import { getLang, initLangToggle } from './i18n.js';

const CANVAS_W = 420;
const CANVAS_H = 520;
const PLAYER_Y = CANVAS_H - 40;
const PLAYER_W = 28;
const PLAYER_H = 14;
const PLAYER_SPEED = 220; // px/s
const BULLET_SPEED = 380;
const ENEMY_BULLET_SPEED = 180;
const FIRE_COOLDOWN_MS = 350;
const ENEMY_COLS = 8;
const ENEMY_ROWS = 4;
const ENEMY_W = 28;
const ENEMY_H = 18;
const ENEMY_GAP_X = 12;
const ENEMY_GAP_Y = 16;
const ENEMY_TOP = 50;
const ENEMY_STEP_DOWN = 18;

const STR = {
  ru: {
    hint: 'стрелки — двигать, пробел — огонь',
    score: 'счёт',
    lives: 'жизни',
    wave: 'волна',
    gameOver: 'ИГРА ОКОНЧЕНА',
    finalScore: (s) => `счёт: ${s}`,
    again: 'ещё раз',
    crosslinks: 'ещё игры:',
    fire: 'огонь',
  },
  en: {
    hint: 'arrows to move, space to fire',
    score: 'score',
    lives: 'lives',
    wave: 'wave',
    gameOver: 'GAME OVER',
    finalScore: (s) => `score: ${s}`,
    again: 'play again',
    crosslinks: 'more games:',
    fire: 'fire',
  },
};

function t() {
  return STR[getLang()];
}

function rectsOverlap(a, b) {
  return a.x < b.x + b.w && a.x + a.w > b.x && a.y < b.y + b.h && a.y + a.h > b.y;
}

class InvadersGame {
  constructor(canvas) {
    this.canvas = canvas;
    this.ctx = canvas.getContext('2d');
    canvas.width = CANVAS_W;
    canvas.height = CANVAS_H;
    this.input = { left: false, right: false, fire: false };
    this.reset();
  }

  reset() {
    this.score = 0;
    this.lives = 3;
    this.wave = 1;
    this.over = false;
    this.player = { x: CANVAS_W / 2 - PLAYER_W / 2, y: PLAYER_Y };
    this.bullets = [];
    this.enemyBullets = [];
    this.fireTimer = 0;
    this.hitFlash = 0;
    this.spawnWave();
  }

  spawnWave() {
    this.enemies = [];
    const totalWidth = ENEMY_COLS * (ENEMY_W + ENEMY_GAP_X) - ENEMY_GAP_X;
    const startX = (CANVAS_W - totalWidth) / 2;
    for (let row = 0; row < ENEMY_ROWS; row++) {
      for (let col = 0; col < ENEMY_COLS; col++) {
        this.enemies.push({
          x: startX + col * (ENEMY_W + ENEMY_GAP_X),
          y: ENEMY_TOP + row * (ENEMY_H + ENEMY_GAP_Y),
          w: ENEMY_W,
          h: ENEMY_H,
          alive: true,
          points: (ENEMY_ROWS - row) * 10,
        });
      }
    }
    this.enemyDir = 1;
    this.enemySpeed = 30 + (this.wave - 1) * 12;
    this.enemyShootTimer = 0;
  }

  aliveEnemies() {
    return this.enemies.filter((e) => e.alive);
  }

  tick(dtMs) {
    if (this.over) return;
    const dt = dtMs / 1000;

    if (this.input.left) this.player.x -= PLAYER_SPEED * dt;
    if (this.input.right) this.player.x += PLAYER_SPEED * dt;
    this.player.x = Math.max(0, Math.min(CANVAS_W - PLAYER_W, this.player.x));

    this.fireTimer -= dtMs;
    if (this.input.fire && this.fireTimer <= 0) {
      this.bullets.push({ x: this.player.x + PLAYER_W / 2 - 2, y: this.player.y, w: 4, h: 10 });
      this.fireTimer = FIRE_COOLDOWN_MS;
    }

    for (const b of this.bullets) b.y -= BULLET_SPEED * dt;
    this.bullets = this.bullets.filter((b) => b.y + b.h > 0);

    for (const b of this.enemyBullets) b.y += ENEMY_BULLET_SPEED * dt;
    this.enemyBullets = this.enemyBullets.filter((b) => b.y < CANVAS_H);

    const alive = this.aliveEnemies();
    if (alive.length === 0) {
      this.wave += 1;
      this.spawnWave();
      return;
    }

    let hitEdge = false;
    for (const e of alive) {
      e.x += this.enemyDir * this.enemySpeed * dt;
      if (e.x <= 0 || e.x + e.w >= CANVAS_W) hitEdge = true;
    }
    if (hitEdge) {
      this.enemyDir *= -1;
      for (const e of alive) {
        e.y += ENEMY_STEP_DOWN;
        if (e.y + e.h >= this.player.y) {
          this.over = true;
        }
      }
    }

    this.enemyShootTimer -= dtMs;
    if (this.enemyShootTimer <= 0 && alive.length > 0) {
      const shooter = alive[Math.floor(Math.random() * alive.length)];
      this.enemyBullets.push({ x: shooter.x + shooter.w / 2 - 2, y: shooter.y + shooter.h, w: 4, h: 10 });
      this.enemyShootTimer = Math.max(250, 900 - this.wave * 60);
    }

    // пуля игрока vs враги
    for (const bullet of this.bullets) {
      for (const e of alive) {
        if (!e.alive) continue;
        if (rectsOverlap(bullet, e)) {
          e.alive = false;
          bullet.hit = true;
          this.score += e.points;
        }
      }
    }
    this.bullets = this.bullets.filter((b) => !b.hit);

    // пуля врага vs игрок
    const playerRect = { x: this.player.x, y: this.player.y, w: PLAYER_W, h: PLAYER_H };
    for (const b of this.enemyBullets) {
      if (rectsOverlap(b, playerRect)) {
        b.hit = true;
        this.lives -= 1;
        this.hitFlash = 200;
        if (this.lives <= 0) this.over = true;
      }
    }
    this.enemyBullets = this.enemyBullets.filter((b) => !b.hit);

    if (this.hitFlash > 0) this.hitFlash -= dtMs;
  }

  draw() {
    const ctx = this.ctx;
    ctx.fillStyle = '#0a0e0c';
    ctx.fillRect(0, 0, CANVAS_W, CANVAS_H);

    for (const e of this.enemies) {
      if (!e.alive) continue;
      ctx.fillStyle = '#39e075';
      ctx.fillRect(e.x, e.y, e.w, e.h);
      ctx.fillStyle = '#0a0e0c';
      ctx.fillRect(e.x + 4, e.y + 4, 4, 4);
      ctx.fillRect(e.x + e.w - 8, e.y + 4, 4, 4);
    }

    ctx.fillStyle = this.hitFlash > 0 ? '#ffffff' : '#00ff41';
    ctx.fillRect(this.player.x, this.player.y, PLAYER_W, PLAYER_H);
    ctx.fillRect(this.player.x + PLAYER_W / 2 - 3, this.player.y - 6, 6, 6);

    ctx.fillStyle = '#c7c7c7';
    for (const b of this.bullets) ctx.fillRect(b.x, b.y, b.w, b.h);
    ctx.fillStyle = '#9fa3a0';
    for (const b of this.enemyBullets) ctx.fillRect(b.x, b.y, b.w, b.h);
  }
}

let game = null;
let rafId = null;

function updateStats() {
  document.getElementById('arcade-score').textContent = game.score;
  document.getElementById('arcade-lives').textContent = game.lives;
  document.getElementById('arcade-wave').textContent = game.wave;
}

function showGameOver() {
  const overlay = document.getElementById('arcade-result-overlay');
  overlay.innerHTML = `
    <div class="arcade-result">
      <h2 class="glitch" data-text="${t().gameOver}">${t().gameOver}</h2>
      <p>${t().finalScore(game.score)}</p>
      <div class="arcade-result__actions">
        <button data-action="again">${t().again}</button>
      </div>
    </div>`;
  overlay.style.display = 'flex';
}

function loop(time) {
  if (game.lastTime === undefined || game.lastTime === null) game.lastTime = time;
  const dt = time - game.lastTime;
  game.lastTime = time;
  const wasOver = game.over;
  game.tick(dt);
  game.draw();
  updateStats();
  if (game.over && !wasOver) showGameOver();
  rafId = requestAnimationFrame(loop);
}

function restart() {
  const overlay = document.getElementById('arcade-result-overlay');
  overlay.style.display = 'none';
  overlay.innerHTML = '';
  game.reset();
}

function bindKeyboard() {
  window.addEventListener('keydown', (e) => {
    if (!game) return;
    if (game.over) {
      if (e.code === 'Space' || e.code === 'Enter') restart();
      return;
    }
    if (e.code === 'ArrowLeft') { game.input.left = true; e.preventDefault(); }
    if (e.code === 'ArrowRight') { game.input.right = true; e.preventDefault(); }
    if (e.code === 'Space') { game.input.fire = true; e.preventDefault(); }
  });
  window.addEventListener('keyup', (e) => {
    if (!game) return;
    if (e.code === 'ArrowLeft') game.input.left = false;
    if (e.code === 'ArrowRight') game.input.right = false;
    if (e.code === 'Space') game.input.fire = false;
  });
}

function bindTouchControls(root) {
  const press = (key, value) => {
    if (game) game.input[key] = value;
  };
  root.querySelectorAll('[data-input]').forEach((btn) => {
    const key = btn.dataset.input;
    btn.addEventListener('mousedown', () => press(key, true));
    btn.addEventListener('mouseup', () => press(key, false));
    btn.addEventListener('mouseleave', () => press(key, false));
    btn.addEventListener('touchstart', (e) => { e.preventDefault(); press(key, true); });
    btn.addEventListener('touchend', (e) => { e.preventDefault(); press(key, false); });
  });
}

function renderShell(root) {
  root.innerHTML = `
    <p class="arcade-crosslinks"><span id="arcade-crosslinks-label">${t().crosslinks}</span> <a href="/game">./tanks</a> · <a href="/blocks">./blocks</a></p>
    <div class="arcade-layout">
      <div class="arcade-canvas-slot">
        <canvas id="arcade-canvas"></canvas>
        <div id="arcade-result-overlay" class="arcade-result-overlay"></div>
      </div>
      <div class="arcade-controls">
        <div class="arcade-stats">
          <div><span id="arcade-score-label">${t().score.toUpperCase()}</span> <b id="arcade-score">0</b></div>
          <div><span id="arcade-lives-label">${t().lives.toUpperCase()}</span> <b id="arcade-lives">3</b></div>
          <div><span id="arcade-wave-label">${t().wave.toUpperCase()}</span> <b id="arcade-wave">1</b></div>
        </div>
        <p class="arcade-controls__hint" id="arcade-hint">${t().hint}</p>
        <div class="arcade-lr">
          <button data-input="left">&larr;</button>
          <button data-input="right">&rarr;</button>
        </div>
        <button class="arcade-action-btn" data-input="fire" id="arcade-fire-btn">${t().fire}</button>
      </div>
    </div>`;
}

function updateStaticText() {
  const byId = (id) => document.getElementById(id);
  if (byId('arcade-crosslinks-label')) byId('arcade-crosslinks-label').textContent = t().crosslinks;
  if (byId('arcade-score-label')) byId('arcade-score-label').textContent = t().score.toUpperCase();
  if (byId('arcade-lives-label')) byId('arcade-lives-label').textContent = t().lives.toUpperCase();
  if (byId('arcade-wave-label')) byId('arcade-wave-label').textContent = t().wave.toUpperCase();
  if (byId('arcade-hint')) byId('arcade-hint').textContent = t().hint;
  if (byId('arcade-fire-btn')) byId('arcade-fire-btn').textContent = t().fire;
  if (game?.over) showGameOver();
}

function init() {
  const root = document.getElementById('arcade-root');
  renderShell(root);

  const canvas = document.getElementById('arcade-canvas');
  game = new InvadersGame(canvas);

  bindTouchControls(root.querySelector('.arcade-controls'));
  root.querySelector('#arcade-result-overlay').addEventListener('click', (e) => {
    if (e.target.closest('[data-action="again"]')) restart();
  });

  if (rafId) cancelAnimationFrame(rafId);
  rafId = requestAnimationFrame(loop);
}

bindKeyboard();
init();
initLangToggle(updateStaticText);