export const NUMBER_LENGTH = 13
export const KEY_LENGTH = 2

export function checkNIR(nir: string, nirType: string): boolean {
	nir = nir.replace(/\s+/g, '').toUpperCase()

	const nirRegexComplex = new RegExp(
		'^'
		+ '(?<sexe>[1-4]|7|8)'
		+ '(?<anneeNaissance>\\d{2})'
		+ '(?<moisNaissance>0[1-9]|1[0-2]|2[0-9]|3[0-9]|4[0-2])'
		+ '(?<departementNaissance>\\d{2}|2A|2B|96|97\\d|98\\d|99\\d)'
		+ '(?<communeNaissance>\\d{3})'
		+ '(?<rangInscription>\\d{3})'
		+ '(?<cle>[0-9]{2})?'
		+ '$',
		'i',
	)

	const nirSimpleRegex = new RegExp(
		'^'
		+ '(?<sexe>[12])'
		+ '(?<anneeNaissance>\\d{2})'
		+ '(?<moisNaissance>0[1-9]|1[0-2]|[2-9][0-9])'
		+ '(?<departementNaissance>\\d{2}|2A|2B)'
		+ '(?<communeNaissance>\\d{3})'
		+ '(?<rangInscription>\\d{3})'
		+ '(?<cle>9[0-7]|[0-8]\\d)?'
		+ '$',
		'i',
	)
	const nirRegex = nirType === 'simple' ? nirSimpleRegex : nirRegexComplex
	return nirRegex.test(nir)
}

export function computeNIRKey(nir: string): string {
	nir = nir.replace(/\s+/g, '').toUpperCase()

	let nirNumberPart = nir.substring(0, 13)

	nirNumberPart = nirNumberPart.replace('2A', '19').replace('2B', '18')

	const nirNumber = BigInt(nirNumberPart)

	const key = 97n - (nirNumber % 97n)

	return key.toString().padStart(2, '0')
}

export function isNIRKeyValid(nir: string): boolean {
	nir = nir.replace(/\s+/g, '').toUpperCase()

	const providedKey = nir.substring(13, 15)
	const computedKey = computeNIRKey(nir)
	return providedKey === computedKey
}