<?php
/**
 * PeerTube video relink endpoint (admin).
 *
 * POST /admin/actions/peertube-relink.php
 * Body: JSON { thesis_id: 123, uuid: "bmpQZTUPv4ou8ufiwajV63" }
 *
 * Links an existing PeerTube video to a thesis by inserting a thesis_files row
 * with file_path = 'peertube_ids:{uuid}'. Only videos that are on the channel
 * but NOT linked to any TFE can be relinked.
 */
require_once __DIR__ . '/../../../bootstrap.php';
require_once __DIR__ . '/../../../src/AdminAuth.php';
AdminAuth::requireLogin();

function peertubeRelinkError(int $code, string $message): never {
    http_response_code($code);
    header('Content-Type: application/json');
    echo json_encode(['ok' => false, 'error' => $message]);
    exit;
}

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    peertubeRelinkError(405, 'Méthode non autorisée.');
}

$csrfHeader = $_SERVER['HTTP_X_CSRF_TOKEN'] ?? '';
if (!isset($_SESSION['csrf_token'])
    || !hash_equals($_SESSION['csrf_token'], $csrfHeader)) {
    peertubeRelinkError(403, 'Token CSRF invalide.');
}

$body = json_decode(file_get_contents('php://input'), true);
if (!is_array($body)) {
    peertubeRelinkError(400, 'JSON invalide.');
}

$thesisId = filter_var($body['thesis_id'] ?? '', FILTER_VALIDATE_INT);
$uuid     = trim($body['uuid'] ?? '');

if (!$thesisId || $uuid === '') {
    peertubeRelinkError(400, 'Paramètres invalides (thesis_id + uuid requis).');
}

// Validate UUID format (shortUUID or full UUID)
if (!preg_match('/^[a-zA-Z0-9\-_]+$/', $uuid)) {
    peertubeRelinkError(400, 'UUID invalide.');
}

require_once APP_ROOT . '/src/Database.php';
require_once APP_ROOT . '/src/PeerTubeService.php';

$db = new Database();

if (!PeerTubeService::isConfigured($db)) {
    peertubeRelinkError(503, 'PeerTube non configuré.');
}

// Check thesis exists
$thesis = $db->getThesis($thesisId);
if (!$thesis) {
    peertubeRelinkError(404, 'TFE introuvable.');
}

// Check this UUID is not already linked to this thesis
$pdo = $db->getConnection();
$stmt = $pdo->prepare(
    "SELECT id FROM thesis_files
     WHERE thesis_id = ? AND file_path = ?"
);
$stmt->execute([$thesisId, 'peertube_ids:' . $uuid]);
if ($stmt->fetch()) {
    peertubeRelinkError(409, 'Cette vidéo est déjà liée à ce TFE.');
}

// Verify the video exists on the channel
$info = PeerTubeService::fetchVideoInfo($db, $uuid);
if ($info === null) {
    peertubeRelinkError(404, 'Vidéo introuvable sur PeerTube.');
}

// Verify it's not already linked to another TFE
$stmt = $pdo->prepare(
    "SELECT t.identifier FROM thesis_files tf
     JOIN theses t ON t.id = tf.thesis_id
     WHERE tf.file_path = ? AND t.deleted_at IS NULL"
);
$stmt->execute(['peertube_ids:' . $uuid]);
$existing = $stmt->fetch();
if ($existing) {
    peertubeRelinkError(409,
        'Cette vidéo est déjà liée au TFE ' . htmlspecialchars($existing['identifier'] ?? '?')
        . '. Dé-liez-la d\'abord avant de la relier à un autre.'
    );
}

// Determine file type from PeerTube info
$videoName = $info['name'] ?? $uuid;
$fileType  = 'video'; // default
$catId     = (int)($info['category']['id'] ?? 0);
if ($catId === 16) {
    $fileType = 'audio';
}

$db->insertThesisFile(
    $thesisId,
    $fileType,
    'peertube_ids:' . $uuid,
    $videoName,
    0,                // size unknown (not on disk)
    'video/mp4',      // PeerTube streams HLS, mime is nominal
    null,
    null
);

$newId = $pdo->lastInsertId();

error_log("[peertube-relink] thesis_id=$thesisId uuid=$uuid file_type=$fileType new_id=$newId");

header('Content-Type: application/json');
echo json_encode([
    'ok'      => true,
    'id'      => (int)$newId,
    'message' => 'Vidéo PeerTube reliée avec succès.',
]);
exit;