// TortoiseSVN - a Windows shell extension for easy version control

// Copyright (C) 2009-2010, 2013, 2021 - TortoiseSVN

// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software Foundation,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//
#pragma once

/**
 * A helper class for invoking CreateProcess(). The lpProcessInformation
 * can point to an uninitialized struct - it's memset to all zeroes inside.
 */

class CCreateProcessHelper
{
public:
    static bool CreateProcess(LPCWSTR               lpApplicationName,
                              LPCWSTR               lpCommandLine,
                              LPCWSTR               lpCurrentDirectory,
                              LPPROCESS_INFORMATION lpProcessInformation);
    static bool CreateProcess(LPCWSTR               lpApplicationName,
                              LPCWSTR               lpCommandLine,
                              LPPROCESS_INFORMATION lpProcessInformation);

    static bool CreateProcessDetached(LPCWSTR lpApplicationName,
                                      LPCWSTR lpCommandLine,
                                      LPCWSTR lpCurrentDirectory);
    static bool CreateProcessDetached(LPCWSTR lpApplicationName,
                                      LPCWSTR lpCommandLine);
};

inline bool CCreateProcessHelper::CreateProcess(LPCWSTR applicationName,
                                                LPCWSTR commandLine, LPCWSTR currentDirectory,
                                                LPPROCESS_INFORMATION processInfo)
{
    STARTUPINFO startupInfo = {0};
    startupInfo.cb          = sizeof(STARTUPINFO);

    SecureZeroMemory(processInfo, sizeof(PROCESS_INFORMATION));

    // CreateProcess may modify buffer specified by lpCommandLine:
    // https://msdn.microsoft.com/en-us/library/windows/desktop/ms682425
    // [[
    // The Unicode version of this function, CreateProcessW, can modify
    // the contents of this string.Therefore, this parameter cannot be a
    // pointer to read - only memory(such as a const variable or a literal
    // string).If this parameter is a constant string, the function may
    // cause an access violation.
    // ]]
    LPWSTR commandLineBuf;
    if (commandLine)
    {
        commandLineBuf = _wcsdup(commandLine);
    }
    else
    {
        commandLineBuf = nullptr;
    }

    const BOOL result = ::CreateProcess(applicationName,
                                        commandLineBuf, nullptr, nullptr, FALSE, CREATE_UNICODE_ENVIRONMENT, nullptr, currentDirectory,
                                        &startupInfo, processInfo);

    if (commandLineBuf)
        free(commandLineBuf);

    return result != 0;
}

inline bool CCreateProcessHelper::CreateProcess(LPCWSTR applicationName,
                                                LPCWSTR commandLine, LPPROCESS_INFORMATION processInformation)
{
    return CreateProcess(applicationName, commandLine, nullptr, processInformation);
}

inline bool CCreateProcessHelper::CreateProcessDetached(LPCWSTR lpApplicationName,
                                                        LPCWSTR lpCommandLine, LPCWSTR lpCurrentDirectory)
{
    PROCESS_INFORMATION process;
    if (!CreateProcess(lpApplicationName, lpCommandLine, lpCurrentDirectory, &process))
        return false;

    CloseHandle(process.hThread);
    CloseHandle(process.hProcess);
    return true;
}

inline bool CCreateProcessHelper::CreateProcessDetached(LPCWSTR lpApplicationName,
                                                        LPCWSTR lpCommandLine)
{
    return CreateProcessDetached(lpApplicationName, lpCommandLine, nullptr);
}