<?php
declare(strict_types=1);

function ensureWorldsTable(): void {
    $sql = "CREATE TABLE IF NOT EXISTS worlds (
        id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
        name VARCHAR(120) NOT NULL,
        size INT UNSIGNED NOT NULL DEFAULT 16,
        world_json MEDIUMTEXT NOT NULL,
        created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
        updated_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
        INDEX idx_worlds_updated_at (updated_at)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4";
    db()->exec($sql);
}

function listWorlds(int $limit = 10): array {
    $stmt = db()->prepare('SELECT id, name, size, updated_at FROM worlds ORDER BY updated_at DESC LIMIT :limit');
    $stmt->bindValue(':limit', $limit, PDO::PARAM_INT);
    $stmt->execute();
    return $stmt->fetchAll();
}

function getWorldById(int $id): ?array {
    $stmt = db()->prepare('SELECT id, name, size, world_json, created_at, updated_at FROM worlds WHERE id = :id');
    $stmt->bindValue(':id', $id, PDO::PARAM_INT);
    $stmt->execute();
    $row = $stmt->fetch();
    return $row ?: null;
}

function saveWorld(string $name, string $worldJson, int $size): int {
    $stmt = db()->prepare('INSERT INTO worlds (name, size, world_json) VALUES (:name, :size, :world_json)');
    $stmt->bindValue(':name', $name);
    $stmt->bindValue(':size', $size, PDO::PARAM_INT);
    $stmt->bindValue(':world_json', $worldJson);
    $stmt->execute();
    return (int)db()->lastInsertId();
}