const WHITESPACE = /\s+/

function firstCharacters(value: string, count: number) {
	return Array.from(value).slice(0, count).join('')
}

export function accountName(username: string, displayName?: string | null) {
	return displayName ? displayName : username
}

export function accountInitials(username: string, displayName?: string | null) {
	const words = (displayName ?? '').trim().split(WHITESPACE).filter(Boolean)
	if (words.length >= 2) {
		return words
			.slice(0, 2)
			.map((word) => firstCharacters(word, 1))
			.join('')
			.toUpperCase()
	}
	const source = words[0] ?? username
	return firstCharacters(source, 2).toUpperCase()
}