/* global expect */

function getRandomValues(arr) {
	for (let i = 0; i < arr.length; i++) {
		arr[i] = Math.floor(Math.random()*256);
	}
}

window = {
	crypto: {
		getRandomValues: getRandomValues
	}
};

describe("Chacha", function() {
	let cryptoJS = require("../../dist/main.js");
	let util = cryptoJS.util;
	let Chacha20 = cryptoJS.Chacha20;
	let encrypt = cryptoJS.encrypt;
	let decrypt = cryptoJS.decrypt;
	let str2utf8 = util.str2utf8;

	let key = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31];
	let nonce1 = [0, 0, 0, 9, 0, 0, 0, 74, 0, 0, 0, 0];
	let nonce2 = [0, 0, 0, 0, 0, 0, 0, 74, 0, 0, 0, 0];
	let plaintext = "Ladies and Gentlemen of the class of '99: If I could offer you only one tip for the future, sunscreen would be it.";

	describe("Chacha20", function() {
		it("should return a correct test vector", function() {
			let cipher = new Chacha20(key, nonce1);
			let output = cipher._computeBlock().map(x => x >>> 0);
			let expected = [0xe4e7f110, 0x15593bd1, 0x1fdd0f50, 0xc47120a3, 0xc7f4d1c7, 0x0368c033, 0x9aaa2204, 0x4e6cd4c3, 0x466482d2, 0x09aa9f07, 0x05d7c214, 0xa2028bd9, 0xd19c12b5, 0xb94e16de, 0xe883d0cb, 0x4e3c50a2];
			expect(output).toEqual(expected);
		});

		it("should output a correct key stream", function() {
			let cipher = new Chacha20(key, nonce2);
			let expected = [34, 79, 81, 243, 64, 27, 217, 225, 47, 222, 39, 111, 184, 99, 29, 237, 140, 19, 31, 130, 61, 44, 6, 226, 126, 79, 202, 236, 158, 243, 207, 120, 138, 59, 10, 163, 114, 96, 10, 146, 181, 121, 116, 205, 237, 43, 147, 52, 121, 76, 186, 64, 198, 62, 52, 205, 234, 33, 44, 76, 240, 125, 65, 183, 105, 166, 116, 159, 63, 99, 15, 65, 34, 202, 254, 40, 236, 77, 196, 126, 38, 212, 52, 109, 112, 185, 140, 115, 243, 233, 197, 58, 196, 12, 89, 69, 57, 139, 110, 218, 26, 131, 44, 137, 193, 103, 234, 205, 144, 29, 126, 43, 243, 99];
			expected.forEach(b => {
				expect(cipher.getByte()).toEqual(b);
			});
		});

	});

	describe("encrypt", function() {
		it("should correctly encrypt an example text", function() {
			let ciphertext = [110, 46, 53, 154, 37, 104, 249, 128, 65, 186, 7, 40, 221, 13, 105, 129, 233, 126, 122, 236, 29, 67, 96, 194, 10, 39, 175, 204, 253, 159, 174, 11, 249, 27, 101, 197, 82, 71, 51, 171, 143, 89, 61, 171, 205, 98, 179, 87, 22, 57, 214, 36, 230, 81, 82, 171, 143, 83, 12, 53, 159, 8, 97, 216, 7, 202, 13, 191, 80, 13, 106, 97, 86, 163, 142, 8, 138, 34, 182, 94, 82, 188, 81, 77, 22, 204, 248, 6, 129, 140, 233, 26, 183, 121, 55, 54, 90, 249, 11, 191, 116, 163, 91, 230, 180, 11, 142, 237, 242, 120, 94, 66, 135, 77];
			expect(encrypt(str2utf8(plaintext), key, nonce2)).toEqual([nonce2, ciphertext]);
		});
	});

	describe("decrypt", function() {
		it("should be able to decrypt a Chacha20 encrypted text", function() {
			let text = str2utf8(plaintext);
			let key = [];
			for (let i = 0; i < 16; i++) {key.push(Math.floor(Math.random() * 256));}
			let [nonce, ciphertext] = encrypt(text, key);
			expect(decrypt(ciphertext, key, nonce)).toEqual(text);
		});
	});

});