export class RandomGenerator {
	/**
	 *  discuss at: http://locutus.io/php/sha1/
	 * original by: Webtoolkit.info (http://www.webtoolkit.info/)
	 * improved by: Michael White (http://getsprink.com)
	 * improved by: Kevin van Zonneveld (http://kvz.io)
	 *    input by: Brett Zamir (http://brett-zamir.me)
	 *      note 1: Keep in mind that in accordance with PHP, the whole string is buffered and then
	 *      note 1: hashed. If available, we'd recommend using Node's native crypto modules directly
	 *      note 1: in a steaming fashion for faster and more efficient hashing
	 *   example 1: sha1('Kevin van Zonneveld')
	 *   returns 1: '54916d2e62f65b3afa6e192e6a601cdbe5cb5897'
	 */
	static sha1(str: string) {
		let _rotLeft = function (n: any, s: any) {
			let t4 = (n << s) | (n >>> (32 - s));
			return t4;
		};

		let _cvtHex = function (val: any) {
			let str = '';
			let i;
			let v;

			for (i = 7; i >= 0; i--) {
				v = (val >>> (i * 4)) & 0x0f;
				str += v.toString(16);
			}
			return str;
		};

		let blockstart;
		let i, j;
		let W = new Array(80);
		let H0 = 0x67452301;
		let H1 = 0xefcdab89;
		let H2 = 0x98badcfe;
		let H3 = 0x10325476;
		let H4 = 0xc3d2e1f0;
		let A, B, C, D, E;
		let temp;

		// utf8_encode
		str = /*unescape*/ encodeURIComponent(str);
		let strLen = str.length;

		let wordArray = [];
		for (i = 0; i < strLen - 3; i += 4) {
			j =
				(str.charCodeAt(i) << 24) |
				(str.charCodeAt(i + 1) << 16) |
				(str.charCodeAt(i + 2) << 8) |
				str.charCodeAt(i + 3);
			wordArray.push(j);
		}

		switch (strLen % 4) {
			case 0:
				i = 0x080000000;
				break;
			case 1:
				i = (str.charCodeAt(strLen - 1) << 24) | 0x0800000;
				break;
			case 2:
				i = (str.charCodeAt(strLen - 2) << 24) | (str.charCodeAt(strLen - 1) << 16) | 0x08000;
				break;
			case 3:
				i =
					(str.charCodeAt(strLen - 3) << 24) |
					(str.charCodeAt(strLen - 2) << 16) |
					(str.charCodeAt(strLen - 1) << 8) |
					0x80;
				break;
		}

		wordArray.push(i);

		while (wordArray.length % 16 !== 14) {
			wordArray.push(0);
		}

		wordArray.push(strLen >>> 29);
		wordArray.push((strLen << 3) & 0x0ffffffff);

		for (blockstart = 0; blockstart < wordArray.length; blockstart += 16) {
			for (i = 0; i < 16; i++) {
				W[i] = wordArray[blockstart + i];
			}
			for (i = 16; i <= 79; i++) {
				W[i] = _rotLeft(W[i - 3] ^ W[i - 8] ^ W[i - 14] ^ W[i - 16], 1);
			}

			A = H0;
			B = H1;
			C = H2;
			D = H3;
			E = H4;

			for (i = 0; i <= 19; i++) {
				temp = (_rotLeft(A, 5) + ((B & C) | (~B & D)) + E + W[i] + 0x5a827999) & 0x0ffffffff;
				E = D;
				D = C;
				C = _rotLeft(B, 30);
				B = A;
				A = temp;
			}

			for (i = 20; i <= 39; i++) {
				temp = (_rotLeft(A, 5) + (B ^ C ^ D) + E + W[i] + 0x6ed9eba1) & 0x0ffffffff;
				E = D;
				D = C;
				C = _rotLeft(B, 30);
				B = A;
				A = temp;
			}

			for (i = 40; i <= 59; i++) {
				temp =
					(_rotLeft(A, 5) + ((B & C) | (B & D) | (C & D)) + E + W[i] + 0x8f1bbcdc) & 0x0ffffffff;
				E = D;
				D = C;
				C = _rotLeft(B, 30);
				B = A;
				A = temp;
			}

			for (i = 60; i <= 79; i++) {
				temp = (_rotLeft(A, 5) + (B ^ C ^ D) + E + W[i] + 0xca62c1d6) & 0x0ffffffff;
				E = D;
				D = C;
				C = _rotLeft(B, 30);
				B = A;
				A = temp;
			}

			H0 = (H0 + A) & 0x0ffffffff;
			H1 = (H1 + B) & 0x0ffffffff;
			H2 = (H2 + C) & 0x0ffffffff;
			H3 = (H3 + D) & 0x0ffffffff;
			H4 = (H4 + E) & 0x0ffffffff;
		}

		temp = _cvtHex(H0) + _cvtHex(H1) + _cvtHex(H2) + _cvtHex(H3) + _cvtHex(H4);
		return temp.toLowerCase();
	}
}