const form = document.querySelector('#analysis-form');
const button = document.querySelector('#analyze-button');
const errorBox = document.querySelector('#error-message');
const results = document.querySelector('#dashboard');
const infoButtons = document.querySelectorAll('.info-button');
const drillTriggers = document.querySelectorAll('[data-detail]');
const drilldownTitle = document.querySelector('#drilldown-title');
const drilldownCount = document.querySelector('#drilldown-count');
const drilldownSummary = document.querySelector('#drilldown-summary');
const drilldownList = document.querySelector('#drilldown-list');
let latestAnalysis = null;

function expandHome(path) {
  return path.trim();
}

function escapeHtml(value) {
  return String(value ?? '').replace(/[&<>"']/g, (character) => ({
    '&': '&amp;',
    '<': '&lt;',
    '>': '&gt;',
    '"': '&quot;',
    "'": '&#039;',
  }[character]));
}

function detailLines(item) {
  if (item.files) {
    return item.files.map((file) => `<li>${escapeHtml(file)}</li>`).join('');
  }
  const lines = [];
  if (item.artist || item.title) lines.push(`${item.artist || 'Unknown artist'} — ${item.title || item.filename}`);
  if (item.crate) lines.push(`Crate: ${item.crate}`);
  if (item.saved_path) lines.push(`Saved path: ${item.saved_path}`);
  if (item.candidate) lines.push(`Candidate: ${item.candidate}`);
  if (item.path) lines.push(`File: ${item.path}`);
  if (item.target) lines.push(`Target: ${item.target}`);
  if (item.score || item.reason) lines.push(`${item.score || 'Match'} · ${item.reason || 'Candidate found'}`);
  if (item.repeated_filename) lines.push('Same filename appears more than once in Serato’s missing list.');
  return lines.map((line) => `<li>${escapeHtml(line)}</li>`).join('');
}

function renderDetail(key) {
  const detail = latestAnalysis?.details?.[key];
  if (!detail) return;

  drillTriggers.forEach((trigger) => {
    trigger.classList.toggle('selected', trigger.dataset.detail === key);
  });
  drilldownTitle.textContent = detail.title;
  drilldownCount.textContent = `${detail.total ?? 0} found`;
  drilldownSummary.textContent = detail.summary;

  if (!detail.items?.length) {
    drilldownList.innerHTML = '<div class="empty-detail">Nothing to review here. Tiny victory parade, very tasteful.</div>';
    return;
  }

  drilldownList.innerHTML = detail.items.map((item) => `
    <article class="detail-item">
      <strong>${escapeHtml(item.filename || item.path || 'Untitled item')}</strong>
      <ul>${detailLines(item)}</ul>
    </article>
  `).join('');
}

function render(data) {
  latestAnalysis = data;
  document.querySelectorAll('[data-field]').forEach((element) => {
    const value = data[element.dataset.field];
    element.textContent = value ?? '—';
  });
  const score = data.score;
  document.querySelector('#health-score').textContent = score == null ? '—' : `${score}%`;
  document.querySelector('#score-ring').style.setProperty('--score', score ?? 0);
  document.querySelector('#health-message').textContent = score == null
    ? 'Not enough data yet'
    : score >= 95 ? 'Looking excellent' : score >= 80 ? 'A few things need attention' : 'Review recommended';
  document.querySelector('#score-basis').textContent = data.score_basis;
  document.querySelector('#analysis-time').textContent = `Completed ${new Date().toLocaleTimeString([], {hour: '2-digit', minute: '2-digit'})}`;
  renderDetail(data.database_missing_paths > 0 ? 'database_missing_tracks' : 'old_crate_references');
  results.hidden = false;
  results.scrollIntoView({behavior: 'smooth', block: 'start'});
}

function closeInfoButtons(except = null) {
  infoButtons.forEach((infoButton) => {
    if (infoButton !== except) {
      infoButton.classList.remove('open');
      infoButton.setAttribute('aria-expanded', 'false');
    }
  });
}

infoButtons.forEach((infoButton) => {
  infoButton.addEventListener('click', (event) => {
    event.stopPropagation();
    const willOpen = !infoButton.classList.contains('open');
    closeInfoButtons(infoButton);
    infoButton.classList.toggle('open', willOpen);
    infoButton.setAttribute('aria-expanded', String(willOpen));
  });
});

drillTriggers.forEach((trigger) => {
  trigger.addEventListener('click', () => renderDetail(trigger.dataset.detail));
  trigger.addEventListener('keydown', (event) => {
    if (event.key === 'Enter' || event.key === ' ') {
      event.preventDefault();
      renderDetail(trigger.dataset.detail);
    }
  });
});

document.addEventListener('click', () => closeInfoButtons());
document.addEventListener('keydown', (event) => {
  if (event.key === 'Escape') closeInfoButtons();
});

form.addEventListener('submit', async (event) => {
  event.preventDefault();
  errorBox.hidden = true;
  button.disabled = true;
  button.querySelector('span').textContent = 'Analyzing safely…';
  const roots = document.querySelector('#reference-roots').value
    .split('\n').map((value) => value.trim()).filter(Boolean);
  try {
    const response = await fetch('/api/analyze', {
      method: 'POST',
      headers: {'Content-Type': 'application/json'},
      body: JSON.stringify({
        serato: expandHome(document.querySelector('#serato-path').value),
        music: expandHome(document.querySelector('#music-path').value),
        reference_roots: roots,
      }),
    });
    const data = await response.json();
    if (!response.ok) throw new Error(data.error || 'Analysis failed');
    render(data);
  } catch (error) {
    errorBox.textContent = error.message;
    errorBox.hidden = false;
  } finally {
    button.disabled = false;
    button.querySelector('span').textContent = 'Analyze library';
  }
});