.falls).toBe(0);
  });
});