/* Main program when embedded in a UWP application on Windows */

#include "Python.h"
#include <string.h>

#define WIN32_LEAN_AND_MEAN
#include <Windows.h>
#include <shellapi.h>
#include <shlobj.h>

#include <string>

#include <winrt\Windows.ApplicationModel.h>
#include <winrt\Windows.Storage.h>

#ifdef PYTHONW
#ifdef _DEBUG
const wchar_t *PROGNAME = L"pythonw_d.exe";
#else
const wchar_t *PROGNAME = L"pythonw.exe";
#endif
#else
#ifdef _DEBUG
const wchar_t *PROGNAME = L"python_d.exe";
#else
const wchar_t *PROGNAME = L"python.exe";
#endif
#endif

static std::wstring
get_user_base()
{
 try {
 const auto appData = winrt::Windows::Storage::ApplicationData::Current();
 if (appData) {
 const auto localCache = appData.LocalCacheFolder();
 if (localCache) {
 auto path = localCache.Path();
 if (!path.empty()) {
 return std::wstring(path) + L"\\local-packages";
 }
 }
 }
 } catch (...) {
 }
 return std::wstring();
}

static std::wstring
get_package_family()
{
 try {
 const auto package = winrt::Windows::ApplicationModel::Package::Current();
 if (package) {
 const auto id = package.Id();
 if (id) {
 return std::wstring(id.FamilyName());
 }
 }
 }
 catch (...) {
 }

 return std::wstring();
}

static std::wstring
get_package_home()
{
 try {
 const auto package = winrt::Windows::ApplicationModel::Package::Current();
 if (package) {
 const auto path = package.InstalledLocation();
 if (path) {
 return std::wstring(path.Path());
 }
 }
 }
 catch (...) {
 }

 return std::wstring();
}

static int
set_process_name()
{
 const auto home = get_package_home();
 const auto family = get_package_family();

 std::wstring executable;

 /* If inside a package, use user's symlink name for executable */
 if (!family.empty()) {
 PWSTR localAppData;
 if (SUCCEEDED(SHGetKnownFolderPath(FOLDERID_LocalAppData, 0,
 NULL, &localAppData))) {
 executable = std::wstring(localAppData)
 + L"\\Microsoft\\WindowsApps\\"
 + family
 + L"\\"
 + PROGNAME;

 CoTaskMemFree(localAppData);
 }
 }

 /* Only use module filename if we don't have a home */
 if (home.empty() && executable.empty()) {
 executable.resize(MAX_PATH);
 while (true) {
 DWORD len = GetModuleFileNameW(
 NULL, executable.data(), (DWORD)executable.size());
 if (len == 0) {
 executable.clear();
 break;
 } else if (len == executable.size() &&
 GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
 executable.resize(len * 2);
 } else {
 executable.resize(len);
 break;
 }
 }
 }

 if (!home.empty()) {
 Py_SetPythonHome(home.c_str());
 }

 const wchar_t *launcherPath = _wgetenv(L"__PYVENV_LAUNCHER__");
 if (launcherPath) {
 if (!executable.empty()) {
 _wputenv_s(L"__PYVENV_BASE_EXECUTABLE__", executable.c_str());
 }
 _Py_SetProgramFullPath(launcherPath);
 /* bpo-35873: Clear the environment variable to avoid it being
 * inherited by child processes. */
 _wputenv_s(L"__PYVENV_LAUNCHER__", L"");
 } else if (!executable.empty()) {
 _Py_SetProgramFullPath(executable.c_str());
 }

 return 1;
}

int
wmain(int argc, wchar_t **argv)
{
 if (!set_process_name()) {
 return 121;
 }
 const wchar_t *p = _wgetenv(L"PYTHONUSERBASE");
 if (!p || !*p) {
 _wputenv_s(L"PYTHONUSERBASE", get_user_base().c_str());
 }

 p = wcsrchr(argv[0], L'\\');
 if (!p) {
 p = argv[0];
 }
 if (p) {
 if (*p == L'\\') {
 p++;
 }

 const wchar_t *moduleName = NULL;
 if (wcsnicmp(p, L"pip", 3) == 0) {
 moduleName = L"pip";
 /* No longer required when pip 19.1 is added */
 _wputenv_s(L"PIP_USER", L"true");
 } else if (wcsnicmp(p, L"idle", 4) == 0) {
 moduleName = L"idlelib";
 }

 if (moduleName) {
 /* Not even pretending we're going to free this memory.
 * The OS will clean it all up when our process exits
 */
 wchar_t **new_argv = (wchar_t **)PyMem_RawMalloc((argc + 2) * sizeof(wchar_t *));
 new_argv[0] = argv[0];
 new_argv[1] = _PyMem_RawWcsdup(L"-m");
 new_argv[2] = _PyMem_RawWcsdup(moduleName);
 for (int i = 1; i < argc; ++i) {
 new_argv[i + 2] = argv[i];
 }
 argv = new_argv;
 argc += 2;
 }
 }

 return Py_Main(argc, (wchar_t**)argv);
}

#ifdef PYTHONW

int WINAPI wWinMain(
 HINSTANCE hInstance, /* handle to current instance */
 HINSTANCE hPrevInstance, /* handle to previous instance */
 LPWSTR lpCmdLine, /* pointer to command line */
 int nCmdShow /* show state of window */
)
{
 return wmain(__argc, __wargv);
}

#endif