Gotify client for Windows Notifications

config.ps1

$domain = "p.domain.com"
$token = "AAAAAAAA"
$useHeaders = $false

gotify.ps1

. .\config.ps1
$script:sentNotifications = @()

Function Log($text){
    Out-File -Append -encoding UTF8 -FilePath .\log.txt -InputObject $((get-date).ToString('T')+": "+$text.Trim().Replace("[char]39","'"))
}

Function Output($text){
    $jsonData = convertfrom-json $text
    $msgid = $jsonData.id
    if($script:sentNotifications.Contains($msgid)){
        Log("Notification already sent, skipping")
        Return
    }
    $script:sentNotifications += $msgid

    $jsonData.message = $jsonData.message.Replace("'","[char]39")
    $jsonData.title = $jsonData.title.Replace("'","[char]39")

    if($jsonData.message.Contains("base64")){
        Log("Converting base64 encoded image")
        $messageText = ($jsonData.message -split [regex]::Escape("![]("))[0].Trim()
        $imageString = ($jsonData.message -split [regex]::Escape("![]("))[1].Split(")")[0]
        $encodedImage = $imageString.Split(',')[1]
        $decoded = [System.Convert]::FromBase64CharArray($encodedImage, 0, $encodedImage.Length)
        $cacheImage = ".\cache\"+$msgid+".jpg"
        Set-Content -Path $cacheImage -Value $decoded -AsByteStream
        $jsonData.message = $messageText + "  ![](" + $cacheImage + ")"
    }
    $text = ConvertTo-Json $jsonData -Compress -Depth 3
    Log($text)
    $cmd = "'$text' | .\toast.ps1"
    $encodedcmd = [Convert]::ToBase64String([Text.Encoding]::Unicode.GetBytes($cmd))
    $process = start-process pwsh -ArgumentList "-noexit -encodedcommand $encodedcmd" -PassThru -NoNewWindow
}

Function Init-Websocket(){
    $recv_queue = New-Object 'System.Collections.Concurrent.ConcurrentQueue[String]'

    $ws = New-Object Net.WebSockets.ClientWebSocket
    $cts = New-Object Threading.CancellationTokenSource
    $ct = New-Object Threading.CancellationToken($false)

    Log("Connecting...")
    $connectTask = $ws.ConnectAsync("wss://$domain/stream?token=$token", $cts.Token)
    do { Sleep(1) }
    until ($connectTask.IsCompleted)
    Log("Connected!")

    $recv_job = {
        param($ws, $recv_queue)

        $buffer = [Net.WebSockets.WebSocket]::CreateClientBuffer(1024,1024)
        $ct = [Threading.CancellationToken]::new($false)
        $taskResult = $null

        while ($ws.State -eq [Net.WebSockets.WebSocketState]::Open) {
            $jsonResult = ""
            do {
                $taskResult = $ws.ReceiveAsync($buffer, $ct)
                while (-not $taskResult.IsCompleted -and $ws.State -eq [Net.WebSockets.WebSocketState]::Open) {
                    [Threading.Thread]::Sleep(10)
                }

                $jsonResult += [Text.Encoding]::UTF8.GetString($buffer, 0, $taskResult.Result.Count)
            } until (
                $ws.State -ne [Net.WebSockets.WebSocketState]::Open -or $taskResult.Result.EndOfMessage
            )

            if (-not [string]::IsNullOrEmpty($jsonResult)) {
                $recv_queue.Enqueue($jsonResult)
            }
       }
     }

    Log("Starting recv runspace")
    $recv_runspace = [PowerShell]::Create()
    $recv_runspace.AddScript($recv_job).
        AddParameter("ws", $ws).
        AddParameter("recv_queue", $recv_queue).BeginInvoke() | Out-Null

    try {
        do {
            Start-Sleep -Milli 500
            $msg = $null
            while ($recv_queue.TryDequeue([ref] $msg)) {
                if ($msg.StartsWith('{')){
                    Output($msg)
                }else{
                    Log("Response: "+$msg)
                }
            }
        } until ($ws.State -ne [Net.WebSockets.WebSocketState]::Open)
    }
    finally {
        Log("Closing WS connection")
        $closetask = $ws.CloseAsync(
            [System.Net.WebSockets.WebSocketCloseStatus]::Empty,
            "",
            $ct
        )

        do { Sleep(1) }
        until ($closetask.IsCompleted)
        $ws.Dispose()

        Log("Stopping runspace")
        $recv_runspace.Stop()
        $recv_runspace.Dispose()
        
        Log("Reconnecting")
        Poll-Server
        Init-Websocket        
    }
}

Function Poll-Server(){
    Log("Polling for missed notifications")
    Invoke-WebRequest "https://$domain/message?token=$token" -SessionVariable session -ContentType "application/json; charset=utf-8" | %{ convertfrom-json $_.Content } | where-object {$_.messages.length -gt 0} | select -expand messages | %{ Output(ConvertTo-JSON -Compress -Depth 3 $_) }
}

if(Test-Path -Path ".\log.txt" -PathType Leaf){
    Move-Item -Path ".\log.txt" -Destination ".\log.txt.old" -Force
}
if(!(Test-Path -Path ".\cache\" -PathType Leaf)){
    New-Item -Path ".\cache\" -ItemType Directory -Force | Out-Null
}

Poll-Server
Init-Websocket

toast.ps1

. .\config.ps1

$jsonData = convertfrom-json $input

$appid = $jsonData.appid
$msgid = $jsonData.id
$msgdate = $jsonData.date
$markdown = $false
$BigImage = $null
$clickurl = $null
if(Get-Member -inputobject $jsonData -name "extras"){
    if(Get-Member -inputobject $jsonData.extras -name "client::notification"){
        if(Get-Member -inputobject $jsonData.extras."client::notification" -name "bigImageUrl"){
            $bigImageUrl = $jsonData.extras."client::notification".bigImageUrl
            $BigImage = New-BTImage -Source $bigImageUrl
        }
        if(Get-Member -inputobject $jsonData.extras."client::notification" -name "click"){
            if(Get-Member -inputobject $jsonData.extras."client::notification".click -name "url"){
                $clickurl = $jsonData.extras."client::notification".click.url
            }
        }
    }
    if(Get-Member -inputobject $jsonData.extras -name "client::display"){
        if(Get-Member -inputobject $jsonData.extras."client::display" -name "contentType"){
            if($jsonData.extras."client::display".contentType -eq "text/markdown"){
                $markdown = $true
            }
        }
    }
}
Invoke-WebRequest https://$domain/application?token=$token |
    %{ (convertfrom-json $_.content) } | where-object {$_.id -eq $appid} | 
        %{ 
            $appname = $_.name
            $icon = $_.image
        } 
if($useHeaders){
    $Header = New-BTHeader -Id $appid -Title $appname   
}
$AppLogo = New-BTImage -Source https://$domain/$icon -AppLogoOverride

$jsonData.title = $jsonData.title.Replace("[char]39","'")
$jsonData.message = $jsonData.message.Replace("[char]39","'")

$TextHeading = New-BTText -Text $jsonData.title
if (($markdown) -and ($jsonData.message.Contains("![]("))){
    $messageText = ($jsonData.message -split [regex]::Escape("![]("))[0].Trim() 
    $TextBody = New-BTText -Text $messageText
    
    $imageString = ($jsonData.message -split [regex]::Escape("![]("))[1].Split(")")[0]
    $BigImage = New-BTImage -Source $imageString
}else{
    $TextBody = New-BTText -Text $jsonData.message
}
if ($BigImage) {
    $Binding = New-BTBinding -Children $TextHeading, $TextBody, $BigImage -AppLogoOverride $AppLogo     
}else{
    $Binding = New-BTBinding -Children $TextHeading, $TextBody -AppLogoOverride $AppLogo
}
$Visual = New-BTVisual -BindingGeneric $Binding
if($clickurl){
    $UrlButton = New-BTButton -Content 'Details' -Arguments $clickurl
    $Actions = New-BTAction -Buttons $UrlButton
    $Content = New-BTContent -Visual $Visual -Header $Header -CustomTimestamp $msgdate -Actions $Actions
}else{
    $Content = New-BTContent -Visual $Visual -Header $Header -CustomTimestamp $msgdate
}

$Dismissed = {
    . .\config.ps1
    if ($Event.SourceArgs[1].Reason -eq 'UserCanceled') {
        $msgid = $Event.SourceArgs.Tag
        if(Test-Path -Path ".\cache\$msgid.jpg" -PathType Leaf){
            Remove-Item -Path ".\cache\$msgid.jpg" 
        }
        Invoke-RestMethod "https://$domain/message/$msgid" -SessionVariable session -Method Delete -Headers @{"X-Gotify-Key" = $token}
        Stop-Process -Id $PID
    }
}

$Activated = {
    . .\config.ps1
    $msgid = $Event.SourceArgs.Tag
    if(Test-Path -Path ".\cache\$msgid.jpg" -PathType Leaf){
        Remove-Item -Path ".\cache\$msgid.jpg" 
    }
    Invoke-RestMethod "https://$domain/message/$msgid" -SessionVariable session -Method Delete -Headers @{"X-Gotify-Key" = $token}
    Stop-Process -Id $PID
}

Submit-BTNotification -Content $Content -UniqueIdentifier $msgid -AppId "scooterpsu!Gotify" -DismissedAction $Dismissed -ActivatedAction $Activated

You can also use Winify (I'm part of the developer team) and it has a very nice set of features! We created it such that it reaches back to Windows 7, just to be sure even old time users can enjoy it.