{% extends "base.html" %}
{% block title %}Duplicate Documents - DocuElevate{% endblock %}

{% block head_extra %}
<style>
  .dup-container { max-width: 1100px; margin: 0 auto; }
  .dup-group {
    background: white; border-radius: 0.5rem;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    margin-bottom: 1.5rem; overflow: hidden;
  }
  .dup-group-header {
    padding: 1rem 1.25rem;
    border-bottom: 1px solid #e5e7eb;
    display: flex; align-items: center; gap: 0.75rem;
    background: #f9fafb;
  }
  .dup-badge {
    display: inline-flex; align-items: center; gap: 0.3rem;
    font-size: 0.75rem; font-weight: 700; padding: 0.2rem 0.6rem;
    border-radius: 9999px;
  }
  .dup-badge-exact  { background: #fee2e2; color: #991b1b; }
  .dup-badge-near   { background: #fef3c7; color: #92400e; }
  .dup-file-row {
    display: flex; align-items: center; gap: 0.75rem;
    padding: 0.75rem 1.25rem; border-bottom: 1px solid #f3f4f6;
  }
  .dup-file-row:last-child { border-bottom: none; }
  .dup-file-row.original { background: #f0fdf4; }
  .dup-file-row.duplicate { background: #fff7ed; }
  .dup-file-row.near-dup  { background: #fffbeb; }
  .dup-role-tag {
    font-size: 0.7rem; font-weight: 700; padding: 0.15rem 0.5rem;
    border-radius: 9999px; white-space: nowrap;
  }
  .tag-original  { background: #d1fae5; color: #065f46; }
  .tag-duplicate { background: #fee2e2; color: #991b1b; }
  .tag-near      { background: #fef3c7; color: #92400e; }
  .dup-filename { font-weight: 600; color: #1f2937; word-break: break-all; }
  .dup-meta { font-size: 0.8rem; color: #6b7280; }
  .dup-score { font-size: 0.8rem; font-weight: 700; color: #d97706; }
  .dup-actions { margin-left: auto; display: flex; gap: 0.5rem; flex-shrink: 0; }

  /* near-dup search UI */
  .near-dup-search {
    background: white; border-radius: 0.5rem;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    padding: 1.25rem; margin-bottom: 2rem;
  }
  .near-dup-search h3 { font-size: 1rem; font-weight: 700; margin-bottom: 0.75rem; }
  .nd-form { display: flex; gap: 0.5rem; flex-wrap: wrap; align-items: flex-end; }
  .nd-form label { font-size: 0.8rem; font-weight: 600; color: #374151; }
  .nd-form input, .nd-form select {
    padding: 0.4rem 0.6rem; border: 1px solid #d1d5db;
    border-radius: 0.375rem; font-size: 0.85rem;
  }
  .nd-form input[type=number] { width: 90px; }
  .nd-results { margin-top: 1rem; }

  .empty-state {
    text-align: center; padding: 3rem; color: #6b7280;
  }
  .empty-state i { font-size: 3rem; margin-bottom: 0.75rem; display: block; }
  .tabs { display: flex; gap: 0; border-bottom: 2px solid #e5e7eb; margin-bottom: 1.5rem; }
  .tab-btn {
    padding: 0.6rem 1.25rem; font-weight: 600; font-size: 0.9rem;
    cursor: pointer; border: none; background: none;
    border-bottom: 3px solid transparent; margin-bottom: -2px;
    color: #6b7280; transition: color .15s;
  }
  .tab-btn.active { color: #2563eb; border-bottom-color: #2563eb; }
  .tab-panel { display: none; }
  .tab-panel.active { display: block; }

  /* pagination */
  .pagination { display: flex; gap: 0.5rem; justify-content: center; margin-top: 1.5rem; }
  .page-btn {
    padding: 0.4rem 0.75rem; border: 1px solid #d1d5db;
    border-radius: 0.375rem; font-size: 0.85rem; cursor: pointer;
    background: white; color: #374151;
  }
  .page-btn:hover:not(:disabled) { background: #f3f4f6; }
  .page-btn:disabled { opacity: 0.4; cursor: default; }
  .page-btn.current { background: #2563eb; color: white; border-color: #2563eb; }
</style>
{% endblock %}

{% block content %}
<main id="main-content" class="dup-container px-4 py-8">
  <h1 class="text-2xl font-bold mb-2">Duplicate Documents</h1>
  <p class="text-gray-500 mb-6 text-sm">
    Documents with identical content (same SHA-256 hash) are shown as
    <span class="dup-badge dup-badge-exact">exact duplicates</span>.
    Use the <strong>Near-Duplicate Finder</strong> tab to detect documents with the
    same scanned content but different hashes — for example, a document scanned
    twice.
  </p>

  <!-- Tabs -->
  <div class="tabs" role="tablist" aria-label="Duplicate detection tabs">
    <button class="tab-btn active" role="tab" aria-selected="true"
            aria-controls="tab-exact" id="btn-exact"
            onclick="switchTab('exact')">
      <i class="fas fa-clone mr-1" aria-hidden="true"></i>
      Exact Duplicates
      {% if total_groups is defined %}
        <span class="ml-1 text-xs bg-red-100 text-red-700 font-bold px-1.5 rounded-full">
          {{ total_groups }}
        </span>
      {% endif %}
    </button>
    <button class="tab-btn" role="tab" aria-selected="false"
            aria-controls="tab-near" id="btn-near"
            onclick="switchTab('near')">
      <i class="fas fa-layer-group mr-1" aria-hidden="true"></i>
      Near-Duplicate Finder
    </button>
  </div>

  <!-- ── Tab: Exact Duplicates ── -->
  <div id="tab-exact" class="tab-panel active" role="tabpanel" aria-labelledby="btn-exact">

    {% if groups %}
      <p class="text-sm text-gray-500 mb-4">
        Found <strong>{{ total_groups }}</strong> duplicate group(s) with
        <strong>{{ total_duplicate_files }}</strong> duplicate file(s) total.
      </p>

      {% for group in groups %}
      <section class="dup-group" aria-label="Duplicate group {{ loop.index }}">
        <div class="dup-group-header">
          <i class="fas fa-fingerprint text-gray-400" aria-hidden="true"></i>
          <span class="text-xs font-mono text-gray-500" title="SHA-256 hash">
            {{ group.filehash[:16] }}…
          </span>
          <span class="dup-badge dup-badge-exact">
            <i class="fas fa-copy" aria-hidden="true"></i>
            {{ group.duplicate_count }} duplicate{{ 's' if group.duplicate_count != 1 else '' }}
          </span>
        </div>

        <!-- Original file -->
        {% if group.original %}
        <div class="dup-file-row original">
          <span class="dup-role-tag tag-original">Original</span>
          <div class="flex-1 min-w-0">
            <div class="dup-filename">
              <a href="/files/{{ group.original.id }}"
                 class="hover:text-blue-600">
                {{ group.original.original_filename or '(unnamed)' }}
              </a>
            </div>
            <div class="dup-meta">
              ID: {{ group.original.id }}
              {% if group.original.file_size %}
                · {{ (group.original.file_size / 1024)|round(1) }} KB
              {% endif %}
              {% if group.original.created_at %}
                · {{ group.original.created_at[:19].replace('T',' ') }}
              {% endif %}
            </div>
          </div>
          <div class="dup-actions">
            <a href="/files/{{ group.original.id }}"
               class="text-sm text-blue-600 hover:underline"
               aria-label="View original file {{ group.original.original_filename }}">
              <i class="fas fa-external-link-alt" aria-hidden="true"></i> View
            </a>
          </div>
        </div>
        {% endif %}

        <!-- Duplicate files -->
        {% for dup in group.duplicates %}
        <div class="dup-file-row duplicate">
          <span class="dup-role-tag tag-duplicate">Duplicate</span>
          <div class="flex-1 min-w-0">
            <div class="dup-filename">
              <a href="/files/{{ dup.id }}" class="hover:text-blue-600">
                {{ dup.original_filename or '(unnamed)' }}
              </a>
            </div>
            <div class="dup-meta">
              ID: {{ dup.id }}
              {% if dup.file_size %}
                · {{ (dup.file_size / 1024)|round(1) }} KB
              {% endif %}
              {% if dup.created_at %}
                · {{ dup.created_at[:19].replace('T',' ') }}
              {% endif %}
            </div>
          </div>
          <div class="dup-actions">
            <a href="/files/{{ dup.id }}"
               class="text-sm text-blue-600 hover:underline"
               aria-label="View duplicate file {{ dup.original_filename }}">
              <i class="fas fa-external-link-alt" aria-hidden="true"></i> View
            </a>
          </div>
        </div>
        {% endfor %}
      </section>
      {% endfor %}

      <!-- Pagination -->
      {% if pagination.pages > 1 %}
      <nav class="pagination" aria-label="Pagination">
        <button class="page-btn" onclick="changePage({{ pagination.page - 1 }})"
                {% if pagination.page <= 1 %}disabled{% endif %}
                aria-label="Previous page">
          <i class="fas fa-chevron-left" aria-hidden="true"></i>
        </button>
        {% for p in range(1, pagination.pages + 1) %}
          <button class="page-btn {% if p == pagination.page %}current{% endif %}"
                  onclick="changePage({{ p }})"
                  aria-label="Page {{ p }}"
                  {% if p == pagination.page %}aria-current="page"{% endif %}>
            {{ p }}
          </button>
        {% endfor %}
        <button class="page-btn" onclick="changePage({{ pagination.page + 1 }})"
                {% if pagination.page >= pagination.pages %}disabled{% endif %}
                aria-label="Next page">
          <i class="fas fa-chevron-right" aria-hidden="true"></i>
        </button>
      </nav>
      {% endif %}

    {% else %}
      <div class="empty-state">
        <i class="fas fa-check-circle text-green-400" aria-hidden="true"></i>
        <p class="font-semibold text-lg text-gray-700">No exact duplicates found</p>
        <p class="text-sm mt-1">
          Every file in the system has a unique SHA-256 hash.
          Use the <strong>Near-Duplicate Finder</strong> tab to check for
          re-scanned documents.
        </p>
      </div>
    {% endif %}
  </div><!-- /tab-exact -->

  <!-- ── Tab: Near-Duplicate Finder ── -->
  <div id="tab-near" class="tab-panel" role="tabpanel" aria-labelledby="btn-near">

    <div class="near-dup-search">
      <h3>
        <i class="fas fa-search mr-1 text-yellow-500" aria-hidden="true"></i>
        Find Near-Duplicates for a Document
      </h3>
      <p class="text-sm text-gray-500 mb-4">
        Select a document to check whether any other files contain the same (or very
        similar) content — even if they were scanned at different times and have
        different SHA-256 hashes.  Similarity is computed from OCR text embeddings;
        documents without extracted text cannot be compared.
      </p>

      <form id="nearDupForm" onsubmit="findNearDups(event)">
        <div class="nd-form">
          <div class="flex flex-col gap-1">
            <label for="ndFileId">File ID</label>
            <input type="number" id="ndFileId" name="file_id" min="1"
                   placeholder="e.g. 42" required
                   style="min-height:44px;">
          </div>
          <div class="flex flex-col gap-1">
            <label for="ndThreshold">Similarity threshold</label>
            <input type="number" id="ndThreshold" name="threshold"
                   min="0" max="1" step="0.05"
                   value="{{ near_duplicate_threshold }}"
                   style="min-height:44px;">
          </div>
          <div class="flex flex-col gap-1">
            <label for="ndLimit">Max results</label>
            <select id="ndLimit" name="limit" style="min-height:44px;">
              <option value="5" selected>5</option>
              <option value="10">10</option>
              <option value="20">20</option>
            </select>
          </div>
          <button type="submit"
                  class="bg-yellow-500 hover:bg-yellow-600 text-white font-bold
                         px-5 rounded-lg transition-colors"
                  style="min-height:44px;">
            <i class="fas fa-search mr-1" aria-hidden="true"></i> Find
          </button>
        </div>
      </form>

      <div id="ndStatus" class="mt-3 text-sm text-gray-500" aria-live="polite"></div>

      <div id="ndResults" class="nd-results" aria-live="polite"></div>
    </div>

    <!-- How it works explanation -->
    <div class="bg-blue-50 border border-blue-200 rounded-lg p-4 text-sm text-blue-800">
      <p class="font-semibold mb-1">
        <i class="fas fa-info-circle mr-1" aria-hidden="true"></i>
        How near-duplicate detection works
      </p>
      <ul class="list-disc ml-5 space-y-1">
        <li>After OCR processes a document, its text is converted to a numeric
            <em>embedding vector</em> using an AI language model.</li>
        <li>Near-duplicate detection compares these vectors using <em>cosine
            similarity</em>: a score of 1.0 means identical content, 0.0 means
            completely different.</li>
        <li>A threshold of <strong>{{ near_duplicate_threshold }}</strong> means
            documents must share at least
            {{ (near_duplicate_threshold * 100)|round|int }}% semantic similarity
            to be flagged.</li>
        <li>Documents scanned twice (even with slight differences) will typically
            score <strong>&gt; 0.90</strong>.</li>
      </ul>
    </div>
  </div><!-- /tab-near -->

</main>
{% endblock %}

{% block scripts %}
<script>
  // ── Tab switching ──────────────────────────────────────────────────────────
  function switchTab(name) {
    document.querySelectorAll('.tab-btn').forEach(btn => {
      const active = btn.id === 'btn-' + name;
      btn.classList.toggle('active', active);
      btn.setAttribute('aria-selected', active ? 'true' : 'false');
    });
    document.querySelectorAll('.tab-panel').forEach(panel => {
      panel.classList.toggle('active', panel.id === 'tab-' + name);
    });
  }

  // ── Pagination ─────────────────────────────────────────────────────────────
  function changePage(p) {
    const url = new URL(window.location.href);
    url.searchParams.set('page', p);
    window.location.href = url.toString();
  }

  // ── Near-duplicate API call ───────────────────────────────────────────────
  async function findNearDups(e) {
    e.preventDefault();
    const fileId   = document.getElementById('ndFileId').value.trim();
    const threshold = parseFloat(document.getElementById('ndThreshold').value) || 0.85;
    const limit    = parseInt(document.getElementById('ndLimit').value) || 5;
    const status   = document.getElementById('ndStatus');
    const results  = document.getElementById('ndResults');

    if (!fileId) {
      status.textContent = 'Please enter a File ID.';
      return;
    }

    status.textContent = 'Searching…';
    results.innerHTML  = '';

    try {
      const url = `/api/files/${encodeURIComponent(fileId)}/duplicates`
        + `?near_duplicate_threshold=${threshold}&near_duplicate_limit=${limit}`;
      const csrfToken = document.querySelector('meta[name="csrf-token"]')?.content;
      if (!csrfToken) {
        status.textContent = 'Security token not found. Please reload the page.';
        return;
      }
      const resp = await fetch(url, {
        headers: { 'X-CSRF-Token': csrfToken }
      });

      if (!resp.ok) {
        const err = await resp.json().catch(() => ({}));
        status.textContent = `Error ${resp.status}: ${err.detail || resp.statusText}`;
        return;
      }

      const data = await resp.json();
      renderNearDupResults(data, threshold);
      status.textContent = '';
    } catch (err) {
      status.textContent = `Network error: ${err.message}`;
    }
  }

  function renderNearDupResults(data, threshold) {
    const container = document.getElementById('ndResults');

    if (!data.near_duplicates || data.near_duplicates.length === 0) {
      container.innerHTML = `
        <div class="empty-state py-6">
          <i class="fas fa-check-circle text-green-400 text-3xl mb-2" aria-hidden="true"></i>
          <p class="font-semibold text-gray-700">No near-duplicates found</p>
          <p class="text-sm text-gray-500 mt-1">
            No other document exceeded the ${(threshold * 100).toFixed(0)}% similarity threshold.
            ${!data.near_duplicates ? 'This file may not have OCR text yet.' : ''}
          </p>
        </div>`;
      return;
    }

    let html = `<h4 class="font-semibold text-gray-700 mb-2 mt-2">
      Found <strong>${data.near_duplicate_count}</strong> near-duplicate(s) for file #${data.file_id}
    </h4>
    <div class="dup-group">`;

    // Show target file header
    html += `
      <div class="dup-group-header">
        <i class="fas fa-file-alt text-gray-400" aria-hidden="true"></i>
        <span class="text-sm font-semibold">Reference file: ID ${data.file_id}</span>
        <span class="dup-badge dup-badge-near ml-auto">
          Threshold ≥ ${(data.near_duplicate_threshold * 100).toFixed(0)}%
        </span>
      </div>`;

    data.near_duplicates.forEach(nd => {
      const scorePercent = (nd.similarity_score * 100).toFixed(1);
      const scoreColor   = nd.similarity_score >= 0.95
        ? 'text-red-600' : nd.similarity_score >= 0.85
        ? 'text-yellow-600' : 'text-orange-500';
      const createdAt = nd.created_at ? nd.created_at.substring(0, 19).replace('T', ' ') : '';

      html += `
        <div class="dup-file-row near-dup">
          <span class="dup-role-tag tag-near">Near-Dup</span>
          <div class="flex-1 min-w-0">
            <div class="dup-filename">
              <a href="/files/${nd.file_id}" class="hover:text-blue-600">
                ${escapeHtml(nd.original_filename || '(unnamed)')}
              </a>
            </div>
            <div class="dup-meta">
              ID: ${nd.file_id}
              ${nd.document_title ? ' · ' + escapeHtml(nd.document_title) : ''}
              ${createdAt ? ' · ' + createdAt : ''}
            </div>
          </div>
          <div class="dup-actions items-center">
            <span class="dup-score ${scoreColor}" title="Cosine similarity score">
              ${scorePercent}% match
            </span>
            <a href="/files/${nd.file_id}"
               class="text-sm text-blue-600 hover:underline ml-2"
               aria-label="View file ${escapeHtml(nd.original_filename || '')}">
              <i class="fas fa-external-link-alt" aria-hidden="true"></i>
            </a>
          </div>
        </div>`;
    });

    html += '</div>';
    container.innerHTML = html;
  }

  function escapeHtml(str) {
    return String(str)
      .replace(/&/g, '&amp;')
      .replace(/</g, '&lt;')
      .replace(/>/g, '&gt;')
      .replace(/"/g, '&quot;');
  }

  // Pre-fill file ID from query string (e.g. /duplicates?file_id=42&tab=near)
  (function () {
    const params = new URLSearchParams(window.location.search);
    const fid = params.get('file_id');
    if (fid) document.getElementById('ndFileId').value = fid;
    const tab = params.get('tab');
    if (tab === 'near') switchTab('near');
  })();
</script>
{% endblock %}