using System;
using System.Runtime.InteropServices;
using System.Text;

namespace FastSeekWpf.NativeInterop;

internal static class Win32Api
{
    // Messages
    public const uint WM_USER = 0x0400;
    public const uint WM_HOTKEY = 0x0312;
    public const uint WM_ACTIVATE = 0x0006;
    public const uint WA_INACTIVE = 0;

    // Window styles
    public const uint WS_POPUP = 0x80000000;
    public const uint WS_VISIBLE = 0x10000000;
    public const uint WS_EX_TOOLWINDOW = 0x00000080;
    public const uint WS_EX_NOACTIVATE = 0x08000000;
    public const uint WS_EX_TOPMOST = 0x00000008;

    // PeekMessage
    public const uint PM_REMOVE = 0x0001;

    // File access
    public const uint GENERIC_READ = 0x80000000;
    public const uint FILE_SHARE_READ = 0x00000001;
    public const uint FILE_SHARE_WRITE = 0x00000002;
    public const uint FILE_SHARE_DELETE = 0x00000004;
    public const uint OPEN_EXISTING = 3;
    public const uint FILE_FLAG_BACKUP_SEMANTICS = 0x02000000;
    public const uint FILE_FLAG_SEQUENTIAL_SCAN = 0x08000000;

    // ── IOCTL codes ──
    // From Windows SDK winioctl.h. Verified against windows-rs crate.
    public const uint FSCTL_ENUM_USN_DATA = 0x000900B3;
    public const uint FSCTL_QUERY_USN_JOURNAL = 0x000900F4;
    public const uint FSCTL_READ_USN_JOURNAL = 0x000900BB;

    // USN reasons
    public const uint USN_REASON_FILE_CREATE = 0x00000100;
    public const uint USN_REASON_FILE_DELETE = 0x00000200;
    public const uint USN_REASON_RENAME_OLD_NAME = 0x00001000;
    public const uint USN_REASON_RENAME_NEW_NAME = 0x00002000;

    // Win32 error codes (raw, NOT HRESULT)
    // Marshal.GetLastWin32Error() returns these raw codes.
    // Rust windows-rs wraps them as HRESULT (0x8007XXXX).
    public const int ERROR_HANDLE_EOF = 38;               // Raw: 0x26
    public const int ERROR_INSUFFICIENT_BUFFER = 122;    // Raw: 0x7A
    public const int ERROR_JOURNAL_NOT_ACTIVE = 1179;    // Raw: 0x49B

    // DWM
    public const int DWMWA_WINDOW_CORNER_PREFERENCE = 33;
    public const int DWMWA_USE_IMMERSIVE_DARK_MODE = 20;
    public const int DWMWCP_ROUND = 2;

    // Kernel32
    [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
    public static extern IntPtr CreateFileW(
        string lpFileName,
        uint dwDesiredAccess,
        uint dwShareMode,
        IntPtr lpSecurityAttributes,
        uint dwCreationDisposition,
        uint dwFlagsAndAttributes,
        IntPtr hTemplateFile);

    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern bool ReadFile(
        IntPtr hFile,
        byte[] lpBuffer,
        uint nNumberOfBytesToRead,
        out uint lpNumberOfBytesRead,
        IntPtr lpOverlapped);

    // Unsafe overload: read into a byte[] at a given offset — matches Rust ReadFile into &mut buffer[leftover..]
    public static unsafe bool ReadFile(
        IntPtr hFile,
        byte[] lpBuffer,
        int offset,
        uint nNumberOfBytesToRead,
        out uint lpNumberOfBytesRead,
        IntPtr lpOverlapped)
    {
        fixed (byte* p = &lpBuffer[offset])
        {
            return ReadFilePointer(hFile, p, nNumberOfBytesToRead, out lpNumberOfBytesRead, lpOverlapped);
        }
    }

    [DllImport("kernel32.dll", SetLastError = true, EntryPoint = "ReadFile")]
    private static extern unsafe bool ReadFilePointer(
        IntPtr hFile,
        byte* lpBuffer,
        uint nNumberOfBytesToRead,
        out uint lpNumberOfBytesRead,
        IntPtr lpOverlapped);

    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern bool SetFilePointerEx(
        IntPtr hFile,
        long liDistanceToMove,
        out long lpNewFilePointer,
        uint dwMoveMethod);

    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern bool DeviceIoControl(
        IntPtr hDevice,
        uint dwIoControlCode,
        IntPtr lpInBuffer,
        uint nInBufferSize,
        IntPtr lpOutBuffer,
        uint nOutBufferSize,
        out uint lpBytesReturned,
        IntPtr lpOverlapped);

    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern bool CloseHandle(IntPtr hObject);

    [DllImport("kernel32.dll", CharSet = CharSet.Unicode)]
    public static extern uint GetLogicalDriveStringsW(uint nBufferLength, [Out] char[] lpBuffer);

    [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    public static extern bool GetVolumeInformationW(
        string lpRootPathName,
        StringBuilder? lpVolumeNameBuffer,
        uint nVolumeNameSize,
        out uint lpVolumeSerialNumber,
        out uint lpMaximumComponentLength,
        out uint lpFileSystemFlags,
        StringBuilder lpFileSystemNameBuffer,
        uint nFileSystemNameSize);

    // User32
    [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
    public static extern IntPtr FindWindowW(string? lpClassName, string? lpWindowName);

    [DllImport("user32.dll")]
    public static extern bool PostMessageW(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);

    [DllImport("user32.dll", SetLastError = true)]
    public static extern bool RegisterHotKey(IntPtr hWnd, int id, uint fsModifiers, uint vk);

    [DllImport("user32.dll", SetLastError = true)]
    public static extern bool UnregisterHotKey(IntPtr hWnd, int id);

    [DllImport("user32.dll")]
    public static extern int GetMessageW(out MSG lpMsg, IntPtr hWnd, uint wMsgFilterMin, uint wMsgFilterMax);

    [DllImport("user32.dll")]
    public static extern bool PeekMessageW(out MSG lpMsg, IntPtr hWnd, uint wMsgFilterMin, uint wMsgFilterMax, uint wRemoveMsg);

    [DllImport("user32.dll")]
    public static extern bool TranslateMessage(ref MSG lpMsg);

    [DllImport("user32.dll")]
    public static extern IntPtr DispatchMessageW(ref MSG lpMsg);

    [DllImport("user32.dll")]
    public static extern int GetSystemMetrics(int nIndex);
    public const int SM_CXSCREEN = 0;
    public const int SM_CYSCREEN = 1;

    [DllImport("user32.dll")]
    public static extern bool SetForegroundWindow(IntPtr hWnd);

    [DllImport("user32.dll")]
    public static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
    public const int SW_HIDE = 0;
    public const int SW_SHOW = 5;

    // Shell32
    [DllImport("shell32.dll", CharSet = CharSet.Unicode)]
    public static extern IntPtr ShellExecuteW(
        IntPtr hwnd,
        string lpOperation,
        string lpFile,
        string? lpParameters,
        string? lpDirectory,
        int nShowCmd);

    // Dwmapi
    [DllImport("dwmapi.dll")]
    public static extern int DwmSetWindowAttribute(IntPtr hwnd, int attr, ref int attrValue, int attrSize);

    // Structs
    [StructLayout(LayoutKind.Sequential)]
    public struct MSG
    {
        public IntPtr hwnd;
        public uint message;
        public IntPtr wParam;
        public IntPtr lParam;
        public uint time;
        public POINT pt;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct POINT
    {
        public int x;
        public int y;
    }
}