feat: enhance validation and serialization with fiscal code checks and JSON schema support

common/Validation.cc

@@ -1,9 +1,44 @@
 #include "common/Validation.h"
 
+#include <array>
+#include <cctype>
 #include <regex>
 
 namespace visione::validation
 {
+namespace
+{
+char normalizeFiscalCodeChar(char ch)
+{
+    return static_cast<char>(
+        std::toupper(static_cast<unsigned char>(ch)));
+}
+
+int fiscalCodeControlValueForOdd(char ch)
+{
+    static constexpr std::array<int, 26> letterValues{
+        1, 0, 5, 7, 9, 13, 15, 17, 19, 21, 2, 4, 18,
+        20, 11, 3, 6, 8, 12, 14, 16, 10, 22, 25, 24, 23};
+    static constexpr std::array<int, 10> digitValues{1, 0, 5, 7, 9,
+                                                      13, 15, 17, 19, 21};
+
+    if (std::isdigit(static_cast<unsigned char>(ch)))
+    {
+        return digitValues[static_cast<size_t>(ch - '0')];
+    }
+    return letterValues[static_cast<size_t>(ch - 'A')];
+}
+
+int fiscalCodeControlValueForEven(char ch)
+{
+    if (std::isdigit(static_cast<unsigned char>(ch)))
+    {
+        return ch - '0';
+    }
+    return ch - 'A';
+}
+}  // namespace
+
 bool hasString(const Json::Value &body, const std::string &key)
 {
     return body.isMember(key) && body[key].isString() &&
@@ -38,8 +73,30 @@ bool isValidEmail(const std::string &email)
 
 bool isValidFiscalCode(const std::string &fiscalCode)
 {
-    static const std::regex pattern(R"(^[A-Za-z0-9]{16}$)");
-    return std::regex_match(fiscalCode, pattern);
+    static const std::regex pattern(
+        R"(^[A-Za-z]{6}[0-9]{2}[ABCDEHLMPRST]{1}[0-9]{2}[A-Za-z][0-9]{3}[A-Za-z]$)");
+
+    if (!std::regex_match(fiscalCode, pattern))
+    {
+        return false;
+    }
+
+    std::string normalized;
+    normalized.reserve(fiscalCode.size());
+    for (char ch : fiscalCode)
+    {
+        normalized.push_back(normalizeFiscalCodeChar(ch));
+    }
+
+    int sum = 0;
+    for (size_t i = 0; i < normalized.size() - 1; ++i)
+    {
+        sum += ((i + 1) % 2 == 0) ? fiscalCodeControlValueForEven(normalized[i])
+                                  : fiscalCodeControlValueForOdd(normalized[i]);
+    }
+
+    const char expectedControl =
+        static_cast<char>('A' + (sum % 26));
+    return normalized.back() == expectedControl;
 }
 }  // namespace visione::validation
-