feat: algoritma porta cipher (#391)

* add: swapCharFromPeriodicTable function

* add: getCurrentColumnRow function

* add: getColumn function

* add: filterToAlphabetOnly function

* add: filterToAlphabetOnly for string and keys input

* add: groupOfString by the length of keys

* add: change groupOfStrings to groupOfString

* add: loop groupOfString and swap each Char based on key char

* add: test encrypt and decrypt string with portaCipher

* docs: filterToAlphabetOnly function

* docs: getCurrentColumnRow function

* docs: swapCharFromPeriodicTable function

* docs: portaCipher function

* docs: portaCipher function returns value explanation

* docs: change to Indonesia

* feat: change literal string to double quotes

* feat: change groupOfString RegExp method to looping

* docs: add porta cipher algorithm reference link

Author: DikDns

algorithm/cipher/porta.js

@@ -0,0 +1,108 @@
+/**
+ * @summary Implementasi Porta Cipher
+ * @param {string} string
+ * @param {string} keys
+ * @description Porta Cipher adalah jenis cipher substitusi polialfabet yang ditemukan oleh Giovanni Battista della Porta. Porta chiper menggunakan 13 huruf alphabet (A-M) dan (N-Z) yang bersifat timbal balik.
+ * @link Penjelasan lebih lanjut: http://practicalcryptography.com/ciphers/porta-cipher/
+ * @link Implementasi berdasarkan: http://www.cryptogram.org/downloads/aca.info/ciphers/Porta.pdf
+ * @returns string yang telah terenkripsi atau terdekripsi
+ * @example portaCipher("hello world")
+ * //=> "OYTUBCHJUQ"
+ */
+
+function portaCipher(string, keys = "PORTA") {
+  /**
+   * @summary mengambil kolom berdasarkan index genap
+   * @description contoh arrray [[A,B], [C,D], [E,F], ...]
+   *  - [A,B] index 0
+   *  - [C,D] index 2
+   *  - [E,F] index 4
+   * @param {string} key
+   * @returns
+   */
+  function getColumn(key) {
+    const charACode = 65;
+    let temp = key.charCodeAt() - charACode;
+
+    return temp % 2 !== 0 ? --temp : temp;
+  }
+
+  /**
+   * @summary mengambil baris dari nomor kolom berdasarkan key
+   * @param {string} key
+   * @returns
+   */
+  function getCurrentColumnRow(key) {
+    const nToZ = "NOPQRSTUVWXYZ";
+    const column = getColumn(key);
+    const shiftLength = column / 2;
+    const endOfShiftLength = nToZ.length + shiftLength;
+
+    return (
+      nToZ.substring(shiftLength, endOfShiftLength) +
+      nToZ.substring(0, shiftLength)
+    );
+  }
+
+  /**
+   * @summary menukar huruf berdasarkan key di tabel
+   * @param {string} key
+   * @param {string} charToSwap
+   * @returns
+   */
+  function swapCharFromPeriodicTable(key, charToSwap) {
+    const aToMColumn = "ABCDEFGHIJKLM";
+    const keyColumn = getCurrentColumnRow(key);
+
+    return aToMColumn.includes(charToSwap)
+      ? keyColumn[aToMColumn.indexOf(charToSwap)]
+      : aToMColumn[keyColumn.indexOf(charToSwap)];
+  }
+
+  /**
+   * @summary mengubah string menjadi alfabet saja
+   * @description {ABCDEFGHIJKLMNOPQRSTUVWXYZ}
+   * @param {string} key
+   * @param {string} charToSwap
+   * @returns
+   */
+  function filterToAlphabetOnly(string) {
+    return string
+      .toUpperCase()
+      .split(/[\W\d]/)
+      .join("");
+  }
+
+  const filteredString = filterToAlphabetOnly(string);
+  const filteredKeys = filterToAlphabetOnly(keys);
+
+  const groupOfString = [];
+
+  for (let i = 0; i < filteredString.length; i += filteredKeys.length) {
+    groupOfString.push(filteredString.substring(i, i + filteredKeys.length));
+  }
+
+  let result = "";
+
+  for (let i = 0; i < groupOfString.length; i++) {
+    const currentString = groupOfString[i];
+
+    for (let j = 0; j < currentString.length; j++) {
+      result += swapCharFromPeriodicTable(filteredKeys[j], currentString[j]);
+    }
+  }
+
+  return result;
+}
+
+console.log(portaCipher("Andika Eka Kurnia"));
+// UGYRXUYSWXAKFRN
+
+console.log(portaCipher("UGYRXUYSWXAKFRN"));
+// ANDIKAEKAKURNIA
+
+console.log(portaCipher("Andika Eka Kurnia", "DikDns"));
+// OJVWQWSOSYBIMZS
+
+console.log(portaCipher("OJVWQWSOSYBIMZS", "DikDns"));
+// ANDIKAEKAKURNIA