#include <windows.h>
#include <TlHelp32.h>
#include <iostream>

typedef unsigned char uint8_t;

template <typename T, size_t N>

size_t countof(T(&array)[N])
{
    return N;
}

DWORD dwLocalPlayer; //will be scanned
DWORD dwEntityList;  //will be scanned
DWORD dwGlow;        //will be scanned

DWORD dwTeam = 0xF0;
DWORD dwDormant = 0xE9;

struct PModule
{
    DWORD dwBase;
    DWORD dwSize;
};

/* Debugger/Process API implementation class */
class process
{

public:
    bool Attach(char* pName, DWORD rights)
    {
        HANDLE handle = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, NULL);
        PROCESSENTRY32 entry;
        entry.dwSize = sizeof(entry);

        do
            if (!strcmp(entry.szExeFile, pName)) {
                pID = entry.th32ProcessID;
                CloseHandle(handle);
                _process = OpenProcess(rights, false, pID);
                return true;
            }
        while (Process32Next(handle, &entry));
        return false;
    }
    PModule GetModule(char* moduleName) {
        HANDLE module = CreateToolhelp32Snapshot(TH32CS_SNAPMODULE, pID);
        MODULEENTRY32 mEntry;
        mEntry.dwSize = sizeof(mEntry);

        do {
            if (!strcmp(mEntry.szModule, (LPSTR)moduleName)) {
                CloseHandle(module);

                PModule mod = { (DWORD)mEntry.hModule, mEntry.modBaseSize };
                return mod;
            }
        } while (Module32Next(module, &mEntry));

        PModule mod = { (DWORD)false, (DWORD)false };
        return mod;
    }

    template <class T>
    T Read(DWORD addr) {
        T _read;
        ReadProcessMemory(_process, (LPVOID)addr, &_read, sizeof(T), NULL);
        return _read;
    }
    template <class T>
    void Write(DWORD addr, T val) {
        WriteProcessMemory(_process, (LPVOID)addr, &val, sizeof(T), NULL);
    }

    DWORD FindPattern(DWORD start, DWORD size, const char* sig, const char* mask) {
        BYTE* data = new BYTE[size];

        unsigned long bytesRead;
        if (!ReadProcessMemory(_process, (LPVOID)start, data, size, &bytesRead)) {
            return NULL;
        }

        for (DWORD i = 0; i < size; i++) {
            if (DataCompare((const BYTE*)(data + i), (const BYTE*)sig, mask)) {
                return start + i;
            }
        }
        return NULL;
    }

    DWORD FindPatternArray(DWORD start, DWORD size, const char* mask, int count, ...) {
        char* sig = new char[count + 1];
        va_list ap;
        va_start(ap, count);
        for (int i = 0; i < count; i++) {
            char read = va_arg(ap, char);
            sig[i] = read;
        }
        va_end(ap);
        sig[count] = '\0';
        return FindPattern(start, size, sig, mask);
    }


private:
    HANDLE _process;
    DWORD pID;
    bool DataCompare(const BYTE* pData, const BYTE* pMask, const char* pszMask) {
        for (; *pszMask; ++pszMask, ++pData, ++pMask) {
            if (*pszMask == 'x' && *pData != *pMask) {
                return false;
            }
        }
        return (*pszMask == NULL);
    }
};

/* Glow Object structure in csgo */
struct glow_t
{
    DWORD dwBase;
    float r;
    float g;
    float b;
    float a;
    uint8_t unk1[16];
    bool m_bRenderWhenOccluded;
    bool m_bRenderWhenUnoccluded;
    bool m_bFullBloom;
    uint8_t unk2[10];
};

/* Entity structure in csgo */
struct Entity
{
    DWORD dwBase;
    int team;
    bool is_dormant;
};

/* Player structure in csgo */
struct Player
{
    DWORD dwBase;
    bool isDormant;
};

process memory;
process _modClient;
process* mem;
PModule modClient;

int iFriendlies;
int iEnemies;

Entity entEnemies[32];
Entity entFriendlies[32];
Entity me;

void update_entity_data(Entity* e, DWORD dwBase)
{
    int dormant = memory.Read<int>(dwBase + dwDormant);
    e->dwBase = dwBase;
    e->team = memory.Read<int>(dwBase + dwTeam);
    e->is_dormant = dormant == 1;
}
/* Get Pointer To Client.dll*/
PModule* GetClientModule() {
    if (modClient.dwBase == 0 && modClient.dwSize == 0) {
        modClient = memory.GetModule("client.dll");
    }
    return &modClient;
}

Entity* GetEntityByBase(DWORD dwBase) {

    for (int i = 0; i < iFriendlies; i++) {
        if (dwBase == entFriendlies[i].dwBase) {
            return &entFriendlies[i];
        }
    }
    for (int i = 0; i < iEnemies; i++) {
        if (dwBase == entEnemies[i].dwBase) {
            return &entEnemies[i];
        }
    }
    return nullptr;
}

/* offset updating class, that uses patterns to find memory addresses */
class offset
{
private:
    static void update_local_player() {
        DWORD lpStart = mem->FindPatternArray(modClient.dwBase, modClient.dwSize, "xxx????xx????xxxxx?", 19, 0x8D, 0x34, 0x85, 0x0, 0x0, 0x0, 0x0, 0x89, 0x15, 0x0, 0x0, 0x0, 0x0, 0x8B, 0x41, 0x8, 0x8B, 0x48, 0x0);
        DWORD lpP1 = mem->Read<DWORD>(lpStart + 3);
        BYTE lpP2 = mem->Read<BYTE>(lpStart + 18);
        dwLocalPlayer = (lpP1 + lpP2) - modClient.dwBase;
    }

    static void update_entity_list() {
        DWORD elStart = mem->FindPatternArray(modClient.dwBase, modClient.dwSize, "x????xx?xxx", 11, 0x5, 0x0, 0x0, 0x0, 0x0, 0xC1, 0xE9, 0x0, 0x39, 0x48, 0x4);
        DWORD elP1 = mem->Read<DWORD>(elStart + 1);
        BYTE elP2 = mem->Read<BYTE>(elStart + 7);
        dwEntityList = (elP1 + elP2) - modClient.dwBase;
    }

    static void update_glow() {
        DWORD gpStart = mem->FindPatternArray(modClient.dwBase, modClient.dwSize, "xx????x????xxx????xx????xx", 27, 0x8D, 0x8F, 0, 0, 0, 0, 0xA1, 0, 0, 0, 0, 0xC7, 0x4, 0x2, 0, 0, 0, 0, 0x89, 0x35, 0x0, 0x0, 0x0, 0x0, 0x8B, 0x51);
        dwGlow = mem->Read<DWORD>(gpStart + 7) - modClient.dwBase;
    }
public:
    static void get_offset(process* m) {
        mem = m;
        modClient = mem->GetModule("client.dll");
        update_local_player();
        update_entity_list();
        update_glow();
    }

    //constantly scanning & updating our offsets
    static DWORD WINAPI scan_offsets(LPVOID PARAM)
    {
        Entity players[64];
        while (true) {
            DWORD playerBase = memory.Read<DWORD>(GetClientModule()->dwBase + dwLocalPlayer);
            int cp = 0;

            update_entity_data(&me, playerBase);
            for (int i = 1; i < 64; i++) {
                DWORD entBase = memory.Read<DWORD>((GetClientModule()->dwBase + dwEntityList) + i * 0x10);

                if (entBase == NULL)
                    continue;

                update_entity_data(&players[cp], entBase);

                cp++;
            }

            int cf = 0, ce = 0;

            for (int i = 0; i < cp; i++) {
                if (players[i].team == me.team) {
                    entFriendlies[cf] = players[i];
                    cf++;
                }
                else {
                    entEnemies[ce] = players[i];
                    ce++;
                }
            }
            iEnemies = ce;
            iFriendlies = cf;
        }
    }
};


class virtualesp
{
private:
    static void glow_player(DWORD mObj, float r, float g, float b)
    {
        memory.Write<float>(mObj + 0x4, r);
        memory.Write<float>(mObj + 0x8, g);
        memory.Write<float>(mObj + 0xC, b);
        memory.Write<float>(mObj + 0x10, 1.0f);
        memory.Write<BOOL>(mObj + 0x24, true);
        memory.Write<BOOL>(mObj + 0x25, false);
    }

    static float SanitizeColor(int value)
    {
        if (value > 255) value = 255;
        if (value < 0) value = 0;
        return (float)value / 255;
    }
public:
    static void start_engine() {
        while (!memory.Attach("csgo.exe", PROCESS_ALL_ACCESS)) {
            Sleep(100);
        }
        do {
            Sleep(1000);
            offset::get_offset(&memory);
        } while (dwLocalPlayer < 65535);
        CreateThread(NULL, NULL, &offset::scan_offsets, NULL, NULL, NULL);
    }

    static unsigned long __stdcall esp_thread(void*)
    {
        int objectCount;
        DWORD pointerToGlow;
        Entity* Player = NULL;
        float Friend = SanitizeColor(100);
        float Enemy = SanitizeColor(140);

        while (true)
        {
            pointerToGlow = memory.Read<DWORD>(GetClientModule()->dwBase + dwGlow);
            objectCount = memory.Read<DWORD>(GetClientModule()->dwBase + dwGlow + 0x4);
            if (pointerToGlow != NULL && objectCount > 0)
            {
                for (int i = 0; i < objectCount; i++)
                {
                    DWORD mObj = pointerToGlow + i * sizeof(glow_t);
                    glow_t glowObject = memory.Read<glow_t>(mObj);
                    Player = GetEntityByBase(glowObject.dwBase);

                    if (glowObject.dwBase == NULL || Player == nullptr || Player->is_dormant) {
                        continue;
                    }
                    if (me.team == Player->team) {
                        glow_player(mObj, 0, 0, Friend);
                    }
                    else {
                        glow_player(mObj, Enemy, 0, 0);
                    }
                }
            }
        }
        return EXIT_SUCCESS;
    }
};


int main() 
{
    bool enabled = false;
    HANDLE ESP = NULL;

    virtualesp::start_engine();
    std::cout << "F1 to toggle ESP!" << std::endl;
    while (TRUE)
    {
        if (GetAsyncKeyState(VK_F1) & 1) {
            enabled = !enabled;
            if (enabled) {
                std::cout << "ESP: on" << std::endl;
                ESP = CreateThread(NULL, NULL, &virtualesp::esp_thread, NULL, NULL, NULL);
            }
            else {
                std::cout << "ESP: off" << std::endl;
                TerminateThread(ESP, 0);
                CloseHandle(ESP);
            }
        }
    }
}