com.torvald → net.torvald

Former-commit-id: 375604da8a20a6ba7cd0a8d05a44add02b2d04f4
Former-commit-id: 287287c5920b07618174d7a7573f049d350ded66

src/net/torvald/simplecipher/ROTUtil.kt

@@ -0,0 +1,77 @@
+package net.torvald.simplecipher
+
+/**
+ * Created by minjaesong on 16-03-20.
+ */
+object ROTUtil {
+
+    const val CODE_CAP_A = 'A'.toInt()
+    const val CODE_LOW_A = 'a'.toInt()
+
+    /**
+     * ROT encryption, default setting
+     *
+     * * Latin alph: removes diacritics and do ROT13, string reverse, capitalised.
+     * Ligatures are disassembled. Even if the target language does not have
+     * certain alphabet (e.g. C in Icelandic), such alphabet will be printed anyway.
+     *
+     * * Cyrillic: removes diacritics and do ROTnn, string reverse, capitalised.
+     *
+     * * Kana: raise Sutegana, ROT3 on vowels (a i u e o -> e o a i u), string reverse
+     * (Wa Wo -> Wo Wa), Nn will remain untouched, forced Katakana.
+     *
+     * * Hangul: ROT3 on initials\*, lower double initials to single
+     * (ㄱ ㄲ ㄴ ㄷ ㄸ ㄹ ㅁ ㅂ ㅃ ㅅ ㅆ ㅇ ㅈ ㅉ ㅊ ㅋ ㅌ ㅍ ㅎ -> ㄹ ㄹ ㅁ ㅂ ㅂ ㅅ ㅇ ㅇ ㅈ ㅈ ㅊ ㅋ ㅋ ㅌ ㅍ ㅎ ㄱ ㄴ ㄷ),
+     * string reverse
+     *
+     * * Chinese: NOT SUPPORTED
+     *
+     * * Numeric: no encrypt
+     */
+    fun encrypt(plaintext: String): String {
+
+        fun removeDiacritics(c: Char): Char {
+            val normaliseMap = hashMapOf(
+                    Pair('À', "A"),
+                    Pair('Á', "A"),
+                    Pair('Â', "A"),
+                    Pair('À', "A"),
+                    Pair('Ã', "A"),
+                    Pair('Å', "A"),
+                    Pair('Æ', "AE"),
+                    Pair('Ç', "C"),
+                    Pair('È', "E"),
+                    Pair('É', "E"),
+                    Pair('Ê', "E"),
+                    Pair('Ë', "E"),
+                    Pair('Ì', "I"),
+                    Pair('Í', "I"),
+                    Pair('Î', "I"),
+                    Pair('Ï', "I"),
+                    Pair('Ð', "D")
+            )
+            throw NotImplementedError("Feature WIP")
+        }
+
+        throw NotImplementedError("Feature WIP")
+    }
+
+    /**
+     * Note; range starts with zero
+     * @param number to rotate
+     * @param rotation
+     * @param range size of the rotation table. 4 means (0,1,2,3)
+     */
+    fun rotN(number: Int, rotation: Int, range: Int): Int {
+        return if (number < range - rotation + 1) number + rotation
+        else      number - (range - rotation + 1)
+    }
+
+    fun rot13(c: Char): Char {
+        return if (c in 'a'..'z')
+            (rotN((c.toInt() - CODE_LOW_A), 13, 26) + CODE_LOW_A).toChar()
+        else if (c in 'A'..'Z')
+            (rotN((c.toInt() - CODE_CAP_A), 13, 26) + CODE_CAP_A).toChar()
+        else c
+    }
+}