#define WIN32_LEAN_AND_MEAN
#include <Windows.h>
#include <TlHelp32.h>
#include <filesystem>
#include <sstream>
#include <fstream>
#include <Shlwapi.h>

namespace fs = std::filesystem;

extern "C" {
    __declspec(dllexport) DWORD AmdPowerXpressRequestHighPerformance = 0x00000001;
    __declspec(dllexport) DWORD NvOptimusEnablement = 0x00000001;
}

HMODULE hLauncherModule;
HMODULE hHookModule;
HMODULE hTier0Module;

wchar_t exePath[4096];
wchar_t buffer[8192];

DWORD GetProcessByName(std::wstring processName)
{
    HANDLE snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);

    PROCESSENTRY32 processSnapshotEntry = { 0 };
    processSnapshotEntry.dwSize = sizeof(PROCESSENTRY32);

    if (snapshot == INVALID_HANDLE_VALUE)
        return 0;

    if (!Process32First(snapshot, &processSnapshotEntry))
        return 0;

    while (Process32Next(snapshot, &processSnapshotEntry))
    {
        if (!wcscmp(processSnapshotEntry.szExeFile, processName.c_str()))
        {
            CloseHandle(snapshot);
            return processSnapshotEntry.th32ProcessID;
        }
    }

    CloseHandle(snapshot);
    return 0;
}

bool GetExePathWide(wchar_t* dest, DWORD destSize)
{
    if (!dest) return NULL;
    if (destSize < MAX_PATH) return NULL;

    DWORD length = GetModuleFileNameW(NULL, dest, destSize);
    return length && PathRemoveFileSpecW(dest);
}

FARPROC GetLauncherMain()
{
    static FARPROC Launcher_LauncherMain;
    if (!Launcher_LauncherMain)
        Launcher_LauncherMain = GetProcAddress(hLauncherModule, "LauncherMain");
    return Launcher_LauncherMain;
}

void LibraryLoadError(DWORD dwMessageId, const wchar_t* libName, const wchar_t* location)
{
    char text[8192];
    std::string message = std::system_category().message(dwMessageId);
    
    sprintf_s(text, "Failed to load the %ls at \"%ls\" (%lu):\n\n%hs\n\nMake sure you followed the Northstar installation instructions carefully before reaching out for help.", libName, location, dwMessageId, message.c_str());
    
    if (dwMessageId == 126 && std::filesystem::exists(location))
    {
        sprintf_s(text, "%s\n\nThe file at the specified location DOES exist, so this error indicates that one of its *dependencies* failed to be found.\n\nTry the following steps:\n1. Install Visual C++ 2022 Redistributable: https://aka.ms/vs/17/release/vc_redist.x64.exe\n2. Repair game files", text);
    }
    else if (!fs::exists("Titanfall2.exe") && (fs::exists("..\\Titanfall2.exe") || fs::exists("..\\..\\Titanfall2.exe")))
    {
        auto curDir = std::filesystem::current_path().filename().string();
        auto aboveDir = std::filesystem::current_path().parent_path().filename().string();
        sprintf_s(text, "%s\n\nWe detected that in your case you have extracted the files into a *subdirectory* of your Titanfall 2 installation.\nPlease move all the files and folders from current folder (\"%s\") into the Titanfall 2 installation directory just above (\"%s\").\n\nPlease try out the above steps by yourself before reaching out to the community for support.", text, curDir.c_str(), aboveDir.c_str());
    }
    else if (!fs::exists("Titanfall2.exe"))
    {
        sprintf_s(text, "%s\n\nRemember: you need to unpack the contents of this archive into your Titanfall 2 game installation directory, not just to any random folder.", text);
    }
    else if (fs::exists("Titanfall2.exe"))
    {
        sprintf_s(text, "%s\n\nTitanfall2.exe has been found in the current directory: is the game installation corrupted or did you not unpack all Northstar files here?", text);
    }

    MessageBoxA(GetForegroundWindow(), text, "Northstar Launcher Error", 0);
}

void EnsureOriginStarted()
{
    if (GetProcessByName(L"Origin.exe") || GetProcessByName(L"EADesktop.exe"))
        return; // already started

    // unpacked exe will crash if origin isn't open on launch, so launch it
    // get origin path from registry, code here is reversed from OriginSDK.dll
    HKEY key;
    if (RegOpenKeyExA(HKEY_LOCAL_MACHINE, "SOFTWARE\\WOW6432Node\\Origin", 0, KEY_READ, &key) != ERROR_SUCCESS)
    {
        MessageBoxA(0, "Error: failed reading Origin path!", "Northstar Launcher Error", MB_OK);
        return;
    }

    char originPath[520];
    DWORD originPathLength = 520;
    if (RegQueryValueExA(key, "ClientPath", 0, 0, (LPBYTE)&originPath, &originPathLength) != ERROR_SUCCESS)
    {
        MessageBoxA(0, "Error: failed reading Origin path!", "Northstar Launcher Error", MB_OK);
        return;
    }

    PROCESS_INFORMATION pi;
    memset(&pi, 0, sizeof(pi));
    STARTUPINFO si;
    memset(&si, 0, sizeof(si));
    CreateProcessA(originPath, (char*)"", NULL, NULL, false, CREATE_DEFAULT_ERROR_MODE | CREATE_NEW_PROCESS_GROUP, NULL, NULL, (LPSTARTUPINFOA)&si, &pi);

    printf("[*] Waiting for Origin...\n");

    // wait for origin to be ready, this process is created when origin is ready enough to launch game without any errors
    while (!GetProcessByName(L"OriginClientService.exe") && !GetProcessByName(L"EADesktop.exe"))
        Sleep(200);

    CloseHandle(pi.hProcess);
    CloseHandle(pi.hThread);
}

void PrependPath()
{
    wchar_t* pPath;
    size_t len;
    errno_t err = _wdupenv_s(&pPath, &len, L"PATH");
    if (!err)
    {
        swprintf_s(buffer, L"PATH=%s\\bin\\x64_retail\\;%s", exePath, pPath);
        auto result = _wputenv(buffer);
        if (result == -1)
        {
            MessageBoxW(GetForegroundWindow(), L"Warning: could not prepend the current directory to app's PATH environment variable. Something may break because of that.", L"Northstar Launcher Warning", 0);
        }
        free(pPath);
    }
    else
    {
        MessageBoxW(GetForegroundWindow(), L"Warning: could not get current PATH environment variable in order to prepend the current directory to it. Something may break because of that.", L"Northstar Launcher Warning", 0);
    }
}

bool ShouldLoadNorthstar(int argc, char* argv[])
{
    bool loadNorthstar = true;
    for (int i = 0; i < argc; i++)
        if (!strcmp(argv[i], "-vanilla"))
            loadNorthstar = false;

    if (!loadNorthstar)
        return loadNorthstar;

    auto runNorthstarFile = std::ifstream("run_northstar.txt");
    if (runNorthstarFile)
    {
        std::stringstream runNorthstarFileBuffer;
        runNorthstarFileBuffer << runNorthstarFile.rdbuf();
        runNorthstarFile.close();
        if (runNorthstarFileBuffer.str()._Starts_with("0"))
            loadNorthstar = false;
    }
    return loadNorthstar;
}

bool LoadNorthstar()
{
    FARPROC Hook_Init = nullptr;
    {
        swprintf_s(buffer, L"%s\\Northstar.dll", exePath);
        hHookModule = LoadLibraryExW(buffer, 0i64, 8u);
        if (hHookModule) Hook_Init = GetProcAddress(hHookModule, "InitialiseNorthstar");
        if (!hHookModule || Hook_Init == nullptr)
        {
            LibraryLoadError(GetLastError(), L"Northstar.dll", buffer);
            return false;
        }
    }

    ((bool (*)()) Hook_Init)();
    return true;
}

int main(int argc, char* argv[]) {

    // checked to avoid starting origin, Northstar.dll will check for -dedicated as well on its own
    bool noOriginStartup = false;
    for (int i = 0; i < argc; i++)
        if (!strcmp(argv[i], "-noOriginStartup") || !strcmp(argv[i], "-dedicated"))
            noOriginStartup = true;

    if (!noOriginStartup)
    {
        EnsureOriginStarted();
    }

    {
        if (!GetExePathWide(exePath, sizeof(exePath)))
        {
            MessageBoxA(GetForegroundWindow(), "Failed getting game directory.\nThe game cannot continue and has to exit.", "Northstar Launcher Error", 0);
            return 1;
        }

        PrependPath();

        printf("[*] Loading tier0.dll\n");
        swprintf_s(buffer, L"%s\\bin\\x64_retail\\tier0.dll", exePath);
        hTier0Module = LoadLibraryExW(buffer, 0, LOAD_WITH_ALTERED_SEARCH_PATH);
        if (!hTier0Module)
        {
            LibraryLoadError(GetLastError(), L"tier0.dll", buffer);
            return 1;
        }

        bool loadNorthstar = ShouldLoadNorthstar(argc, argv);
        if (loadNorthstar)
        {
            printf("[*] Loading Northstar\n");
            if (!LoadNorthstar())
                return 1;
        }
        else
            printf("[*] Going to load the vanilla game\n");

        printf("[*] Loading launcher.dll\n");
        swprintf_s(buffer, L"%s\\bin\\x64_retail\\launcher.dll", exePath);
        hLauncherModule = LoadLibraryExW(buffer, 0, LOAD_WITH_ALTERED_SEARCH_PATH);
        if (!hLauncherModule)
        {
            LibraryLoadError(GetLastError(), L"launcher.dll", buffer);
            return 1;
        }
    }

    printf("[*] Launching the game...\n");
    auto LauncherMain = GetLauncherMain();
    if (!LauncherMain)
        MessageBoxA(GetForegroundWindow(), "Failed loading launcher.dll.\nThe game cannot continue and has to exit.", "Northstar Launcher Error", 0);
    //auto result = ((__int64(__fastcall*)())LauncherMain)();
    //auto result = ((signed __int64(__fastcall*)(__int64))LauncherMain)(0i64);
    return ((int(/*__fastcall*/*)(HINSTANCE, HINSTANCE, LPSTR, int))LauncherMain)(NULL, NULL, NULL, 0); // the parameters aren't really used anyways
}