export function normalizeAvatarUrl(value: unknown): string {
	if (typeof value !== "string") return "";
	const url = value.trim();
	if (!url) return "";
	let parsed: URL;
	try {
		parsed = new URL(url);
	} catch {
		throw new Error(`无效头像链接: ${url}`);
	}
	if (parsed.protocol !== "http:" && parsed.protocol !== "https:") {
		throw new Error("头像链接仅支持 http 或 https");
	}
	return parsed.toString();
}

export function normalizeConfigKey(key: unknown): string {
	if (typeof key !== "string") throw new Error("配置键必须是字符串");
	const trimmed = key.trim();
	if (!trimmed) throw new Error("配置键不能为空");
	if (trimmed.length > 128) throw new Error("配置键过长");
	if (!/^[a-zA-Z][a-zA-Z0-9_.-]*$/.test(trimmed)) {
		throw new Error("配置键格式无效");
	}
	return trimmed;
}

export function normalizeConfigValue(value: unknown): string {
	if (typeof value !== "string") throw new Error("配置值必须是字符串");
	if (value.length > 65536) throw new Error("配置值过长");
	return value;
}