From bcb347a8d967eebca41cf526334f1099d7db47b8 Mon Sep 17 00:00:00 2001
From: KKlochko <KKlochko@protonmail.com>
Date: Sat, 28 Oct 2023 17:16:04 +0300
Subject: [PATCH] Add a function to encrypt a message with the gamma cipher.

---
 src/cipher_analytical_machine/ciphers/gamma.clj  | 16 +++++++++++++++-
 .../ciphers/gamma_test.clj                       |  7 +++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/cipher_analytical_machine/ciphers/gamma.clj b/src/cipher_analytical_machine/ciphers/gamma.clj
index c6c0e76..1e5c422 100644
--- a/src/cipher_analytical_machine/ciphers/gamma.clj
+++ b/src/cipher_analytical_machine/ciphers/gamma.clj
@@ -1,5 +1,8 @@
 (ns cipher-analytical-machine.ciphers.gamma
-  (:require [clojure.string :as cs])
+  (:require
+   [clojure.set :as set]
+   [clojure.string :as cs]
+   [cipher-analytical-machine.ciphers.simple-substitution :as ss])
   (:gen-class))
 
 (defn add-mod
@@ -40,6 +43,17 @@
          (map vector array)
          (map (fn [[a g]] (add-mod a g module))))))
 
+(defn encrypt-message
+  "Encrypt a message using the gamma cipher. The function is case-insensitive. The key is an array of three elements [a b c]. The array contains integer in range [0, module)."
+  [key symbols message]
+  (let [module (count symbols)
+        table (ss/generate-sorted-substitution-table symbols)]
+    (->> message
+         (ss/decrypt-by-table (set/map-invert table))
+         (encrypt-array key module)
+         (ss/decrypt-by-table table)
+         (cs/join))))
+
 (defn decrypt-array
   "Decrypt an array using the gamma cipher. The function is case-insensitive. The key is an array of three elements [a b c]. The array contains integer in range [0, module)."
   [key module array]
diff --git a/test/cipher_analytical_machine/ciphers/gamma_test.clj b/test/cipher_analytical_machine/ciphers/gamma_test.clj
index f12757c..e9975bc 100644
--- a/test/cipher_analytical_machine/ciphers/gamma_test.clj
+++ b/test/cipher_analytical_machine/ciphers/gamma_test.clj
@@ -39,6 +39,13 @@
       [4 32 15] 33 [3 14 1 4 18 19 23 8 27 17] [6 28 2 8 3 5 13 16 21 1]
       [1 2  3 ] 3  [0 2 1 1 0 1 2 2 0]         [0 1 2 2 0 2 1 1 0])))
 
+(deftest encrypt-message-test
+  (testing "Checking that the message is encrypted as expected"
+    (are [key symbols message expected]
+        (= expected (encrypt-message key symbols message))
+      [4 32 15] "абвгґдеєжзиіїйклмнопрстуфхцчшщьюя" "гкбґопужчн" "ешвжгдймсб"
+      [1 2  3 ] "абв"  "авббабвва"  "абввавбба")))
+
 (deftest decrypt-array-test
   (testing "Checking that the message is decrypted as expected."
     (are [key module array expected]