import crypto from 'crypto';

export default class TpLinkCipher {
	constructor(private readonly key: Buffer, private readonly iv: Buffer) {}

	public static toBase64(data: string) {
		return Buffer.from(data.normalize('NFKC'), 'utf-8').toString('base64');
	}

	public static encodeUsername(data: string): string {
		const sha = crypto.createHash('sha1');
		sha.update(data.normalize('NFKC'));
		return sha.digest('hex');
	}

	public static createKeyPair(): Promise<{
		public: string;
		private: string;
	}> {
		return new Promise((resolve, reject) => {
			crypto.generateKeyPair(
				'rsa',
				{
					modulusLength: 1024,
				},
				(err, publicK, privateK) => {
					if (err) {
						return reject(err);
					}

					const pub = publicK
						.export({
							format: 'pem',
							type: 'spki',
						})
						.toString('base64');
					const priv = privateK
						.export({
							format: 'pem',
							type: 'pkcs1',
						})
						.toString('base64');

					resolve({
						public: pub,
						private: priv,
					});
				},
			);
		});
	}

	public encrypt(data: string) {
		const cipher = crypto.createCipheriv('aes-128-cbc', this.key, this.iv);
		const encrypted = cipher.update(data, 'utf8', 'base64');
		return `${encrypted}${cipher.final('base64')}`;
	}

	public decrypt(data: string) {
		const decipher = crypto.createDecipheriv('aes-128-cbc', this.key, this.iv);
		const decrypted = decipher.update(data, 'base64', 'utf8');
		return `${decrypted}${decipher.final('utf8')}`;
	}
}