/**
 * @brief The RegistryCRUD.cpp program demonstrates how to perform basic operations on the Windows Registry using the native API.
 * The program performs the following CRUD (Create, Read, Update, Delete) operations on a registry key:
 * Open Key: It opens a registry key for the current user's application settings.
 * Create Value: It creates a new registry value with the name "MySetting" and sets its data to "MyValue".
 * Read Value: It reads the value of "MySetting" from the registry and prints it.
 * Modify Value: It modifies the value of "MySetting" to "MyNewValue".
 * Delete Value: It deletes the value of "MySetting" from the registry.
 *
 * @author Yavuz Sava (woose)
 * @date 13/12/2024
 */

#include <windows.h>
#include <iostream>
using namespace std;
// Open a registry key using the native API.
HKEY OpenKey(HKEY hKey, LPCWSTR subKey, DWORD dwOptions)
{
    HKEY hOpenKey = NULL;
    if (RegOpenKeyEx(hKey, subKey, 0, KEY_READ | KEY_WRITE, &hOpenKey) != ERROR_SUCCESS)
    {
        cerr << "Error opening registry key." << endl;
        return NULL;
    }
    return hOpenKey;
}
// Create a new registry value.
void CreateValue(HKEY hKey, LPCWSTR valueName, LPCWSTR valueData)
{
    if (RegSetValueEx(hKey, valueName, 0, REG_SZ, (const BYTE *)valueData, (DWORD)(wcslen(valueData) * sizeof(WCHAR))) != ERROR_SUCCESS)
    {
        cerr << "Error creating registry value." << endl;
    }
}
// Read a registry value.
void ReadValue(HKEY hKey, LPCWSTR valueName)
{
    DWORD dwType = REG_SZ;
    WCHAR szBuffer[256];
    DWORD dwSize = sizeof(szBuffer);
    if (RegQueryValueEx(hKey, valueName, NULL, &dwType, (LPBYTE)szBuffer, &dwSize) != ERROR_SUCCESS)
    {
        cerr << "Error reading registry value." << endl;
    }
    else
    {
        wcout << valueName << L": " << szBuffer << endl;
    }
}
// Modify a registry value.
void ModifyValue(HKEY hKey, LPCWSTR valueName, LPCWSTR valueData)
{
    if (RegSetValueEx(hKey, valueName, 0, REG_SZ, (const BYTE *)valueData, (DWORD)(wcslen(valueData) * sizeof(WCHAR))) != ERROR_SUCCESS)
    {
        cerr << "Error modifying registry value." << endl;
    }
}
// Delete a registry value.
void DeleteValue(HKEY hKey, LPCWSTR valueName)
{
    if (RegDeleteValue(hKey, valueName) != ERROR_SUCCESS)
    {
        cerr << "Error deleting registry value." << endl;
    }
}
int main()
{
    // Open the registry key for the current user's application settings.
    HKEY hAppSettings = OpenKey(HKEY_CURRENT_USER, L"Software\\MyCompany\\MyApplication", 0);
    if (hAppSettings == NULL)
    {
        return 1;
    }
    // Create a new registry value.
    CreateValue(hAppSettings, L"MySetting", L"MyValue");
    // Read the registry value.
    ReadValue(hAppSettings, L"MySetting");
    // Modify the registry value.
    ModifyValue(hAppSettings, L"MySetting", L"MyNewValue");
    // Delete the registry value.
    DeleteValue(hAppSettings, L"MySetting");
    // Close the registry key.
    RegCloseKey(hAppSettings);
    return 0;
}