import { clsx, type ClassValue } from "clsx";
import { twMerge } from "tailwind-merge";

/** 合并 className：clsx 处理条件类，tailwind-merge 消解冲突的 Tailwind 类 */
export function cn(...inputs: ClassValue[]): string {
	return twMerge(clsx(inputs));
}

/** 将日期格式化为中文可读形式，如 2025 年 3 月 8 日 */
export function formatDate(date: string, locale = "zh-CN"): string {
	return new Intl.DateTimeFormat(locale, {
		year: "numeric",
		month: "long",
		day: "numeric",
		timeZone: "UTC",
	}).format(new Date(`${date}T00:00:00Z`));
}

/** 机器可读日期，用于 <time dateTime> */
export function toDateTimeAttribute(date: string): string {
	return new Date(`${date}T00:00:00Z`).toISOString();
}

/** 拼接绝对 URL，用于 canonical / OG / sitemap */
export function absoluteUrl(base: string, pathname: string): string {
	const base$ = base.replace(/\/+$/, "");
	const path$ = pathname.startsWith("/") ? pathname : `/${pathname}`;
	return `${base$}${path$}`;
}