param(
    [Parameter(Mandatory = $true)]
    [string]$Executable,
    [string]$OutputDirectory,
    [ValidateRange(0, 11)]
    [int]$PageIndex = -1
)

Add-Type -AssemblyName System.Drawing
Add-Type @'
using System;
using System.Runtime.InteropServices;
public static class NativeUiCapture {
    [StructLayout(LayoutKind.Sequential)]
    public struct Rect { public int Left, Top, Right, Bottom; }
    [DllImport("user32.dll")] public static extern bool GetWindowRect(IntPtr hwnd, out Rect rect);
    [DllImport("user32.dll")] public static extern bool SetForegroundWindow(IntPtr hwnd);
    [DllImport("user32.dll")] public static extern bool SetWindowPos(
        IntPtr hwnd, IntPtr after, int x, int y, int width, int height, uint flags);
    [DllImport("user32.dll")] public static extern bool SetCursorPos(int x, int y);
    [DllImport("user32.dll")] public static extern bool PrintWindow(
        IntPtr hwnd, IntPtr hdc, uint flags);
    [DllImport("user32.dll")] public static extern void mouse_event(
        uint flags, uint dx, uint dy, uint data, UIntPtr extraInfo);
}
'@

if ([string]::IsNullOrWhiteSpace($OutputDirectory)) {
    $OutputDirectory = Join-Path $PSScriptRoot '..\build\ui_screenshots'
}
$OutputDirectory = [System.IO.Path]::GetFullPath($OutputDirectory)
New-Item -ItemType Directory -Path $OutputDirectory -Force | Out-Null
$processArguments = if ($PageIndex -ge 0) {
    @('--page-index', [string]$PageIndex)
} else {
    @()
}
$process = Start-Process -FilePath $Executable -ArgumentList $processArguments -PassThru
try {
    $deadline = [DateTime]::UtcNow.AddSeconds(20)
    do {
        Start-Sleep -Milliseconds 200
        $process.Refresh()
        if ($process.HasExited) {
            throw "Application exited before creating its main window (exit code $($process.ExitCode))."
        }
        $windowValue = if ($null -eq $process.MainWindowHandle) {
            0
        } else {
            $process.MainWindowHandle.ToInt64()
        }
    } while ($windowValue -eq 0 -and [DateTime]::UtcNow -lt $deadline)

    if ($windowValue -eq 0) {
        throw "Application main window was not created."
    }

    [IntPtr]$handle = $process.MainWindowHandle
    [NativeUiCapture]::SetWindowPos($handle, [IntPtr]::Zero, 0, 0, 1440, 900, 0x0040) | Out-Null
    [NativeUiCapture]::SetForegroundWindow($handle) | Out-Null
    Start-Sleep -Seconds 3

    $pageNames = @('system', 'arm', 'camera', 'agv', 'speaker', 'microphone',
        'dexhand', 'biohead', 'hlc', 'test', 'quic', 'diagnostics')
    $pageIndexes = if ($PageIndex -ge 0) { @($PageIndex) } else { 0..($pageNames.Count - 1) }
    foreach ($index in $pageIndexes) {
        [NativeUiCapture]::SetForegroundWindow($handle) | Out-Null
        if ($PageIndex -lt 0) {
            $x = 100
            $y = 164 + 46 * $index
            [NativeUiCapture]::SetCursorPos($x, $y) | Out-Null
            [NativeUiCapture]::mouse_event(0x0002, 0, 0, 0, [UIntPtr]::Zero)
            [NativeUiCapture]::mouse_event(0x0004, 0, 0, 0, [UIntPtr]::Zero)
        }
        Start-Sleep -Milliseconds 1500

        $rect = New-Object NativeUiCapture+Rect
        [NativeUiCapture]::GetWindowRect($handle, [ref]$rect) | Out-Null
        $width = $rect.Right - $rect.Left
        $height = $rect.Bottom - $rect.Top
        $bitmap = New-Object System.Drawing.Bitmap($width, $height)
        $graphics = [System.Drawing.Graphics]::FromImage($bitmap)
        try {
            $deviceContext = $graphics.GetHdc()
            try {
                if (![NativeUiCapture]::PrintWindow($handle, $deviceContext, 2)) {
                    throw "Failed to render the application window."
                }
            } finally {
                $graphics.ReleaseHdc($deviceContext)
            }
            $path = Join-Path $OutputDirectory ($pageNames[$index] + '.png')
            $bitmap.Save($path, [System.Drawing.Imaging.ImageFormat]::Png)
        } finally {
            $graphics.Dispose()
            $bitmap.Dispose()
        }
    }
} finally {
    if (!$process.HasExited) {
        $process.CloseMainWindow() | Out-Null
        if (!$process.WaitForExit(5000)) {
            $process.Kill()
        }
    }
}