(() => {
  'use strict';

  let overlay = null;
  let lastScore = 0;
  let lastNewBest = false;

  async function getBest(label) {
    const key = 'best-score:' + label;
    const legacyHighScore = Number(localStorage.getItem('highScore')) || 0;
    const stored = Number(await window.ParleySave?.load?.(key)) || Number(localStorage.getItem(key)) || legacyHighScore || 0;
    return { key, best: stored };
  }

  async function show({ score = 0, wave = 1, label = 'nova-tap' } = {}) {
    if (!overlay) return;
    lastScore = score;
    const { key, best: previousBest } = await getBest(label);
    const best = Math.max(previousBest, score);
    lastNewBest = best > previousBest;
    if (lastNewBest) {
      await window.ParleySave?.save?.(key, best);
      try {
        localStorage.setItem(key, String(best));
        localStorage.setItem('highScore', String(best));
      } catch (_) {}
    } else {
      try {
        const legacyHighScore = Number(localStorage.getItem('highScore')) || 0;
        if (best > legacyHighScore) localStorage.setItem('highScore', String(best));
      } catch (_) {}
    }
    overlay.querySelector('[data-slot="score"]').textContent = Math.floor(score).toLocaleString();
    overlay.querySelector('[data-slot="best"]').textContent = Math.floor(best).toLocaleString();
    overlay.querySelector('[data-slot="wave"]').textContent = String(wave);
    overlay.querySelector('[data-slot="newbest"]').textContent = lastNewBest ? 'NEW HIGH SCORE!' : 'Chase your best run.';
    overlay.classList.add('visible');
  }

  function hide() { overlay?.classList.remove('visible'); }

  function mount() {
    overlay = document.createElement('div');
    overlay.id = 'parley-gameover-overlay';
    overlay.innerHTML = `
      <div class="parley-panel">
        <h2 class="parley-panel-title">Run Over</h2>
        <p class="parley-panel-subtitle" data-slot="newbest">Chase your best run.</p>
        <div class="parley-score-row"><span>Final score</span><strong data-slot="score">0</strong></div>
        <div class="parley-score-row"><span>Best score</span><strong data-slot="best">0</strong></div>
        <div class="parley-score-row"><span>Reached wave</span><strong data-slot="wave">1</strong></div>
        <button class="parley-btn" data-action="restart">Restart</button>
        <button class="parley-btn parley-btn-ghost" data-action="share">Share Score</button>
      </div>
    `;
    document.body.appendChild(overlay);
    overlay.addEventListener('click', async (event) => {
      const action = event.target.closest('[data-action]')?.dataset.action;
      if (action === 'restart') {
        hide();
        window.dispatchEvent(new CustomEvent('parley:restart'));
      }
      if (action === 'share') {
        const text = `I scored ${Math.floor(lastScore).toLocaleString()} in Nova Tap!`;
        const url = `https://twitter.com/intent/tweet?text=${encodeURIComponent(text + ' ' + location.href)}`;
        window.open(url, '_blank', 'noopener,noreferrer');
      }
    });
  }

  window.addEventListener('DOMContentLoaded', mount);
  window.ParleyGameOver = { show, hide, get lastNewBest() { return lastNewBest; } };
})();