From f340697245d1c41b5e3b6c5341406fc4881683bb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebasti=C3=A1n=20Ba=C4=8D=C3=ADk?=
 <sebastianlipkos@gmail.com>
Date: Tue, 7 Nov 2023 22:15:09 +0100
Subject: [PATCH] methods fixed + tests written

---
 src/modules/commerce/Commerce.cpp     | 59 +++++++++++++++----
 src/modules/commerce/CommerceTest.cpp | 82 +++++++++++++++++++++++++++
 2 files changed, 129 insertions(+), 12 deletions(-)

diff --git a/src/modules/commerce/Commerce.cpp b/src/modules/commerce/Commerce.cpp
index 340881e8c..f83385b5d 100644
--- a/src/modules/commerce/Commerce.cpp
+++ b/src/modules/commerce/Commerce.cpp
@@ -43,64 +43,99 @@ std::string Commerce::productFullName()
     return fmt::format("{} {} {}", productAdjective(), productMaterial(), productName());
 }
 
-std::string EAN13()
+std::string Commerce::EAN13()
 {
     std::string ean13 = String::numeric(12, false);
 
     int sum = 0;
     for (size_t i = 0; i < 12; i++)
     {
-        sum += (i % 2 == 0) ? (ean13[i] - '0') : 3 * (ean13[i] - '0');
+        if (i % 2 == 0) {
+            sum += (ean13[i] - '0');
+        }
+        else {
+            sum += 3 * (ean13[i] - '0');
+        }
     }
     
-    int checkDigit = 10 - (sum % 10);
+    int checkDigit = sum % 10;
+
+    if (checkDigit != 0) {
+        checkDigit = 10 - checkDigit;
+    }
 
     return ean13 + std::to_string(checkDigit);
 }
 
-std::string EAN8()
+std::string Commerce::EAN8()
 {
     std::string ean8 = String::numeric(7, false);
 
     int sum = 0;
     for (size_t i = 0; i < 7; i++)
     {
-        sum += (i % 2 == 0) ? (ean8[i] - '0') : 3 * (ean8[i] - '0');
+        if (i % 2 == 0) {
+            sum += 3 * (ean8[i] - '0');
+        }
+        else {
+            sum += (ean8[i] - '0');
+        }
     }
     
-    int checkDigit = 10 - (sum % 10);
+    int checkDigit = sum % 10;
+
+    if (checkDigit != 0) {
+        checkDigit = 10 - checkDigit;
+    }
 
     return ean8 + std::to_string(checkDigit);
 }
 
-std::string ISBN13()
+std::string Commerce::ISBN13()
 {
     std::string isbn13 = String::numeric(12, true);
 
     int sum = 0;
     for (size_t i = 0; i < 12; i++)
     {
-        sum += (i % 2 == 0) ? (isbn13[i] - '0') : 3 * (isbn13[i] - '0');
+        if (i % 2 == 0) {
+            sum += (isbn13[i] - '0');
+        }
+        else {
+            sum += 3 * (isbn13[i] - '0');
+        }
     }
     
-    int checkDigit = 10 - (sum % 10);
+    int checkDigit = sum % 10;
+
+    if (checkDigit != 0) {
+        checkDigit = 10 - checkDigit;
+    }
 
     return isbn13 + std::to_string(checkDigit);
 }
 
-std::string ISBN10()
+std::string Commerce::ISBN10()
 {
     std::string isbn10 = String::numeric(9, true);
 
     int sum = 0, weight = 10;
     for (size_t i = 0; i < 9; i++)
     {
-        sum += isbn10[i] * weight;
+        sum += (isbn10[i] - '0') * weight;
         weight--;
     }
     
-    int checkDigit = 10 - (sum % 10);
+    int checkDigit = sum % 11;
+
+    if (checkDigit != 0) {
+        checkDigit = 11 - checkDigit;
+    }
 
+    if (checkDigit == 10) {
+        return isbn10 + "X";
+    }
+    
     return isbn10 + std::to_string(checkDigit);
 }
 }
diff --git a/src/modules/commerce/CommerceTest.cpp b/src/modules/commerce/CommerceTest.cpp
index ed49b5248..7fb206efd 100644
--- a/src/modules/commerce/CommerceTest.cpp
+++ b/src/modules/commerce/CommerceTest.cpp
@@ -111,3 +111,85 @@ TEST_F(CommerceTest, shouldGenerateProductName)
     ASSERT_TRUE(std::ranges::any_of(productNames, [generatedProductName](const std::string& productName)
                                     { return productName == generatedProductName; }));
 }
+
+TEST_F(CommerceTest, shouldGenerateEan13)
+{
+    const auto generatedEan13 = Commerce::EAN13();
+    
+    int sum = 0;
+    for (size_t i = 0; i < 13; i++)
+    {
+        if (i % 2 == 0) {
+            sum += (generatedEan13[i] - '0');
+        }
+        else {
+            sum += 3 * (generatedEan13[i] - '0');
+        }
+    }
+
+    ASSERT_EQ(generatedEan13.size(), 13);
+    ASSERT_TRUE(sum % 10 == 0);
+}
+
+TEST_F(CommerceTest, shouldGenerateEan8)
+{
+    const auto generatedEan8 = Commerce::EAN8();
+    
+    int sum = 0;
+    for (size_t i = 0; i < 8; i++)
+    {
+        if (i % 2 == 0) {
+            sum += 3 * (generatedEan8[i] - '0');
+        }
+        else {
+            sum += (generatedEan8[i] - '0');
+        }
+    }
+
+    ASSERT_EQ(generatedEan8.size(), 8);
+    ASSERT_TRUE(sum % 10 == 0);
+}
+
+TEST_F(CommerceTest, shouldGenerateIsbn13)
+{
+    const auto generatedIsbn13 = Commerce::ISBN13();
+    
+    int sum = 0;
+    for (size_t i = 0; i < 13; i++)
+    {
+        if (i % 2 == 0) {
+            sum += (generatedIsbn13[i] - '0');
+        }
+        else {
+            sum += 3 * (generatedIsbn13[i] - '0');
+        }
+    }
+
+    ASSERT_EQ(generatedIsbn13.size(), 13);
+    ASSERT_TRUE(sum % 10 == 0);
+}
+
+TEST_F(CommerceTest, shouldGenerateIsbn10)
+{
+    const auto generatedIsbn10 = Commerce::ISBN10();
+    
+    int sum = 0, weight = 10;
+    if (generatedIsbn10[9] == 'X') {
+        for (size_t i = 0; i < 9; i++)
+        {
+            sum += (generatedIsbn10[i] - '0') * weight;
+            weight--;
+        }
+        sum += 10;
+    }
+    else {
+        for (size_t i = 0; i < 10; i++)
+        {
+            sum += (generatedIsbn10[i] - '0') * weight;
+            weight--;
+        }
+    }
+
+    ASSERT_EQ(generatedIsbn10.size(), 10);
+    ASSERT_TRUE(sum % 11 == 0);
+}