#include <std_include.hpp>
#include "loader/component_loader.hpp"
#include "scheduler.hpp"

#include "steam/steam.hpp"
#include <utils/hook.hpp>

#define ProcessDebugPort 7
#define ProcessDebugObjectHandle 30 // WinXP source says 31?
#define ProcessDebugFlags 31 // WinXP source says 32?

namespace arxan
{
	namespace
	{
		const auto pseudo_steam_id = 0x1337;
		const auto pseudo_steam_handle = reinterpret_cast<HANDLE>(reinterpret_cast<uint64_t>(INVALID_HANDLE_VALUE) -
			pseudo_steam_id);

		utils::hook::detour nt_close_hook;
		utils::hook::detour nt_query_system_information_hook;
		utils::hook::detour nt_query_information_process_hook;
		utils::hook::detour create_mutex_ex_a_hook;
		utils::hook::detour open_process_hook;

		HANDLE process_id_to_handle(const DWORD pid)
		{
			return reinterpret_cast<HANDLE>(static_cast<DWORD64>(pid));
		}

		void check_steam_install()
		{
			if (!*steam::SteamAPI_GetSteamInstallPath())
			{
				MessageBoxA(nullptr, "Steam must be installed for the game to run. Please install steam!", "Error",
				            MB_ICONERROR);
				TerminateProcess(GetCurrentProcess(), 1);
			}
		}

		HANDLE WINAPI open_process_stub(const DWORD access, const BOOL inherit, const DWORD pid)
		{
			if (pid == pseudo_steam_id)
			{
				return pseudo_steam_handle;
			}

			return open_process_hook.invoke<HANDLE>(access, inherit, pid);
		}

		HANDLE create_mutex_ex_a_stub(const LPSECURITY_ATTRIBUTES attributes, const LPCSTR name, const DWORD flags,
		                              const DWORD access)
		{
			if (name == "$ IDA trusted_idbs"s || name == "$ IDA registry mutex $"s)
			{
				return nullptr;
			}

			return create_mutex_ex_a_hook.invoke<HANDLE>(attributes, name, flags, access);
		}

		bool remove_evil_keywords_from_string(const UNICODE_STRING& string)
		{
			static const std::wstring evil_keywords[] =
			{
				L"IDA",
				L"ida",
				L"HxD",
				L"cheatengine",
				L"Cheat Engine",
			};

			if (!string.Buffer || !string.Length)
			{
				return false;
			}

			std::wstring_view path(string.Buffer, string.Length / sizeof(string.Buffer[0]));

			bool modified = false;
			for (const auto& keyword : evil_keywords)
			{
				while (true)
				{
					const auto pos = path.find(keyword);
					if (pos == std::wstring::npos)
					{
						break;
					}

					modified = true;

					for (size_t i = 0; i < keyword.size(); ++i)
					{
						string.Buffer[pos + i] = L'a';
					}
				}
			}

			return modified;
		}

		bool remove_evil_keywords_from_string(wchar_t* str, const size_t length)
		{
			UNICODE_STRING unicode_string{};
			unicode_string.Buffer = str;
			unicode_string.Length = static_cast<uint16_t>(length);
			unicode_string.MaximumLength = unicode_string.Length;

			return remove_evil_keywords_from_string(unicode_string);
		}

		bool remove_evil_keywords_from_string(char* str, const size_t length)
		{
			std::string_view str_view(str, length);
			std::wstring wstr(str_view.begin(), str_view.end());

			if (!remove_evil_keywords_from_string(&wstr[0], wstr.size()))
			{
				return false;
			}

			const std::string regular_str(wstr.begin(), wstr.end());
			memcpy(str, regular_str.data(), length);

			return true;
		}


		int WINAPI get_window_text_a_stub(const HWND wnd, const LPSTR str, const int max_count)
		{
			std::wstring wstr{};
			wstr.resize(max_count);

			const auto res = GetWindowTextW(wnd, &wstr[0], max_count);
			if (res)
			{
				remove_evil_keywords_from_string(wstr.data(), res);

				const std::string regular_str(wstr.begin(), wstr.end());
				memset(str, 0, max_count);
				memcpy(str, regular_str.data(), res);
			}

			return res;
		}

		NTSTATUS NTAPI nt_query_system_information_stub(const SYSTEM_INFORMATION_CLASS system_information_class,
		                                                const PVOID system_information,
		                                                const ULONG system_information_length,
		                                                const PULONG return_length)
		{
			const auto status = nt_query_system_information_hook.invoke<NTSTATUS>(
				system_information_class, system_information, system_information_length, return_length);

			if (NT_SUCCESS(status))
			{
				if (system_information_class == SystemProcessInformation)
				{
					bool injected_steam = false;
					auto addr = static_cast<uint8_t*>(system_information);
					while (true)
					{
						const auto info = reinterpret_cast<SYSTEM_PROCESS_INFORMATION*>(addr);
						remove_evil_keywords_from_string(info->ImageName);

						static const auto our_pid = process_id_to_handle(GetCurrentProcessId());

						if (!injected_steam && info->UniqueProcessId != our_pid)
						{
							static wchar_t steam_path[] = L"steam.exe";

							info->UniqueProcessId = process_id_to_handle(pseudo_steam_id);
							info->ImageName.Buffer = steam_path;
							info->ImageName.Length = static_cast<uint16_t>(wcslen(steam_path) * 2u);
							info->ImageName.MaximumLength = info->ImageName.Length;

							injected_steam = true;
						}

						if (!info->NextEntryOffset)
						{
							break;
						}

						addr = addr + info->NextEntryOffset;
					}
				}
			}

			return status;
		}

		bool handle_pseudo_steam_process(const HANDLE handle, const PROCESSINFOCLASS info_class,
		                                 const PVOID info,
		                                 const ULONG info_length, const PULONG ret_length, NTSTATUS* status)
		{
			if (handle != pseudo_steam_handle || info_class != 43)
			{
				return false;
			}

			const auto steam_folder = steam::SteamAPI_GetSteamInstallPath();
			const auto steam_path = steam_folder + "\\steam.exe"s;
			const std::wstring wide_path(steam_path.begin(), steam_path.end());

			const auto required_size = static_cast<ULONG>((wide_path.size() + 1u) * 2u + sizeof(UNICODE_STRING));

			if (ret_length)
			{
				*ret_length = required_size;
			}

			if (info_length < required_size)
			{
				*status = static_cast<LONG>(0xC0000004);
				return true;
			}

			memset(info, 0, info_length);

			auto& str = *static_cast<UNICODE_STRING*>(info);
			str.Buffer = reinterpret_cast<wchar_t*>(&str + 1);
			str.Length = static_cast<uint16_t>(wide_path.size() * 2u);
			str.MaximumLength = str.Length;

			memcpy(str.Buffer, wide_path.data(), str.Length);

			*status = 0;
			return true;
		}

		NTSTATUS WINAPI nt_query_information_process_stub(const HANDLE handle, const PROCESSINFOCLASS info_class,
		                                                  const PVOID info,
		                                                  const ULONG info_length, const PULONG ret_length)
		{
			NTSTATUS status{0};
			if (handle_pseudo_steam_process(handle, info_class, info, info_length, ret_length, &status))
			{
				return status;
			}

			status = nt_query_information_process_hook.invoke<NTSTATUS>(handle, info_class, info, info_length,
			                                                            ret_length);

			if (NT_SUCCESS(status))
			{
				if (info_class == ProcessBasicInformation)
				{
					static_cast<PPROCESS_BASIC_INFORMATION>(info)->Reserved3 = process_id_to_handle(pseudo_steam_id);
				}
				else if (info_class == ProcessDebugObjectHandle)
				{
					*static_cast<HANDLE*>(info) = nullptr;
					return static_cast<LONG>(0xC0000353);
				}
				else if (info_class == ProcessImageFileName || info_class == 43 /* ? */)
				{
					remove_evil_keywords_from_string(*static_cast<UNICODE_STRING*>(info));
				}
				else if (info_class == ProcessDebugPort)
				{
					*static_cast<HANDLE*>(info) = nullptr;
				}
				else if (info_class == ProcessDebugFlags)
				{
					*static_cast<ULONG*>(info) = 1;
				}
			}

			return status;
		}

		NTSTATUS NTAPI nt_close_stub(const HANDLE handle)
		{
			if (handle == pseudo_steam_handle)
			{
				return 0;
			}

			char info[16];
			if (NtQueryObject(handle, OBJECT_INFORMATION_CLASS(4), &info, 2, nullptr) >= 0 && size_t(handle) != 0x12345)
			{
				return nt_close_hook.invoke<NTSTATUS>(handle);
			}

			return STATUS_INVALID_HANDLE;
		}

		LONG WINAPI exception_filter(const LPEXCEPTION_POINTERS info)
		{
			if (info->ExceptionRecord->ExceptionCode == STATUS_INVALID_HANDLE)
			{
				return EXCEPTION_CONTINUE_EXECUTION;
			}

			if (info->ExceptionRecord->ExceptionCode == STATUS_ACCESS_VIOLATION)
			{
				//MessageBoxA(0, 0, "AV", 0);
			}

			return EXCEPTION_CONTINUE_SEARCH;
		}

		void hide_being_debugged()
		{
			auto* const peb = reinterpret_cast<PPEB>(__readgsqword(0x60));
			peb->BeingDebugged = false;
			*reinterpret_cast<PDWORD>(LPSTR(peb) + 0xBC) &= ~0x70;
		}

		void restore_debug_functions()
		{
			static const char* functions[] = {
				"DbgBreakPoint",
				"DbgUserBreakPoint",
				"DbgUiConnectToDbg",
				"DbgUiContinue",
				"DbgUiConvertStateChangeStructure",
				"DbgUiDebugActiveProcess",
				"DbgUiGetThreadDebugObject",
				"DbgUiIssueRemoteBreakin",
				"DbgUiRemoteBreakin",
				"DbgUiSetThreadDebugObject",
				"DbgUiStopDebugging",
				"DbgUiWaitStateChange",
				"DbgPrintReturnControlC",
				"DbgPrompt",
			};

			using buffer = uint8_t[15];
			static buffer buffers[ARRAYSIZE(functions)] = {};
			static bool loaded = false;

			const utils::nt::library ntdll("ntdll.dll");

			for (auto i = 0u; i < ARRAYSIZE(functions); ++i)
			{
				const auto func = ntdll.get_proc<void*>(functions[i]);
				if (!loaded)
				{
					memcpy(buffers[i], func, sizeof(buffer));
				}
				else
				{
					utils::hook::copy(func, buffers[i], sizeof(buffer));
				}
			}

			loaded = true;
		}

		const char* get_command_line_a_stub()
		{
			static auto cmd = []
			{
				std::string cmd_line = GetCommandLineA();
				if (!strstr(cmd_line.data(), "fs_game"))
				{
					cmd_line += " +set fs_game \"T7x\"";
				}

				return cmd_line;
			}();

			return cmd.data();
		}
	}

	class component final : public component_interface
	{
	public:
		void post_load() override
		{
			check_steam_install();

			hide_being_debugged();
			scheduler::loop(hide_being_debugged, scheduler::pipeline::async);

			//restore_debug_functions();

			create_mutex_ex_a_hook.create(CreateMutexExA, create_mutex_ex_a_stub);


			const utils::nt::library ntdll("ntdll.dll");
			nt_close_hook.create(ntdll.get_proc<void*>("NtClose"), nt_close_stub);

			const auto nt_query_information_process = ntdll.get_proc<void*>("NtQueryInformationProcess");
			nt_query_information_process_hook.create(nt_query_information_process,
			                                         nt_query_information_process_stub);

			const auto nt_query_system_information = ntdll.get_proc<void*>("NtQuerySystemInformation");
			nt_query_system_information_hook.create(nt_query_system_information, nt_query_system_information_stub);
			nt_query_system_information_hook.move();

			open_process_hook.create(OpenProcess, open_process_stub);

			utils::hook::copy(this->window_text_buffer_, GetWindowTextA, sizeof(this->window_text_buffer_));
			utils::hook::jump(GetWindowTextA, get_window_text_a_stub, true, true);
			utils::hook::move_hook(GetWindowTextA);

			AddVectoredExceptionHandler(1, exception_filter);

			// TODO: Remove as soon as real hooking works
			auto* cmd_func = utils::nt::library{}.get_iat_entry("kernel32.dll", "GetCommandLineA");
			if (cmd_func)
			{
				utils::hook::set(cmd_func, get_command_line_a_stub);
			}
		}

		void pre_destroy() override
		{
			utils::hook::copy(GetWindowTextA, this->window_text_buffer_, sizeof(this->window_text_buffer_));
			nt_query_system_information_hook.clear();
			nt_query_information_process_hook.clear();
			nt_close_hook.clear();
			create_mutex_ex_a_hook.clear();
			open_process_hook.clear();
		}

	private:
		uint8_t window_text_buffer_[15]{};
	};
}

REGISTER_COMPONENT(arxan::component)