<?php
declare(strict_types=1);

require_once __DIR__ . '/../db/config.php';

@date_default_timezone_set('UTC');
if (session_status() !== PHP_SESSION_ACTIVE) {
    session_start();
}

function h(string $value): string
{
    return htmlspecialchars($value, ENT_QUOTES, 'UTF-8');
}

function ensure_tables(): void
{
    $pdo = db();
    $pdo->exec(
        "CREATE TABLE IF NOT EXISTS stores (
            id INT AUTO_INCREMENT PRIMARY KEY,
            name VARCHAR(150) NOT NULL,
            slug VARCHAR(150) NOT NULL,
            contact_email VARCHAR(190) DEFAULT NULL,
            currency CHAR(3) NOT NULL DEFAULT 'USD',
            created_at DATETIME NOT NULL
        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4"
    );

    $pdo->exec(
        "CREATE TABLE IF NOT EXISTS products (
            id INT AUTO_INCREMENT PRIMARY KEY,
            store_id INT NOT NULL,
            sku VARCHAR(64) NOT NULL,
            name VARCHAR(180) NOT NULL,
            price DECIMAL(10,2) NOT NULL DEFAULT 0.00,
            stock INT NOT NULL DEFAULT 0,
            status VARCHAR(24) NOT NULL DEFAULT 'active',
            created_at DATETIME NOT NULL,
            INDEX (store_id)
        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4"
    );
}

function slugify(string $value): string
{
    $slug = strtolower(trim($value));
    $slug = preg_replace('/[^a-z0-9]+/', '-', $slug) ?? '';
    $slug = trim($slug, '-');
    return $slug !== '' ? $slug : 'store';
}

function flash_set(string $type, string $message): void
{
    $_SESSION['flash'] = ['type' => $type, 'message' => $message];
}

function flash_get(): ?array
{
    if (empty($_SESSION['flash'])) {
        return null;
    }
    $flash = $_SESSION['flash'];
    unset($_SESSION['flash']);
    return $flash;
}

function get_stores(): array
{
    $stmt = db()->query(
        "SELECT s.*, COUNT(p.id) AS product_count
         FROM stores s
         LEFT JOIN products p ON p.store_id = s.id
         GROUP BY s.id
         ORDER BY s.created_at DESC"
    );
    return $stmt->fetchAll();
}

function get_store(int $id): ?array
{
    $stmt = db()->prepare("SELECT * FROM stores WHERE id = :id LIMIT 1");
    $stmt->bindValue(':id', $id, PDO::PARAM_INT);
    $stmt->execute();
    $store = $stmt->fetch();
    return $store ?: null;
}

function get_products(?int $storeId = null, int $limit = 50): array
{
    if ($storeId) {
        $stmt = db()->prepare(
            "SELECT p.*, s.name AS store_name
             FROM products p
             JOIN stores s ON s.id = p.store_id
             WHERE p.store_id = :store_id
             ORDER BY p.created_at DESC
             LIMIT :limit"
        );
        $stmt->bindValue(':store_id', $storeId, PDO::PARAM_INT);
    } else {
        $stmt = db()->prepare(
            "SELECT p.*, s.name AS store_name
             FROM products p
             JOIN stores s ON s.id = p.store_id
             ORDER BY p.created_at DESC
             LIMIT :limit"
        );
    }
    $stmt->bindValue(':limit', $limit, PDO::PARAM_INT);
    $stmt->execute();
    return $stmt->fetchAll();
}

function get_product(int $id): ?array
{
    $stmt = db()->prepare(
        "SELECT p.*, s.name AS store_name, s.currency
         FROM products p
         JOIN stores s ON s.id = p.store_id
         WHERE p.id = :id
         LIMIT 1"
    );
    $stmt->bindValue(':id', $id, PDO::PARAM_INT);
    $stmt->execute();
    $product = $stmt->fetch();
    return $product ?: null;
}