# SVG → multi-size .ico mittels WPF (Bordmittel, kein extra Tool nötig)
# Generiert logo.ico mit 16, 32, 48, 64, 128, 256 Pixeln

Add-Type -AssemblyName PresentationCore, PresentationFramework, WindowsBase

$ScriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
$IcoPath = Join-Path $ScriptDir 'logo.ico'

function New-LogoBitmap {
    param([int]$Size)

    $dv = [System.Windows.Media.DrawingVisual]::new()
    $dc = $dv.RenderOpen()
    $scale = $Size / 256.0

    # Hintergrund
    $bgRect = [System.Windows.Rect]::new(8 * $scale, 8 * $scale, 240 * $scale, 240 * $scale)
    $bgBrush = [System.Windows.Media.SolidColorBrush]::new(
        [System.Windows.Media.Color]::FromRgb(0x1A, 0x1A, 0x1A))
    $dc.DrawRoundedRectangle($bgBrush, $null, $bgRect, 40 * $scale, 40 * $scale)

    # Blauer Gradient
    $gradStart = [System.Windows.Media.Color]::FromRgb(0x00, 0x78, 0xD4)
    $gradEnd   = [System.Windows.Media.Color]::FromRgb(0x00, 0x5A, 0x9E)
    $grad = [System.Windows.Media.LinearGradientBrush]::new($gradStart, $gradEnd, 90)
    $grad.Freeze()

    # Bildschirm-Rahmen
    $screenRect = [System.Windows.Rect]::new(40 * $scale, 56 * $scale, 176 * $scale, 120 * $scale)
    $screenPen = [System.Windows.Media.Pen]::new($grad, 6 * $scale)
    $dc.DrawRoundedRectangle($null, $screenPen, $screenRect, 10 * $scale, 10 * $scale)

    # Streaming-Wellen
    $wavePen = [System.Windows.Media.Pen]::new($grad, 5 * $scale)
    $wavePen.StartLineCap = 'Round'
    $wavePen.EndLineCap = 'Round'

    foreach ($wave in @(@(70, 140, 90, 110, 120, 110), @(70, 140, 100, 90, 145, 90), @(70, 140, 110, 70, 170, 70))) {
        $geom = [System.Windows.Media.StreamGeometry]::new()
        $ctx = $geom.Open()
        $ctx.BeginFigure([System.Windows.Point]::new($wave[0] * $scale, $wave[1] * $scale), $false, $false)
        $ctx.QuadraticBezierTo(
            [System.Windows.Point]::new($wave[2] * $scale, $wave[3] * $scale),
            [System.Windows.Point]::new($wave[4] * $scale, $wave[5] * $scale), $true, $false)
        $ctx.Close()
        $geom.Freeze()
        $dc.DrawGeometry($null, $wavePen, $geom)
    }

    # Punkt am Ursprung
    $dc.DrawEllipse($grad, $null,
        [System.Windows.Point]::new(70 * $scale, 140 * $scale),
        6 * $scale, 6 * $scale)

    # Standfuß
    $foot1 = [System.Windows.Rect]::new(100 * $scale, 184 * $scale, 56 * $scale, 8 * $scale)
    $foot2 = [System.Windows.Rect]::new( 80 * $scale, 196 * $scale, 96 * $scale, 8 * $scale)
    $dc.DrawRoundedRectangle($grad, $null, $foot1, 2 * $scale, 2 * $scale)
    $dc.DrawRoundedRectangle($grad, $null, $foot2, 3 * $scale, 3 * $scale)

    $dc.Close()

    $rtb = [System.Windows.Media.Imaging.RenderTargetBitmap]::new(
        $Size, $Size, 96, 96, [System.Windows.Media.PixelFormats]::Pbgra32)
    $rtb.Render($dv)
    return $rtb
}

function Get-PngBytes {
    param($bitmap)
    $encoder = [System.Windows.Media.Imaging.PngBitmapEncoder]::new()
    $encoder.Frames.Add([System.Windows.Media.Imaging.BitmapFrame]::Create($bitmap))
    $ms = [System.IO.MemoryStream]::new()
    $encoder.Save($ms)
    $bytes = $ms.ToArray()
    $ms.Dispose()
    return ,$bytes
}

# Generierung mit ArrayList damit Wrapping vorhersehbar ist
$sizes = @(16, 32, 48, 64, 128, 256)
$pngList = New-Object System.Collections.ArrayList
foreach ($size in $sizes) {
    Write-Host "  Rendere ${size}x${size}..."
    $bmp = New-LogoBitmap -Size $size
    $bytes = Get-PngBytes $bmp
    [void]$pngList.Add($bytes)
    Write-Host "    PNG: $($bytes.Length) bytes"
}

# ICO bauen
$out = [System.IO.MemoryStream]::new()
$bw = [System.IO.BinaryWriter]::new($out)
$bw.Write([UInt16]0)                   # reserved
$bw.Write([UInt16]1)                   # type = ICO
$bw.Write([UInt16]$pngList.Count)      # count

$dataOffset = 6 + ($pngList.Count * 16)
for ($i = 0; $i -lt $pngList.Count; $i++) {
    $size = $sizes[$i]
    $w = if ($size -eq 256) { 0 } else { $size }
    $h = if ($size -eq 256) { 0 } else { $size }
    $len = $pngList[$i].Length
    $bw.Write([byte]$w)
    $bw.Write([byte]$h)
    $bw.Write([byte]0)
    $bw.Write([byte]0)
    $bw.Write([UInt16]1)
    $bw.Write([UInt16]32)
    $bw.Write([UInt32]$len)
    $bw.Write([UInt32]$dataOffset)
    $dataOffset += $len
}
for ($i = 0; $i -lt $pngList.Count; $i++) {
    $bytes = $pngList[$i]
    $bw.Write($bytes, 0, $bytes.Length)
}
$bw.Flush()
[System.IO.File]::WriteAllBytes($IcoPath, $out.ToArray())
$bw.Close()
$out.Dispose()

$icoSize = (Get-Item $IcoPath).Length
Write-Host "`nFertig: $IcoPath ($icoSize Bytes, $($pngList.Count) Größen)"