{% extends "base.html" %}
{% block banner_subtitle %}Compare Decks{% endblock %}
{% block content %}
<h2>Compare Decks</h2>
<p class="muted">Pick two finished decks to compare. You can get here from Finished Decks or deck view pages.</p>

<form method="get" action="/decks/compare" class="panel" style="display:flex; gap:.5rem; align-items:center; flex-wrap:wrap;">
  <label>Deck A
    <select name="A" required>
      <option value="">Choose…</option>
      {% for opt in options %}
        <option value="{{ opt.name }}" data-mtime="{{ opt.mtime }}" {% if A == opt.name %}selected{% endif %}>{{ opt.label }}</option>
      {% endfor %}
    </select>
  </label>
  <label>Deck B
    <select name="B" required>
      <option value="">Choose…</option>
      {% for opt in options %}
        <option value="{{ opt.name }}" data-mtime="{{ opt.mtime }}" {% if B == opt.name %}selected{% endif %}>{{ opt.label }}</option>
      {% endfor %}
    </select>
  </label>
  <button type="submit">Compare</button>
  <button type="button" id="cmp-swap" class="btn" title="Swap A and B" style="margin-left:.25rem;">Swap A/B</button>
  <button type="button" id="cmp-latest" class="btn" title="Pick the latest two decks">Latest two</button>
</form>

{% if diffs %}
  <div class="panel" style="margin-top:.75rem;">
    <div style="display:flex; gap:1rem; flex-wrap:wrap; align-items:center;">
      <div>
        <strong>A:</strong> {{ metaA.display or metaA.filename }}
        {% if metaA.commander %}<span class="muted">({{ metaA.commander }})</span>{% endif %}
        {% if metaA.tags %}<div class="muted">{{ metaA.tags }}</div>{% endif %}
      </div>
      <div>
        <strong>B:</strong> {{ metaB.display or metaB.filename }}
        {% if metaB.commander %}<span class="muted">({{ metaB.commander }})</span>{% endif %}
        {% if metaB.tags %}<div class="muted">{{ metaB.tags }}</div>{% endif %}
      </div>
  <div style="margin-left:auto; display:flex; gap:.5rem; align-items:center;">
    <button type="button" id="cmp-copy" class="btn" title="Copy a plain-text summary of the diffs">Copy summary</button>
    <button type="button" id="cmp-download" class="btn" title="Download a plain-text summary of the diffs">Download .txt</button>
  </div>
    </div>
  </div>

  <div class="panel" style="margin-top:.5rem; display:flex; gap:1rem; align-items:center; flex-wrap:wrap;">
    <div class="muted">Totals:
      <strong id="totA">{{ (diffs.onlyA|length) if diffs.onlyA else 0 }}</strong> only-in-A,
      <strong id="totB">{{ (diffs.onlyB|length) if diffs.onlyB else 0 }}</strong> only-in-B,
      <strong id="totC">{{ (diffs.changed|length) if diffs.changed else 0 }}</strong> changed
    </div>
    <label class="muted" style="margin-left:auto; display:flex; align-items:center; gap:.35rem;">
  <input type="checkbox" id="cmp-changed-only" /> Changed only
    </label>
  </div>

  <div class="only-panels" style="display:grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-top:.75rem;">
    <div class="panel onlyA">
      <h3 style="margin-top:0;">Only in A</h3>
      {% if diffs.onlyA and diffs.onlyA|length %}
        <ul>
          {% for n in diffs.onlyA %}<li>{{ n }}</li>{% endfor %}
        </ul>
      {% else %}
        <div class="muted">None</div>
      {% endif %}
    </div>
    <div class="panel onlyB">
      <h3 style="margin-top:0;">Only in B</h3>
      {% if diffs.onlyB and diffs.onlyB|length %}
        <ul>
          {% for n in diffs.onlyB %}<li>{{ n }}</li>{% endfor %}
        </ul>
      {% else %}
        <div class="muted">None</div>
      {% endif %}
    </div>
  </div>

  <div class="panel" style="margin-top:1rem;">
    <h3 style="margin-top:0;">Changed counts</h3>
    {% if diffs.changed and diffs.changed|length %}
      <ul class="changed-list">
        {% for n, a, b in diffs.changed %}
          {% set delta = b - a %}
          {% if delta > 0 %}
            <li class="chg inc" title="Increased in B">▲ {{ n }}: A={{ a }}, B={{ b }} (+{{ delta }})</li>
          {% elif delta < 0 %}
            <li class="chg dec" title="Decreased in B">▼ {{ n }}: A={{ a }}, B={{ b }} ({{ delta }})</li>
          {% else %}
            <li class="chg">{{ n }}: A={{ a }}, B={{ b }}</li>
          {% endif %}
        {% endfor %}
      </ul>
    {% else %}
      <div class="muted">None</div>
    {% endif %}
  </div>
  <script id="cmp-data" type="application/json">{{ {
      'aLabel': (metaA.display or metaA.filename),
      'bLabel': (metaB.display or metaB.filename),
      'onlyA': diffs.onlyA or [],
      'onlyB': diffs.onlyB or [],
      'changed': diffs.changed or []
    } | tojson }}</script>
  <script>
  (function(){
    var copyBtn = document.getElementById('cmp-copy');
    var dlBtn = document.getElementById('cmp-download');
    var changedOnly = document.getElementById('cmp-changed-only');
    var dataEl = document.getElementById('cmp-data');
    var data = null;
    try { data = JSON.parse((dataEl && dataEl.textContent) ? dataEl.textContent : 'null'); } catch(e) { data = null; }
    function buildLines(){
      var lines = [];
      lines.push('Compare:');
      lines.push('A: ' + data.aLabel);
      lines.push('B: ' + data.bLabel);
      lines.push('');
      if (!changedOnly || !changedOnly.checked) {
        lines.push('Only in A:');
        if (data.onlyA && data.onlyA.length) { data.onlyA.forEach(function(n){ lines.push('- ' + n); }); }
        else { lines.push('(none)'); }
        lines.push('');
        lines.push('Only in B:');
        if (data.onlyB && data.onlyB.length) { data.onlyB.forEach(function(n){ lines.push('- ' + n); }); }
        else { lines.push('(none)'); }
        lines.push('');
      }
      lines.push('Changed counts:');
      if (data.changed && data.changed.length) {
        data.changed.forEach(function(row){ lines.push('- ' + row[0] + ': A=' + row[1] + ', B=' + row[2]); });
      } else { lines.push('(none)'); }
      return lines;
    }
    if (copyBtn) copyBtn.addEventListener('click', function(){
      try{
        var txt = buildLines().join('\n');
        if (navigator.clipboard && navigator.clipboard.writeText){ navigator.clipboard.writeText(txt); }
        else {
          var ta = document.createElement('textarea'); ta.value = txt; document.body.appendChild(ta); ta.select(); try{ document.execCommand('copy'); }catch(_){} document.body.removeChild(ta);
        }
        if (window.toast) window.toast('Copied comparison');
      }catch(_){ }
    });
    if (dlBtn) dlBtn.addEventListener('click', function(){
      try{
        var txt = buildLines().join('\n');
        var blob = new Blob([txt], {type:'text/plain'});
        var url = URL.createObjectURL(blob);
        var a = document.createElement('a');
        a.href = url;
        a.download = 'compare.txt';
        document.body.appendChild(a);
        a.click();
        setTimeout(function(){ try{ URL.revokeObjectURL(url); document.body.removeChild(a); }catch(_){ } }, 0);
      }catch(_){ }
    });
    function applyChangedOnlyFlag(){
      try{
        var wrap = document.querySelector('.only-panels');
        if (!wrap || !changedOnly) return;
        wrap.style.display = changedOnly.checked ? 'none' : 'grid';
      }catch(_){ }
    }
    if (changedOnly) {
      try {
        var saved = localStorage.getItem('compare:changedOnly');
        if (saved === '1') { changedOnly.checked = true; }
      } catch(_){ }
      applyChangedOnlyFlag();
      changedOnly.addEventListener('change', function(){
        try { localStorage.setItem('compare:changedOnly', this.checked ? '1' : '0'); } catch(_){ }
        applyChangedOnlyFlag();
      });
    }
    // Swap A/B
    var swapBtn = document.getElementById('cmp-swap');
    if (swapBtn) swapBtn.addEventListener('click', function(){
      try{
        var f = this.closest('form'); if(!f) return;
        var a = f.querySelector('select[name="A"]');
        var b = f.querySelector('select[name="B"]');
        if(!a || !b) return;
        var aVal = a.value, bVal = b.value;
        a.value = bVal; b.value = aVal;
        f.requestSubmit();
      }catch(_){ }
    });
    // Pick latest two by mtime from options metadata
    var latestBtn = document.getElementById('cmp-latest');
    if (latestBtn) latestBtn.addEventListener('click', function(){
      try{
        var f = this.closest('form'); if(!f) return;
        var a = f.querySelector('select[name="A"]');
        var b = f.querySelector('select[name="B"]');
        if(!a || !b) return;
        var opts = Array.from(a.querySelectorAll('option[value]')).filter(function(o){ return o.value; });
        opts.sort(function(x,y){
          var mx = parseInt(x.getAttribute('data-mtime') || '0', 10);
          var my = parseInt(y.getAttribute('data-mtime') || '0', 10);
          return (my - mx);
        });
        if (opts.length >= 2){
          var first = opts[0].value;
          var second = opts[1].value;
          a.value = first; b.value = second;
          f.requestSubmit();
        }
      }catch(_){ }
    });
  })();
  </script>
<style>
  .changed-list { list-style: none; padding-left: 0; }
  .changed-list .chg { padding: 2px 0; }
  .changed-list .chg.inc { color: #10b981; }
  .changed-list .chg.dec { color: #ef4444; }
  .only-panels .onlyA h3 { color: #60a5fa; }
  .only-panels .onlyB h3 { color: #f59e0b; }
</style>
{% endif %}
{% endblock %}