function normalizeTimestamp(ts) {
	let value = parseInt(ts, 10)
	if (!value) value = Date.now()
	if (String(value).length === 10) value *= 1000
	return value
}

function padUnit(value, width) {
	const text = String(value)
	return width > 1 ? text.padStart(width, '0') : text
}

export function formatTimestamp(ts, pattern = 'yyyy-mm-dd') {
	const date = new Date(normalizeTimestamp(ts))
	const tokens = {
		'y+': String(date.getFullYear()),
		'm+': String(date.getMonth() + 1),
		'd+': String(date.getDate()),
		'h+': String(date.getHours()),
		'M+': String(date.getMinutes()),
		's+': String(date.getSeconds())
	}
	let output = pattern
	for (const token of Object.keys(tokens)) {
		const match = new RegExp(`(${token})`).exec(output)
		if (!match) continue
		const width = match[1].length
		output = output.replace(match[1], padUnit(tokens[token], width))
	}
	return output
}

export function createRelativeTimeFormatter(i18n) {
	const translate = (key, fallback) => {
		try {
			return i18n ? i18n.t(key) : fallback
		} catch (_) {
			return fallback
		}
	}
	return { translate }
}

export function socialRelativeTime(ts, pattern = 'yyyy-mm-dd', i18n) {
	const { translate } = createRelativeTimeFormatter(i18n)
	const seconds = Math.floor((Date.now() - normalizeTimestamp(ts)) / 1000)
	if (seconds < 300) return translate('find.just-now', '刚刚')
	if (seconds < 3600) return `${Math.floor(seconds / 60)}${translate('find.minutes-ago', '分钟前')}`
	if (seconds < 86400) return `${Math.floor(seconds / 3600)}${translate('find.hours-ago', '小时前')}`
	if (seconds < 2592000) return `${Math.floor(seconds / 86400)}${translate('find.days-ago', '天前')}`
	if (pattern === false) {
		if (seconds < 365 * 86400) {
			return `${Math.floor(seconds / (86400 * 30))}${translate('find.months-ago', '个月前')}`
		}
		return `${Math.floor(seconds / (86400 * 365))}${translate('find.years-ago', '年前')}`
	}
	return formatTimestamp(ts, pattern)
}

export function chatBubbleTime(ts, i18n) {
	const { translate } = createRelativeTimeFormatter(i18n)
	const seconds = Math.floor((Date.now() - normalizeTimestamp(ts)) / 1000)
	if (seconds < 86400) return formatTimestamp(ts, 'hh:MM')

	const weekdays = (() => {
		try {
			const list = i18n.t('find.weekdays', { returnObjects: true })
			if (Array.isArray(list)) return list
		} catch (_) {}
		return ['日', '一', '二', '三', '四', '五', '六']
	})()

	const locale = i18n ? i18n.locale : 'zh-Hans'
	const chineseStyle = locale.startsWith('zh') || locale === 'ja'
	const clock = formatTimestamp(ts, 'hh:MM')
	const when = new Date(normalizeTimestamp(ts))
	const dayGap = new Date().getDate() - when.getDate()

	if (seconds < 86400 * 7) {
		if (dayGap === 1) return `${translate('find.yesterday', '昨天')} ${clock}`
		if (dayGap === 2) return `${translate('find.dayBeforeYesterday', '前天')} ${clock}`
		const weekLabel = weekdays[when.getDay()]
		return chineseStyle
			? `${translate('find.week', '星期')}${weekLabel} ${clock}`
			: `${weekLabel} ${clock}`
	}
	if (seconds >= 86400 * 7) return formatTimestamp(ts, 'mm-dd hh:MM')
	return formatTimestamp(ts, 'yyyy-mm-dd hh:MM')
}