const libsodium          = require('libsodium-wrappers');
const concat_typed_array = require("concat-typed-array");
const nonce_length       = libsodium.crypto_aead_xchacha20poly1305_ietf_NPUBBYTES;

module.exports = sodium = class Sodium {
	constructor(key){
		 if(key === null) {
			 throw "Sodium: Private key not set."
		 }

		this.key = libsodium.from_hex(key);
	}

	async encrypt(plaintext){
		await libsodium.ready;

		var nonce      = libsodium.randombytes_buf(nonce_length),
		    ciphertext = libsodium.crypto_aead_xchacha20poly1305_ietf_encrypt(plaintext, null, nonce, nonce, this.key);

		console.log("nonce", nonce);
		console.log("ciphertext", ciphertext);

		return concat_typed_array(Uint8Array, nonce, ciphertext);
	}

	async decrypt(encryption){
		await libsodium.ready;

		var nonce      = encryption.slice(0, nonce_length),
		    ciphertext = encryption.slice(nonce_length);

		console.log("nonce", nonce);
		console.log("ciphertext", ciphertext);

		return libsodium.crypto_aead_xchacha20poly1305_ietf_decrypt(nonce, ciphertext, null, nonce, this.key, "text");
	}
}