<?php
/**
 * Restore a trashed file back to its original location (admin).
 *
 * POST /admin/actions/restore-trash.php
 * Body: trash_file=123_filename.pdf
 *
 * Reads the JSON sidecar file (trash_file.json) to get the original
 * thesis_files row metadata, re-inserts the DB row, and moves the file
 * back from tmp/_trash to its original storage path.
 */

require_once __DIR__ . '/../../../bootstrap.php';
require_once __DIR__ . '/../../../src/AdminAuth.php';

AdminAuth::requireLogin();

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    http_response_code(405);
    header('Content-Type: application/json; charset=utf-8');
    echo json_encode(['ok' => false, 'error' => 'Méthode non autorisée.']);
    exit;
}

if (!isset($_POST['csrf_token'], $_SESSION['csrf_token'])
    || !hash_equals($_SESSION['csrf_token'], $_POST['csrf_token'])) {
    http_response_code(403);
    header('Content-Type: application/json; charset=utf-8');
    echo json_encode(['ok' => false, 'error' => 'CSRF invalide.']);
    exit;
}

$trashFile = trim($_POST['trash_file'] ?? '');
if ($trashFile === '') {
    http_response_code(400);
    header('Content-Type: application/json; charset=utf-8');
    echo json_encode(['ok' => false, 'error' => 'Nom de fichier invalide.']);
    exit;
}

$storageRoot = STORAGE_ROOT;
$trashDir    = $storageRoot . '/tmp/_trash';
$trashPath   = $trashDir . '/' . basename($trashFile);
$sidecarPath = $trashPath . '.json';

// Validate the trash file is inside the trash directory
if (!is_file($trashPath) || !str_starts_with(realpath($trashPath), realpath($trashDir))) {
    http_response_code(404);
    header('Content-Type: application/json; charset=utf-8');
    echo json_encode(['ok' => false, 'error' => 'Fichier introuvable dans la corbeille.']);
    exit;
}

// Read sidecar metadata
if (!file_exists($sidecarPath)) {
    http_response_code(400);
    header('Content-Type: application/json; charset=utf-8');
    echo json_encode([
        'ok' => false,
        'error' => 'Métadonnées de restauration absentes (fichier trop ancien ?). Utilisez "Relier un fichier existant".',
    ]);
    exit;
}

$sidecar = json_decode(file_get_contents($sidecarPath), true);
if (!is_array($sidecar) || empty($sidecar['file_path']) || empty($sidecar['thesis_id'])) {
    http_response_code(400);
    header('Content-Type: application/json; charset=utf-8');
    echo json_encode(['ok' => false, 'error' => 'Métadonnées corrompues.']);
    exit;
}

$originalPath = $sidecar['file_path'];
$thesisId     = (int)$sidecar['thesis_id'];
$fileType     = $sidecar['file_type'] ?? 'other';
$fileName     = $sidecar['file_name'] ?? basename($originalPath);
$mimeType     = $sidecar['mime_type'] ?? 'application/octet-stream';
$fileSize     = (int)($sidecar['file_size'] ?? 0);
$displayLabel = $sidecar['display_label'] ?? null;

// Verify the thesis still exists
require_once __DIR__ . '/../../../src/Database.php';
$db = new Database();
$thesis = $db->getThesis($thesisId);
if (!$thesis) {
    http_response_code(404);
    header('Content-Type: application/json; charset=utf-8');
    echo json_encode(['ok' => false, 'error' => 'Le TFE associé n\'existe plus.']);
    exit;
}

// Check no file already exists at the original path
$absOriginal = $storageRoot . '/' . $originalPath;
if (file_exists($absOriginal)) {
    // File already restored or a new file replaced it — just clean up the trash
    @unlink($trashPath);
    @unlink($sidecarPath);
    http_response_code(409);
    header('Content-Type: application/json; charset=utf-8');
    echo json_encode([
        'ok' => false,
        'error' => 'Un fichier existe déjà à l\'emplacement d\'origine. Fichier corbeille nettoyé.',
    ]);
    exit;
}

// Ensure parent directory exists
$parentDir = dirname($absOriginal);
if (!is_dir($parentDir)) {
    mkdir($parentDir, 0755, true);
}

// Move file back from trash to original location
if (!rename($trashPath, $absOriginal)) {
    http_response_code(500);
    header('Content-Type: application/json; charset=utf-8');
    echo json_encode(['ok' => false, 'error' => 'Échec du déplacement du fichier.']);
    exit;
}
chmod($absOriginal, 0644);

// Delete the sidecar file
@unlink($sidecarPath);

// Re-insert the thesis_files DB row
$db->insertThesisFile(
    $thesisId,
    $fileType,
    $originalPath,
    $fileName,
    $fileSize,
    $mimeType,
    $displayLabel,
    null
);

$newId = $db->getConnection()->lastInsertId();

error_log("[restore-trash] thesis_id=$thesisId file_id=$newId restored from trash: $trashFile → $originalPath");

$_SESSION['csrf_token'] = bin2hex(random_bytes(32));

// HTMX request: re-render the fragment
if (isset($_SERVER['HTTP_HX_REQUEST'])) {
    header('HX-Trigger: refreshStats');
    require __DIR__ . '/cleanup-stats-fragment.php';
    exit;
}

header('Content-Type: application/json; charset=utf-8');
echo json_encode([
    'ok'       => true,
    'id'       => $newId,
    'thesis_id' => $thesisId,
    'message'  => 'Fichier restauré avec succès.',
]);
exit;