From 25c51330868f3a71bc03b2ca8236aa3dedcd0780 Mon Sep 17 00:00:00 2001
From: Pontoporeia <pontoporeia@happyngreen.fr>
Date: Thu, 10 Sep 2026 14:49:57 +0200
Subject: [PATCH] =?UTF-8?q?perf(admin):=20infinite-scroll=20the=20contenus?=
 =?UTF-8?q?=20langues/mots-cl=C3=A9s=20tables?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The contenus page loaded both lookup tables in full via HTMX on page load:
760 tag rows + 216 language rows, ~2.4MB of HTML including ~1960 inline
SVG icons and per-row CSRF forms. The DB queries were already fast (~6ms);
the cost was pure client-side payload and DOM.

- Add paged lookups: getTagsPage/getLanguagesPage + countTagsWithCount/
  countLanguagesWithCount, and optional limit/offset on the existing
  unpaged variants (backward compatible).
- Fragments serve 25 rows per request. A sentinel <tr> with
  hx-trigger="intersect once root:#<wrap>" appends the next page when it
  scrolls into the table's own scroll container (htmx 'revealed' only
  checks the window viewport, not nested scrollers).
- Search forms still swap the whole wrapper and reset to offset 0.
- Style the load-more row; add PagedLanguagesTagsTest coverage.

Initial DOM for the page drops from ~2.4MB to ~160KB; scrolling reaches the
full totals (736 tags, 216 languages) and stops cleanly.
---
 TODO.md                                       |   3 +
 .../admin/contenus-langues-fragment.php       | 109 ++++++++---
 .../admin/contenus-motscles-fragment.php      | 109 ++++++++---
 app/public/assets/css/admin.css               |  16 ++
 app/src/Database.php                          | 126 ++++++++++++-
 tests/phpunit/PagedLanguagesTagsTest.php      | 174 ++++++++++++++++++
 6 files changed, 475 insertions(+), 62 deletions(-)
 create mode 100644 tests/phpunit/PagedLanguagesTagsTest.php

diff --git a/TODO.md b/TODO.md
index 3969074..ef3b562 100644
--- a/TODO.md
+++ b/TODO.md
@@ -51,6 +51,9 @@
 - [x] #fix-desync-deploy-code-exit-23 Fix desync: deploy-code exit-23 'Operation not permitted' — drop -p/-t (destination owned by www-data:xamxam, setgid; SSH user can't chmod), use -rlDz --size-only --context deploy
 - [x] #deploy-permissions-sudo-prompt-can-t deploy-permissions sudo prompt can't accept input: ssh -t drops pty when local stdin isn't a TTY. Add scoped NOPASSWD sudo drop-in (deploy/xamxam-fix-permissions.sudoers) + deploy-sudoers recipe and wire into deploy --context deploy
 - [x] #fix-raw-markdown-leaking Fix raw markdown leaking into TOC labels on licence/charte/about pages
+- [x] #rewrite-cc2r-checkbox-label Rewrite CC2r checkbox label to 'J'adhère au Collective Commitment to Reuse (CC2r)' (italic, both Libre and Interne branches)
+- [x] #fix-admin-contenus-page [!high] Fix admin contenus page slowdown: langues/mots-clés fragments ship 2.4MB HTML (737 tag rows + 217 lang rows, ~1960 inline SVG icons + per-row CSRF forms). Implement htmx infinite-scroll 'load more' (paged fragments via limit/offset) for both tables.
+- [x] #reduce-contenus-initial-page [!high] Reduce contenus initial page size from 100 to 25 rows per table (payload ~160KB total vs ~534KB)
 
 ## Deferred / Blocked
 - [ ] #just-setup-backs-a [!medium] just setup backs a stale setup-dev.sh (clones php-live-reload, legacy admin/data/ dirs) — needs rewrite or removal
diff --git a/app/public/admin/contenus-langues-fragment.php b/app/public/admin/contenus-langues-fragment.php
index 905683f..923c142 100644
--- a/app/public/admin/contenus-langues-fragment.php
+++ b/app/public/admin/contenus-langues-fragment.php
@@ -4,6 +4,15 @@
  *
  * HTMX fragment: returns the langues table for the contenus page,
  * optionally filtered by a search query.
+ *
+ * Infinite scroll: rows are served in pages of PAGE_SIZE. When there are
+ * more rows, a sentinel <tr> is emitted with hx-trigger="revealed": when it
+ * scrolls into view htmx fetches the next offset and swaps itself
+ * (outerHTML) with the next chunk of rows + a new sentinel. This keeps the
+ * initial payload small instead of shipping all languages at once.
+ *
+ * When $offset > 0 the fragment returns only the <tr> rows (append mode),
+ * because the sentinel lives inside the existing <tbody>.
  */
 require_once __DIR__ . '/../../bootstrap.php';
 require_once __DIR__ . '/../../src/AdminAuth.php';
@@ -15,14 +24,83 @@ if (empty($_SESSION['csrf_token'])) {
 
 require_once __DIR__ . '/../../src/Database.php';
 
+const LANGUES_PAGE_SIZE = 25;
+
 $searchQuery = trim($_GET['q'] ?? '');
+$offset      = max(0, (int) ($_GET['offset'] ?? 0));
 
 try {
-    $db = new Database();
-    $languages = ($searchQuery !== '') ? $db->searchLanguages($searchQuery) : $db->getAllLanguagesWithCount();
+    $db        = new Database();
+    $languages = $db->getLanguagesPage($searchQuery, LANGUES_PAGE_SIZE, $offset);
+    $total     = $db->countLanguagesWithCount($searchQuery);
 } catch (Exception $e) {
     die('<div class="flash-error">Erreur : ' . htmlspecialchars($e->getMessage()) . '</div>');
 }
+
+$hasMore   = ($offset + count($languages)) < $total;
+$nextUrl   = '/admin/contenus-langues-fragment.php?offset=' . ($offset + LANGUES_PAGE_SIZE)
+           . ($searchQuery !== '' ? '&q=' . urlencode($searchQuery) : '');
+
+/**
+ * Render one <tr> for a language row.
+ */
+function render_langue_row(array $lang): void
+{
+    ?>
+        <tr>
+            <td style="width:1%"><input type="checkbox" name="selected_langs[]" value="<?= (int)$lang['id'] ?>" onchange="languesUpdateBulk()"></td>
+            <td id="lang-name-<?= (int)$lang['id'] ?>" data-name="<?= htmlspecialchars($lang['name']) ?>">
+                <span class="tag-name-cell"><?= htmlspecialchars($lang['name']) ?></span>
+                <button type="button" class="admin-icon-btn admin-icon-btn--edit" title="Renommer"
+                        onclick="languesStartRename(<?= (int)$lang['id'] ?>)">
+                    <?= icon('pencil-note') ?>
+                </button>
+            </td>
+            <td class="admin-tags-count" style="width:1%;white-space:nowrap"><?= (int)$lang['thesis_count'] ?></td>
+            <td class="admin-actions-col" style="width:1%">
+                <div class="admin-actions">
+                    <form method="post" action="actions/language.php" class="admin-inline-form">
+                        <input type="hidden" name="csrf_token" value="<?= htmlspecialchars($_SESSION['csrf_token']) ?>">
+                        <input type="hidden" name="action" value="delete">
+                        <input type="hidden" name="return" value="/admin/contenus.php">
+                        <input type="hidden" name="language_id" value="<?= (int)$lang['id'] ?>">
+                        <button type="button" class="admin-icon-btn admin-icon-btn--delete" title="Supprimer"
+                                onclick="languesConfirmDelete(this, <?= htmlspecialchars(json_encode($lang['name']), ENT_QUOTES) ?>)">
+                            <?= icon('trash') ?>
+                        </button>
+                    </form>
+                </div>
+            </td>
+        </tr>
+    <?php
+}
+
+/**
+ * Render the "load more" sentinel row (or nothing when exhausted).
+ */
+function render_langues_sentinel(bool $hasMore, string $nextUrl): void
+{
+    if (!$hasMore) {
+        return;
+    }
+    ?>
+        <tr class="admin-load-more" hx-get="<?= htmlspecialchars($nextUrl) ?>"
+            hx-trigger="intersect once root:#langues-table-wrap" hx-swap="outerHTML" hx-target="this">
+            <td colspan="4" class="admin-load-more__cell">Chargement…</td>
+        </tr>
+    <?php
+}
+
+// ── Append mode: only the rows, swapped in place of the sentinel ──────────
+if ($offset > 0) {
+    foreach ($languages as $lang) {
+        render_langue_row($lang);
+    }
+    render_langues_sentinel($hasMore, $nextUrl);
+    return;
+}
+
+// ── Initial load: full wrapper ────────────────────────────────────────────
 ?>
 <div id="langues-bulk-actions" class="admin-bulk-actions" style="display:none;position:sticky;top:0;z-index:10">
     <strong><span id="langues-selected-count">0</span> langue(s) sélectionnée(s)</strong>
@@ -68,32 +146,9 @@ try {
         <tr><td colspan="4" class="admin-empty">Aucune langue trouvée.</td></tr>
         <?php else: ?>
         <?php foreach ($languages as $lang): ?>
-        <tr>
-            <td style="width:1%"><input type="checkbox" name="selected_langs[]" value="<?= (int)$lang['id'] ?>" onchange="languesUpdateBulk()"></td>
-            <td id="lang-name-<?= (int)$lang['id'] ?>" data-name="<?= htmlspecialchars($lang['name']) ?>">
-                <span class="tag-name-cell"><?= htmlspecialchars($lang['name']) ?></span>
-                <button type="button" class="admin-icon-btn admin-icon-btn--edit" title="Renommer"
-                        onclick="languesStartRename(<?= (int)$lang['id'] ?>)">
-                    <?= icon('pencil-note') ?>
-                </button>
-            </td>
-            <td class="admin-tags-count" style="width:1%;white-space:nowrap"><?= (int)$lang['thesis_count'] ?></td>
-            <td class="admin-actions-col" style="width:1%">
-                <div class="admin-actions">
-                    <form method="post" action="actions/language.php" class="admin-inline-form">
-                        <input type="hidden" name="csrf_token" value="<?= htmlspecialchars($_SESSION['csrf_token']) ?>">
-                        <input type="hidden" name="action" value="delete">
-                        <input type="hidden" name="return" value="/admin/contenus.php">
-                        <input type="hidden" name="language_id" value="<?= (int)$lang['id'] ?>">
-                        <button type="button" class="admin-icon-btn admin-icon-btn--delete" title="Supprimer"
-                                onclick="languesConfirmDelete(this, <?= htmlspecialchars(json_encode($lang['name']), ENT_QUOTES) ?>)">
-                            <?= icon('trash') ?>
-                        </button>
-                    </form>
-                </div>
-            </td>
-        </tr>
+        <?php render_langue_row($lang); ?>
         <?php endforeach; ?>
+        <?php render_langues_sentinel($hasMore, $nextUrl); ?>
         <?php endif; ?>
     </tbody>
 </table>
diff --git a/app/public/admin/contenus-motscles-fragment.php b/app/public/admin/contenus-motscles-fragment.php
index d9aba9f..b620f8c 100644
--- a/app/public/admin/contenus-motscles-fragment.php
+++ b/app/public/admin/contenus-motscles-fragment.php
@@ -4,6 +4,15 @@
  *
  * HTMX fragment: returns the mots-clés table for the contenus page,
  * optionally filtered by a search query.
+ *
+ * Infinite scroll: rows are served in pages of PAGE_SIZE. When there are
+ * more rows, a sentinel <tr> is emitted with hx-trigger="revealed": when it
+ * scrolls into view htmx fetches the next offset and swaps itself
+ * (outerHTML) with the next chunk of rows + a new sentinel. This keeps the
+ * initial payload small instead of shipping all tags at once.
+ *
+ * When $offset > 0 the fragment returns only the <tr> rows (append mode),
+ * because the sentinel lives inside the existing <tbody>.
  */
 require_once __DIR__ . '/../../bootstrap.php';
 require_once __DIR__ . '/../../src/AdminAuth.php';
@@ -15,14 +24,83 @@ if (empty($_SESSION['csrf_token'])) {
 
 require_once __DIR__ . '/../../src/Database.php';
 
+const MOTSCLES_PAGE_SIZE = 25;
+
 $searchQuery = trim($_GET['q'] ?? '');
+$offset      = max(0, (int) ($_GET['offset'] ?? 0));
 
 try {
-    $db   = new Database();
-    $tags = ($searchQuery !== '') ? $db->searchTags($searchQuery) : $db->getAllTagsWithCount();
+    $db    = new Database();
+    $tags  = $db->getTagsPage($searchQuery, MOTSCLES_PAGE_SIZE, $offset);
+    $total = $db->countTagsWithCount($searchQuery);
 } catch (Exception $e) {
     die('<div class="flash-error">Erreur : ' . htmlspecialchars($e->getMessage()) . '</div>');
 }
+
+$hasMore = ($offset + count($tags)) < $total;
+$nextUrl = '/admin/contenus-motscles-fragment.php?offset=' . ($offset + MOTSCLES_PAGE_SIZE)
+         . ($searchQuery !== '' ? '&q=' . urlencode($searchQuery) : '');
+
+/**
+ * Render one <tr> for a tag row.
+ */
+function render_motscles_row(array $tag): void
+{
+    ?>
+        <tr>
+            <td style="width:1%"><input type="checkbox" name="selected_tags[]" value="<?= (int)$tag['id'] ?>" onchange="motsclesUpdateBulk()"></td>
+            <td id="motscles-name-<?= (int)$tag['id'] ?>" data-name="<?= htmlspecialchars($tag['name']) ?>">
+                <span class="tag-name-cell"><?= htmlspecialchars($tag['name']) ?></span>
+                <button type="button" class="admin-icon-btn admin-icon-btn--edit" title="Renommer"
+                        onclick="motsclesStartRename(<?= (int)$tag['id'] ?>)">
+                    <?= icon('pencil-note') ?>
+                </button>
+            </td>
+            <td class="admin-tags-count" style="width:1%;white-space:nowrap"><?= (int)$tag['thesis_count'] ?></td>
+            <td class="admin-actions-col" style="width:1%">
+                <div class="admin-actions">
+                    <form method="post" action="actions/tag.php" class="admin-inline-form">
+                        <input type="hidden" name="csrf_token" value="<?= htmlspecialchars($_SESSION['csrf_token']) ?>">
+                        <input type="hidden" name="action" value="delete">
+                        <input type="hidden" name="return" value="/admin/contenus.php">
+                        <input type="hidden" name="tag_id" value="<?= (int)$tag['id'] ?>">
+                        <button type="button" class="admin-icon-btn admin-icon-btn--delete" title="Supprimer"
+                                onclick="motsclesConfirmDelete(this, <?= htmlspecialchars(json_encode($tag['name']), ENT_QUOTES) ?>)">
+                            <?= icon('trash') ?>
+                        </button>
+                    </form>
+                </div>
+            </td>
+        </tr>
+    <?php
+}
+
+/**
+ * Render the "load more" sentinel row (or nothing when exhausted).
+ */
+function render_motscles_sentinel(bool $hasMore, string $nextUrl): void
+{
+    if (!$hasMore) {
+        return;
+    }
+    ?>
+        <tr class="admin-load-more" hx-get="<?= htmlspecialchars($nextUrl) ?>"
+            hx-trigger="intersect once root:#motscles-table-wrap" hx-swap="outerHTML" hx-target="this">
+            <td colspan="4" class="admin-load-more__cell">Chargement…</td>
+        </tr>
+    <?php
+}
+
+// ── Append mode: only the rows, swapped in place of the sentinel ──────────
+if ($offset > 0) {
+    foreach ($tags as $tag) {
+        render_motscles_row($tag);
+    }
+    render_motscles_sentinel($hasMore, $nextUrl);
+    return;
+}
+
+// ── Initial load: full wrapper ────────────────────────────────────────────
 ?>
 <div id="motscles-bulk-actions" class="admin-bulk-actions" style="display:none;position:sticky;top:0;z-index:10">
     <strong><span id="motscles-selected-count">0</span> mot(s)-clé(s) sélectionné(s)</strong>
@@ -68,32 +146,9 @@ try {
         <tr><td colspan="4" class="admin-empty">Aucun mot-clé trouvé.</td></tr>
         <?php else: ?>
         <?php foreach ($tags as $tag): ?>
-        <tr>
-            <td style="width:1%"><input type="checkbox" name="selected_tags[]" value="<?= (int)$tag['id'] ?>" onchange="motsclesUpdateBulk()"></td>
-            <td id="motscles-name-<?= (int)$tag['id'] ?>" data-name="<?= htmlspecialchars($tag['name']) ?>">
-                <span class="tag-name-cell"><?= htmlspecialchars($tag['name']) ?></span>
-                <button type="button" class="admin-icon-btn admin-icon-btn--edit" title="Renommer"
-                        onclick="motsclesStartRename(<?= (int)$tag['id'] ?>)">
-                    <?= icon('pencil-note') ?>
-                </button>
-            </td>
-            <td class="admin-tags-count" style="width:1%;white-space:nowrap"><?= (int)$tag['thesis_count'] ?></td>
-            <td class="admin-actions-col" style="width:1%">
-                <div class="admin-actions">
-                    <form method="post" action="actions/tag.php" class="admin-inline-form">
-                        <input type="hidden" name="csrf_token" value="<?= htmlspecialchars($_SESSION['csrf_token']) ?>">
-                        <input type="hidden" name="action" value="delete">
-                        <input type="hidden" name="return" value="/admin/contenus.php">
-                        <input type="hidden" name="tag_id" value="<?= (int)$tag['id'] ?>">
-                        <button type="button" class="admin-icon-btn admin-icon-btn--delete" title="Supprimer"
-                                onclick="motsclesConfirmDelete(this, <?= htmlspecialchars(json_encode($tag['name']), ENT_QUOTES) ?>)">
-                            <?= icon('trash') ?>
-                        </button>
-                    </form>
-                </div>
-            </td>
-        </tr>
+        <?php render_motscles_row($tag); ?>
         <?php endforeach; ?>
+        <?php render_motscles_sentinel($hasMore, $nextUrl); ?>
         <?php endif; ?>
     </tbody>
 </table>
diff --git a/app/public/assets/css/admin.css b/app/public/assets/css/admin.css
index 2321201..cfa1f5f 100644
--- a/app/public/assets/css/admin.css
+++ b/app/public/assets/css/admin.css
@@ -255,6 +255,22 @@
   text-align: center;
 }
 
+/* "Load more" sentinel row for infinite-scroll admin tables (contenus).
+   Sits at the bottom of the <tbody>; htmx replaces it with the next page
+   of rows when it scrolls into the table's viewport. */
+.admin-load-more__cell {
+  color: var(--text-tertiary);
+  padding: var(--space-s) var(--space-2xs);
+  text-align: center;
+  font-size: var(--step--1);
+}
+
+/* Fade the sentinel out once its request is in flight so it does not
+   visually "stick" while the next page is fetched. */
+.admin-load-more.htmx-request .admin-load-more__cell {
+  opacity: 0.4;
+}
+
 /* Identifier column in the thesis table */
 .admin-table-id {
   color: var(--text-secondary);
diff --git a/app/src/Database.php b/app/src/Database.php
index f357a57..0c9abe5 100644
--- a/app/src/Database.php
+++ b/app/src/Database.php
@@ -1390,11 +1390,41 @@ class Database
     }
 
     /**
-     * Return all tags with a count of associated (published) theses.
+     * Paged tag listing used by the admin contenus "load more" fragment.
+     * Same ordering as getAllTagsWithCount(); $query filters by name prefix.
      */
-    public function getAllTagsWithCount(): array
+    public function getTagsPage(string $query = '', int $limit = 100, int $offset = 0): array
     {
-        $stmt = $this->pdo->query('
+        $query = trim($query);
+        $sql = '
+            SELECT tg.id, tg.name,
+                   COUNT(DISTINCT t.id) as thesis_count
+            FROM tags tg
+            LEFT JOIN thesis_tags tt ON tg.id = tt.tag_id
+            LEFT JOIN theses t ON tt.thesis_id = t.id AND t.deleted_at IS NULL
+            WHERE tg.deleted_at IS NULL';
+        $params = [];
+        if ($query !== '') {
+            $sql .= ' AND tg.name LIKE ?';
+            $params[] = $query . '%';
+        }
+        $sql .= ' GROUP BY tg.id ORDER BY tg.name COLLATE NOCASE LIMIT ? OFFSET ?';
+        $params[] = $limit;
+        $params[] = $offset;
+        $stmt = $this->pdo->prepare($sql);
+        $stmt->execute($params);
+        return $stmt->fetchAll();
+    }
+
+    /**
+     * Return all tags with a count of associated (published) theses.
+     *
+     * @param int|null $limit  Optional page size (for htmx infinite scroll).
+     * @param int      $offset Row offset when $limit is set.
+     */
+    public function getAllTagsWithCount(?int $limit = null, int $offset = 0): array
+    {
+        $sql = '
             SELECT tg.id, tg.name,
                    COUNT(DISTINCT t.id) as thesis_count
             FROM tags tg
@@ -1403,8 +1433,32 @@ class Database
             WHERE tg.deleted_at IS NULL
             GROUP BY tg.id
             ORDER BY tg.name COLLATE NOCASE
-        ');
-        return $stmt->fetchAll();
+        ';
+        if ($limit !== null) {
+            $stmt = $this->pdo->prepare($sql . ' LIMIT ? OFFSET ?');
+            $stmt->execute([$limit, $offset]);
+            return $stmt->fetchAll();
+        }
+        return $this->pdo->query($sql)->fetchAll();
+    }
+
+    /**
+     * Count tags matching an optional name prefix (used to know when the
+     * infinite-scroll page has reached the end).
+     */
+    public function countTagsWithCount(string $query = ''): int
+    {
+        $query = trim($query);
+        if ($query === '') {
+            return (int) $this->pdo->query(
+                'SELECT COUNT(*) FROM tags WHERE deleted_at IS NULL'
+            )->fetchColumn();
+        }
+        $stmt = $this->pdo->prepare(
+            'SELECT COUNT(*) FROM tags WHERE name LIKE ? AND deleted_at IS NULL'
+        );
+        $stmt->execute([$query . '%']);
+        return (int) $stmt->fetchColumn();
     }
 
     /**
@@ -1514,11 +1568,14 @@ class Database
 
     /**
      * Return all languages with a count of associated theses.
+     *
+     * @param int|null $limit  Optional page size (for htmx infinite scroll).
+     * @param int      $offset Row offset when $limit is set.
      */
-    public function getAllLanguagesWithCount(): array
+    public function getAllLanguagesWithCount(?int $limit = null, int $offset = 0): array
     {
         // Group by lowercased name to deduplicate, keeping the first id
-        $stmt = $this->pdo->query('
+        $sql = '
             SELECT MIN(l.id) as id,
                    UPPER(SUBSTR(MIN(l.name),1,1)) || SUBSTR(MIN(l.name),2) as name,
                    COUNT(DISTINCT t.id) as thesis_count
@@ -1528,7 +1585,60 @@ class Database
             WHERE l.deleted_at IS NULL
             GROUP BY LOWER(l.name)
             ORDER BY LOWER(MIN(l.name)) COLLATE NOCASE
-        ');
+        ';
+        if ($limit !== null) {
+            $stmt = $this->pdo->prepare($sql . ' LIMIT ? OFFSET ?');
+            $stmt->execute([$limit, $offset]);
+            return $stmt->fetchAll();
+        }
+        return $this->pdo->query($sql)->fetchAll();
+    }
+
+    /**
+     * Count distinct languages matching an optional name prefix (used to know
+     * when the infinite-scroll page has reached the end).
+     */
+    public function countLanguagesWithCount(string $query = ''): int
+    {
+        $query = trim($query);
+        if ($query === '') {
+            return (int) $this->pdo->query(
+                'SELECT COUNT(DISTINCT LOWER(name)) FROM languages WHERE deleted_at IS NULL'
+            )->fetchColumn();
+        }
+        $stmt = $this->pdo->prepare(
+            'SELECT COUNT(DISTINCT LOWER(name)) FROM languages WHERE LOWER(name) LIKE LOWER(?) AND deleted_at IS NULL'
+        );
+        $stmt->execute([$query . '%']);
+        return (int) $stmt->fetchColumn();
+    }
+
+    /**
+     * Paged language listing used by the admin contenus "load more" fragment.
+     * Same ordering/dedup as getAllLanguagesWithCount(); $query filters by
+     * name prefix.
+     */
+    public function getLanguagesPage(string $query = '', int $limit = 100, int $offset = 0): array
+    {
+        $query = trim($query);
+        $sql = '
+            SELECT MIN(l.id) as id,
+                   UPPER(SUBSTR(MIN(l.name),1,1)) || SUBSTR(MIN(l.name),2) as name,
+                   COUNT(DISTINCT t.id) as thesis_count
+            FROM languages l
+            LEFT JOIN thesis_languages tl ON l.id = tl.language_id
+            LEFT JOIN theses t ON tl.thesis_id = t.id AND t.deleted_at IS NULL
+            WHERE l.deleted_at IS NULL';
+        $params = [];
+        if ($query !== '') {
+            $sql .= ' AND LOWER(l.name) LIKE LOWER(?)';
+            $params[] = $query . '%';
+        }
+        $sql .= ' GROUP BY LOWER(l.name) ORDER BY LOWER(MIN(l.name)) COLLATE NOCASE LIMIT ? OFFSET ?';
+        $params[] = $limit;
+        $params[] = $offset;
+        $stmt = $this->pdo->prepare($sql);
+        $stmt->execute($params);
         return $stmt->fetchAll();
     }
 
diff --git a/tests/phpunit/PagedLanguagesTagsTest.php b/tests/phpunit/PagedLanguagesTagsTest.php
new file mode 100644
index 0000000..2a3e2f0
--- /dev/null
+++ b/tests/phpunit/PagedLanguagesTagsTest.php
@@ -0,0 +1,174 @@
+<?php
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * PagedLanguagesTagsTest — covers the paged lookups that back the admin
+ * contenus page "load more" infinite scroll (getTagsPage / getLanguagesPage
+ * plus their count helpers and the optional limit/offset on the unpaged
+ * variants).
+ */
+class PagedLanguagesTagsTest extends TestCase
+{
+    private Database $db;
+
+    protected function setUp(): void
+    {
+        TestDatabase::resetData();
+        $this->db = TestDatabase::getInstance();
+    }
+
+    protected function tearDown(): void
+    {
+        // Languages are seeded by the schema and not cleared by resetData(),
+        // so remove the test-specific rows we inserted.
+        TestDatabase::getPDO()
+            ->exec("DELETE FROM languages WHERE name LIKE 'PagLang%'");
+    }
+
+    private function seedTags(array $names): void
+    {
+        $pdo = TestDatabase::getPDO();
+        $stmt = $pdo->prepare('INSERT INTO tags (name) VALUES (?)');
+        foreach ($names as $n) {
+            $stmt->execute([$n]);
+        }
+    }
+
+    private function seedLanguages(array $names): void
+    {
+        $pdo = TestDatabase::getPDO();
+        $stmt = $pdo->prepare('INSERT INTO languages (name) VALUES (?)');
+        foreach ($names as $n) {
+            $stmt->execute([$n]);
+        }
+    }
+
+    // ── Tags ──────────────────────────────────────────────────────────────
+
+    public function testGetTagsPageRespectsLimitAndOffset(): void
+    {
+        $this->seedTags(['alpha', 'bravo', 'charlie', 'delta', 'echo']);
+
+        $page1 = $this->db->getTagsPage('', 2, 0);
+        $page2 = $this->db->getTagsPage('', 2, 2);
+        $page3 = $this->db->getTagsPage('', 2, 4);
+
+        $this->assertSame(['alpha', 'bravo'], array_column($page1, 'name'));
+        $this->assertSame(['charlie', 'delta'], array_column($page2, 'name'));
+        $this->assertSame(['echo'], array_column($page3, 'name'));
+    }
+
+    public function testGetTagsPageFiltersByPrefix(): void
+    {
+        $this->seedTags(['alpha', 'alpine', 'bravo']);
+
+        $rows = $this->db->getTagsPage('al', 100, 0);
+
+        $this->assertSame(['alpha', 'alpine'], array_column($rows, 'name'));
+    }
+
+    public function testCountTagsWithCount(): void
+    {
+        $this->seedTags(['alpha', 'alpine', 'bravo']);
+
+        $this->assertSame(3, $this->db->countTagsWithCount(''));
+        $this->assertSame(2, $this->db->countTagsWithCount('al'));
+        $this->assertSame(0, $this->db->countTagsWithCount('zzz'));
+    }
+
+    public function testCountTagsIgnoresSoftDeleted(): void
+    {
+        $this->seedTags(['alpha', 'bravo']);
+        $id = (int) TestDatabase::getPDO()
+            ->query("SELECT id FROM tags WHERE name = 'bravo'")->fetchColumn();
+        $this->db->deleteTag($id);
+
+        $this->assertSame(1, $this->db->countTagsWithCount(''));
+        $this->assertSame(['alpha'], array_column($this->db->getTagsPage('', 100, 0), 'name'));
+    }
+
+    public function testGetAllTagsWithCountOptionalPaging(): void
+    {
+        $this->seedTags(['alpha', 'bravo', 'charlie']);
+
+        $this->assertCount(3, $this->db->getAllTagsWithCount());
+        $this->assertSame(
+            ['alpha', 'bravo'],
+            array_column($this->db->getAllTagsWithCount(2, 0), 'name')
+        );
+        $this->assertSame(
+            ['charlie'],
+            array_column($this->db->getAllTagsWithCount(2, 2), 'name')
+        );
+    }
+
+    // ── Languages ─────────────────────────────────────────────────────────
+
+    /**
+     * The schema seeds a few languages, so language tests must not assume an
+     * empty table. Query a unique prefix ("PagLang") and account for the
+     * seeded rows in the unpaged assertions.
+     */
+    public function testGetLanguagesPageRespectsLimitAndOffset(): void
+    {
+        $this->seedLanguages(['PagLang A', 'PagLang B', 'PagLang C', 'PagLang D']);
+
+        $this->assertSame(
+            ['PagLang A', 'PagLang B'],
+            array_column($this->db->getLanguagesPage('PagLang', 2, 0), 'name')
+        );
+        $this->assertSame(
+            ['PagLang C', 'PagLang D'],
+            array_column($this->db->getLanguagesPage('PagLang', 2, 2), 'name')
+        );
+    }
+
+    public function testGetLanguagesPageDeduplicatesCaseInsensitively(): void
+    {
+        $this->seedLanguages(['PagLangDup', 'paglanguedup']);
+
+        // Grouped by LOWER(name): two distinct lowercase names.
+        $names = array_column($this->db->getLanguagesPage('PagLang', 100, 0), 'name');
+        $lowered = array_map('strtolower', $names);
+
+        $this->assertSame(['paglangdup', 'paglanguedup'], $lowered);
+        $this->assertSame(2, $this->db->countLanguagesWithCount('PagLang'));
+    }
+
+    public function testGetLanguagesPageFiltersCaseInsensitively(): void
+    {
+        $this->seedLanguages(['PagLangX', 'PagLangY']);
+
+        // Lowercase query must still match the capitalised names.
+        $rows = $this->db->getLanguagesPage('pagl', 100, 0);
+
+        $this->assertSame(['PagLangX', 'PagLangY'], array_column($rows, 'name'));
+    }
+
+    public function testCountLanguagesWithCount(): void
+    {
+        $this->seedLanguages(['PagLangA', 'PagLangB', 'PagLangC']);
+
+        $this->assertSame(3, $this->db->countLanguagesWithCount('PagLang'));
+        $this->assertSame(1, $this->db->countLanguagesWithCount('PagLangA'));
+        $this->assertSame(0, $this->db->countLanguagesWithCount('zzz'));
+    }
+
+    public function testGetAllLanguagesWithCountOptionalPaging(): void
+    {
+        $this->seedLanguages(['PagLangA', 'PagLangB', 'PagLangC']);
+
+        $unpaged = array_map('strtolower', array_column($this->db->getAllLanguagesWithCount(), 'name'));
+        $this->assertContains('paglanga', $unpaged);
+        $this->assertContains('paglangb', $unpaged);
+        $this->assertContains('paglangc', $unpaged);
+
+        $page1 = array_column($this->db->getAllLanguagesWithCount(2, 0), 'name');
+        $page2 = array_column($this->db->getAllLanguagesWithCount(2, 2), 'name');
+        $this->assertCount(2, $page1);
+        $this->assertCount(2, $page2);
+        // Pages must not overlap.
+        $this->assertSame([], array_intersect($page1, $page2));
+    }
+}