<?php
require __DIR__ . '/../../bbs/db_conn.php';
header('Content-Type: application/json; charset=utf-8');

// PDO 연결 생성
$pdo = db_conn();

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    echo json_encode(['success' => false, 'message' => 'Invalid request']);
    exit;
}

$content_id = isset($_POST['content_id']) ? trim($_POST['content_id']) : '';
$keywords_csv = isset($_POST['keywords']) ? trim($_POST['keywords']) : '';
$admin_id = 'admin'; // User login ID not provided in context, defaulting to 'admin'

if ($content_id === '') {
    echo json_encode(['success' => false, 'message' => 'missing content_id']);
    exit;
}

try {
    $pdo->beginTransaction();

    // Set all existing active keywords to inactive first
    $updateStmt = $pdo->prepare("UPDATE edu_content_keywords SET is_active='0', updated_at=NOW(), updated_by=:admin WHERE content_id=:c AND is_active='1'");
    $updateStmt->execute([':c' => $content_id, ':admin' => $admin_id]);

    if ($keywords_csv !== '') {
        $keywords = explode(',', $keywords_csv);
        $insertStmt = $pdo->prepare("INSERT INTO edu_content_keywords (content_id, keyword_code, is_active, created_by, created_at, updated_by, updated_at) 
                                 VALUES (:c, :k, '1', :admin1, NOW(), :admin2, NOW()) 
                                 ON DUPLICATE KEY UPDATE is_active='1', updated_by=:admin3, updated_at=NOW()");
        foreach ($keywords as $k) {
            $k = trim($k);
            if ($k !== '') {
                $insertStmt->execute([
                    ':c' => $content_id,
                    ':k' => $k,
                    ':admin1' => $admin_id,
                    ':admin2' => $admin_id,
                    ':admin3' => $admin_id
                ]);
            }
        }
    }

    $pdo->commit();
    echo json_encode(['success' => true]);
} catch (Exception $e) {
    $pdo->rollBack();
    echo json_encode(['success' => false, 'message' => $e->getMessage()]);
}