#if UNITY_STANDALONE_WIN || UNITY_EDITOR_WIN
using System;
using System.ComponentModel;
using System.Runtime.InteropServices;
// ReSharper disable FieldCanBeMadeReadOnly.Local
// ReSharper disable InconsistentNaming
// ReSharper disable UnusedMember.Local
// ReSharper disable MemberCanBePrivate.Local

namespace Lavender.Systems
{
    public static class StartExternalProcess
    {
        [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool CreateProcessW(
            string lpApplicationName,
            [In] string lpCommandLine,
            IntPtr procSecAttrs,
            IntPtr threadSecAttrs,
            bool bInheritHandles,
            ProcessCreationFlags dwCreationFlags,
            IntPtr lpEnvironment,
            string lpCurrentDirectory,
            ref STARTUPINFO lpStartupInfo,
            ref PROCESS_INFORMATION lpProcessInformation
        );

        [DllImport("kernel32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool CloseHandle(IntPtr hObject);

        [DllImport("kernel32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool TerminateProcess(IntPtr processHandle, uint exitCode);

        [DllImport("kernel32.dll", SetLastError = true)]
        private static extern IntPtr OpenProcess(ProcessAccessRights access, bool inherit, uint processId);

        [Flags]
        private enum ProcessAccessRights : uint
        {
            PROCESS_CREATE_PROCESS = 0x0080, //  Required to create a process.
            PROCESS_CREATE_THREAD = 0x0002, //  Required to create a thread.
            PROCESS_DUP_HANDLE = 0x0040, // Required to duplicate a handle using DuplicateHandle.
            PROCESS_QUERY_INFORMATION = 0x0400, //  Required to retrieve certain information about a process, such as its token, exit code, and priority class (see OpenProcessToken, GetExitCodeProcess, GetPriorityClass, and IsProcessInJob).
            PROCESS_QUERY_LIMITED_INFORMATION = 0x1000, //  Required to retrieve certain information about a process (see QueryFullProcessImageName). A handle that has the PROCESS_QUERY_INFORMATION access right is automatically granted PROCESS_QUERY_LIMITED_INFORMATION. Windows Server 2003 and Windows XP/2000:  This access right is not supported.
            PROCESS_SET_INFORMATION = 0x0200, //    Required to set certain information about a process, such as its priority class (see SetPriorityClass).
            PROCESS_SET_QUOTA = 0x0100, //  Required to set memory limits using SetProcessWorkingSetSize.
            PROCESS_SUSPEND_RESUME = 0x0800, // Required to suspend or resume a process.
            PROCESS_TERMINATE = 0x0001, //  Required to terminate a process using TerminateProcess.
            PROCESS_VM_OPERATION = 0x0008, //   Required to perform an operation on the address space of a process (see VirtualProtectEx and WriteProcessMemory).
            PROCESS_VM_READ = 0x0010, //    Required to read memory in a process using ReadProcessMemory.
            PROCESS_VM_WRITE = 0x0020, //   Required to write to memory in a process using WriteProcessMemory.
            DELETE = 0x00010000, // Required to delete the object.
            READ_CONTROL = 0x00020000, //   Required to read information in the security descriptor for the object, not including the information in the SACL. To read or write the SACL, you must request the ACCESS_SYSTEM_SECURITY access right. For more information, see SACL Access Right.
            SYNCHRONIZE = 0x00100000, //    The right to use the object for synchronization. This enables a thread to wait until the object is in the signaled state.
            WRITE_DAC = 0x00040000, //  Required to modify the DACL in the security descriptor for the object.
            WRITE_OWNER = 0x00080000, //    Required to change the owner in the security descriptor for the object.
            STANDARD_RIGHTS_REQUIRED = 0x000f0000,
            PROCESS_ALL_ACCESS = STANDARD_RIGHTS_REQUIRED | SYNCHRONIZE | 0xFFF //    All possible access rights for a process object.
        }

        [StructLayout(LayoutKind.Sequential)]
        private struct PROCESS_INFORMATION
        {
            internal IntPtr hProcess;
            internal IntPtr hThread;
            internal uint dwProcessId;
            internal uint dwThreadId;
        }

        [StructLayout(LayoutKind.Sequential)]
        private struct STARTUPINFO
        {
            internal uint cb;
            internal IntPtr lpReserved;
            internal IntPtr lpDesktop;
            internal IntPtr lpTitle;
            internal uint dwX;
            internal uint dwY;
            internal uint dwXSize;
            internal uint dwYSize;
            internal uint dwXCountChars;
            internal uint dwYCountChars;
            internal uint dwFillAttribute;
            internal uint dwFlags;
            internal ushort wShowWindow;
            internal ushort cbReserved2;
            internal IntPtr lpReserved2;
            internal IntPtr hStdInput;
            internal IntPtr hStdOutput;
            internal IntPtr hStdError;
        }

        [Flags]
        private enum ProcessCreationFlags : uint
        {
            NONE = 0,
            CREATE_BREAKAWAY_FROM_JOB = 0x01000000,
            CREATE_DEFAULT_ERROR_MODE = 0x04000000,
            CREATE_NEW_CONSOLE = 0x00000010,
            CREATE_NEW_PROCESS_GROUP = 0x00000200,
            CREATE_NO_WINDOW = 0x08000000,
            CREATE_PROTECTED_PROCESS = 0x00040000,
            CREATE_PRESERVE_CODE_AUTHZ_LEVEL = 0x02000000,
            CREATE_SECURE_PROCESS = 0x00400000,
            CREATE_SEPARATE_WOW_VDM = 0x00000800,
            CREATE_SHARED_WOW_VDM = 0x00001000,
            CREATE_SUSPENDED = 0x00000004,
            CREATE_UNICODE_ENVIRONMENT = 0x00000400,
            DEBUG_ONLY_THIS_PROCESS = 0x00000002,
            DEBUG_PROCESS = 0x00000001,
            DETACHED_PROCESS = 0x00000008,
            EXTENDED_STARTUPINFO_PRESENT = 0x00080000,
            INHERIT_PARENT_AFFINITY = 0x00010000
        }

        public static uint Start(string path, string dir = null, bool hidden = false)
        {
            ProcessCreationFlags flags = hidden ? ProcessCreationFlags.CREATE_NO_WINDOW : ProcessCreationFlags.NONE;
            STARTUPINFO startupinfo = new STARTUPINFO
            {
                cb = (uint)Marshal.SizeOf<STARTUPINFO>()
            };
            PROCESS_INFORMATION processinfo = new PROCESS_INFORMATION();
            if (!CreateProcessW(null, path, IntPtr.Zero, IntPtr.Zero, false, flags, IntPtr.Zero, dir, ref startupinfo, ref processinfo))
            {
                throw new Win32Exception();
            }

            return processinfo.dwProcessId;
        }

        public static int KillProcess(uint pid)
        {
            IntPtr handle = OpenProcess(ProcessAccessRights.PROCESS_ALL_ACCESS, false, pid);

            if (handle == IntPtr.Zero)
            {
                return -1;
            }
            if (!TerminateProcess(handle, 0))
            {
                throw new Win32Exception();
            }
            if (!CloseHandle(handle))
            {
                throw new Win32Exception();
            }

            return 0;
        }
    }
}
#endif