From ab989d189a8ed1b515155fb92e6fcc237131b99f Mon Sep 17 00:00:00 2001
From: NaiJi <naijiworld@protonmail.com>
Date: Tue, 22 Mar 2022 14:58:12 +0300
Subject: [PATCH] Fix encoding

---
 code.c.ino     |  70 +++++++++++++++++++++++---
 enigma_types.h | 131 ++++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 186 insertions(+), 15 deletions(-)

diff --git a/code.c.ino b/code.c.ino
index f9d3542..3c576c7 100644
--- a/code.c.ino
+++ b/code.c.ino
@@ -18,9 +18,9 @@ HCuOLED HCuOLED(SH1106, CS_DI, DC_DI, RST_DI);
 LiquidCrystal_I2C lcd(0x27, 16, 2);
 String lcd_output;
 
-size_t toKeyIndex(const String& input_hex)
+uint16_t toKeyIndex(const String& input_hex)
 {
-    size_t index = -1;
+    uint16_t index = -1;
     for (size_t i = 0; i < ALPHABET_SIZE; ++i)
     {
         if (key_values[i].hex == input_hex)
@@ -33,14 +33,67 @@ size_t toKeyIndex(const String& input_hex)
     return index;
 }
 
+size_t forward(size_t index, size_t current_wheel)
+{
+    size_t input = (index + key_shifts[current_wheel]) % ALPHABET_SIZE;
+
+    size_t output = 0;
+    for (size_t i = 0; i < ALPHABET_SIZE; ++i)
+    {
+        if (mutations[current_wheel][i].from == input)
+        {
+            output = mutations[current_wheel][i].to;
+            break;
+        }
+    }
+
+    return output;
+}
+
+size_t backward(size_t index, size_t current_wheel)
+{
+    int output = 0;
+
+    for (size_t i = 0; i < ALPHABET_SIZE; ++i)
+    {
+        if (input == mutations[current_wheel][i].to)
+        {
+            output = (mutations[current_wheel][i].from - key_shifts[current_wheel]);
+            while (output < 0)
+            {
+                output += ALPHABET_SIZE;
+            }
+
+            output = output % ALPHABET_SIZE;
+        }
+    }
+
+    return output;
+}
+
 size_t encode(size_t index)
 {
     for (size_t i = 0; i < WHEELS_AMOUNT; ++i)
     {
-        index += key_shifts[i];
+        index = forward(index, i);
     }
 
-    return index % ALPHABET_SIZE;
+    size_t overturning_input = index % ALPHABET_SIZE;
+    for (size_t i = 0; i < ALPHABET_SIZE; ++i)
+    {
+        if (mutations[3][i].from == overturning_input)
+        {
+            index = mutations[3][i].to;
+            break;
+        }
+    }
+
+    for (size_t i = (WHEELS_AMOUNT - 1); i >= 0; --i)
+    {
+        index = backward(index, i);
+    }
+
+    return index;
 }
 
 void rotate()
@@ -75,17 +128,17 @@ void loop()
         return;
 
     const String value = String(key, HEX);
-    const size_t index = toKeyIndex(value);
+    const uint16_t index = toKeyIndex(value);
     if (index == -1)
         return;
 
-    rotate();
+    size_t encoded_index = encode(index);
+    const String encoded_letter = key_values[encoded_index].view;
 
-    const String encoded_letter = key_values[encode(index)].view;
     size_t y = 0;
     for (size_t i = 0; i < WHEELS_AMOUNT; ++i)
     {
-        HCuOLED.Cursor(4,y);
+        HCuOLED.Cursor(4, y);
         HCuOLED.SetFont(MedProp_11pt);
         HCuOLED.Print(key_shifts[i]);
         y += 20;
@@ -101,4 +154,5 @@ void loop()
 
     lcd.clear();
     lcd.print(lcd_output);
+    rotate();
 }
diff --git a/enigma_types.h b/enigma_types.h
index 3306cbb..64bb1c7 100644
--- a/enigma_types.h
+++ b/enigma_types.h
@@ -38,16 +38,133 @@ const Key key_values[ALPHABET_SIZE] =
     {"4d", "m"}  // Code4D - m
 };
 
-// Сдвиг в алфавите для каждого из "дисков".
-// Обязан быть в отрезке [1; 25], так как полный круг
-// возвращает значение обратно в 0.
-// Таким образом, при конфигурации { 1, 2, 5 } и
-// нажатой ' d ' сначала произойдёт сдвиг на 1, ' d '
-// станет ' f ', потом на 2, ' f ' станет ' h ', 
-// в конце ещё сдвиг на 5 и ' h ' станет ' x '.
+// Сдвиг в алфавите для каждого из "дисков"
+// относительно их нормального состояния
 size_t key_shifts[WHEELS_AMOUNT] =
 {
     3,
     1,
     2
+};
+
+struct Mutation
+{
+    size_t from = 0;
+    size_t to = 0;
+};
+
+const Mutation mutations[WHEELS_AMOUNT + 1][ALPHABET_SIZE] =
+{
+    {
+        {0, 15 },
+        {1, 4 },
+        {2, 25 },
+        {3, 20 },
+        {4, 14 },
+        {5, 7 },
+        {6, 23 },
+        {7, 18 },
+        {8, 2 },
+        {9, 21 },
+        {10, 5 },
+        {11, 12 },
+        {12, 19 },
+        {13, 1 },
+        {14, 6 },
+        {15, 11 },
+        {16, 17 },
+        {17, 8 },
+        {18, 13 },
+        {19, 16 },
+        {20, 9 },
+        {21, 22 },
+        {22, 0 },
+        {23, 24 },
+        {24, 3 },
+        {25, 10 }
+    },
+    {
+        {0, 25 },
+        {1, 14 },
+        {2, 20 },
+        {3, 4 },
+        {4, 18 },
+        {5, 24 },
+        {6, 3 },
+        {7, 10 },
+        {8, 5 },
+        {9, 22 },
+        {10, 15 },
+        {11, 2 },
+        {12, 8 },
+        {13, 16 },
+        {14, 23 },
+        {15, 7 },
+        {16, 12 },
+        {17, 21 },
+        {18, 1 },
+        {19, 11 },
+        {20, 6 },
+        {21, 13 },
+        {22, 9 },
+        {23, 17 },
+        {24, 0 },
+        {25, 19 }
+    },
+    {
+        {0, 4 },
+        {1, 7 },
+        {2, 17 },
+        {3, 21 },
+        {4, 23 },
+        {5, 6 },
+        {6, 0 },
+        {7, 14 },
+        {8, 1 },
+        {9, 16 },
+        {10, 20 },
+        {11, 18 },
+        {12, 8 },
+        {13, 12 },
+        {14, 25 },
+        {15, 5 },
+        {16, 11 },
+        {17, 24 },
+        {18, 13 },
+        {19, 22 },
+        {20, 10 },
+        {21, 19 },
+        {22, 15 },
+        {23, 3 },
+        {24, 9 },
+        {25, 2 }
+    },
+    {
+        {0, 21},
+        {1, 10},
+        {2, 22},
+        {3, 17},
+        {4, 6},
+        {5, 8},
+        {6, 4},
+        {7, 19},
+        {8, 5}, 
+        {9, 25},
+        {10, 1}, 
+        {11, 20}, 
+        {12, 18}, 
+        {13, 15}, 
+        {14, 16}, 
+        {15, 13}, 
+        {16, 14}, 
+        {17, 3}, 
+        {18, 12}, 
+        {19, 7},
+        {20, 11},
+        {21, 0},
+        {22, 2},
+        {23, 24}, 
+        {24, 23},
+        {25, 9}
+    }
 };
\ No newline at end of file