// RepeatSetProxy.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <windows.h>
#include <WinInet.h>
#include <iostream>
#include <strsafe.h>
#include <cstring>
#include <atlstr.h>

BOOL SetConnectionProxyOptions(LPWSTR proxyServerAddr);
wchar_t* convertCharArrayToLPCWSTR(const char* charArray);
void PrintErrorMessage(LPTSTR lpszFunction);

int main(int argc, char* argv[])
{
    std::cout << "Welcome to ProxyShooter!" << std::endl;
    if (argc != 2) {
        std::cout << "Usage: ProxyShooter.exe 127.0.0.1:11884" << std::endl;
        return 5;
    }
    const char* servAddr = argv[1];
    std::cout << "Received Server: " << servAddr << std::endl;
    LPWSTR wPtrServ = convertCharArrayToLPCWSTR(servAddr);
    while (TRUE) {
        BOOL res = SetConnectionProxyOptions(wPtrServ);
        if (res != TRUE) {
            // if set repeated params, it will return FALSE, but still working.
            PrintErrorMessage(LPTSTR(TEXT("SetConnectionProxyOptions")));
        }
        std::cout << "Set OK!" << std::endl;
        InternetSetOption(NULL, INTERNET_OPTION_SETTINGS_CHANGED, NULL, 0);
        InternetSetOption(NULL, INTERNET_OPTION_REFRESH, NULL, 0);
        Sleep(1000);
    }
    return 0;
}

BOOL SetConnectionProxyOptions(LPWSTR proxyServerAddr)
{
    INTERNET_PER_CONN_OPTION_LIST conn_options;
    BOOL bReturn;
    DWORD dwBufferSize = sizeof(conn_options);

    {
        conn_options.dwSize = dwBufferSize;
        conn_options.pszConnection = NULL;
        conn_options.dwOptionCount = 3;
        conn_options.pOptions = (INTERNET_PER_CONN_OPTION*)malloc(
            sizeof(INTERNET_PER_CONN_OPTION) * conn_options.dwOptionCount);
        conn_options.pOptions[0].dwOption = INTERNET_PER_CONN_FLAGS;
        conn_options.pOptions[0].Value.dwValue = PROXY_TYPE_DIRECT | PROXY_TYPE_PROXY;
        conn_options.pOptions[1].dwOption = INTERNET_PER_CONN_PROXY_SERVER;
        conn_options.pOptions[1].Value.pszValue = proxyServerAddr;
        conn_options.pOptions[2].dwOption = INTERNET_PER_CONN_PROXY_BYPASS;
        conn_options.pOptions[2].Value.pszValue = (LPWSTR)L"<local>;*.lan;*.local;127.*;172.16.*;10.*;192.168.*;localhost";
    }

    bReturn = InternetSetOption(NULL, INTERNET_OPTION_PER_CONNECTION_OPTION, &conn_options, dwBufferSize);
    free(conn_options.pOptions);

    return bReturn;
}

wchar_t* convertCharArrayToLPCWSTR(const char* charArray)
{
    wchar_t* wString = new wchar_t[1024];
    MultiByteToWideChar(CP_ACP, 0, charArray, -1, wString, 1024);
    return wString;
}

void PrintErrorMessage(LPTSTR lpszFunction) {
    LPVOID lpMsgBuf;
    LPVOID lpDisplayBuf;
    DWORD dw = GetLastError();

    FormatMessage(
        FORMAT_MESSAGE_ALLOCATE_BUFFER |
        FORMAT_MESSAGE_FROM_SYSTEM |
        FORMAT_MESSAGE_IGNORE_INSERTS,
        NULL,
        dw,
        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
        (LPTSTR)&lpMsgBuf,
        0, NULL);

    // Display the error message and exit the process
    lpDisplayBuf = (LPVOID)LocalAlloc(LMEM_ZEROINIT,
        (lstrlen((LPCTSTR)lpMsgBuf) + lstrlen((LPCTSTR)lpszFunction) + 40) * sizeof(TCHAR));
    StringCchPrintf((LPTSTR)lpDisplayBuf,
        LocalSize(lpDisplayBuf) / sizeof(TCHAR),
        TEXT("%s failed with error %d: %s"),
        lpszFunction, dw, lpMsgBuf);
    std::wcout << "ReturnVal: False, Error: " << (LPTSTR)lpDisplayBuf << std::endl;
    LocalFree(lpMsgBuf);
    LocalFree(lpDisplayBuf);
}