SlackBot

1.0

SlackBot.psm1

#Sends simple message responses via the RTM API
Function Send-SlackMsg
{
    [cmdletbinding()]
    Param(
        $Text,
        $Channel,
        $ID = (get-date).ticks
    )

    $Prop = @{'id'      = $ID;
              'type'    = 'message';
              'text'    = $Text;
              'channel' = $Channel}

    $Reply = (New-Object –TypeName PSObject –Prop $Prop) | ConvertTo-Json

    $Array = @()
    $Reply.ToCharArray() | ForEach { $Array += [byte]$_ }          
    $Reply = New-Object System.ArraySegment[byte]  -ArgumentList @(,$Array)

    $Conn = $WS.SendAsync($Reply, [System.Net.WebSockets.WebSocketMessageType]::Text, [System.Boolean]::TrueString, $CT)
    While (!$Conn.IsCompleted) { Start-Sleep -Milliseconds 100 }

    Return $ID
}

#Invokes an instance of a bot
Function Start-SlackBot {
    [cmdletbinding()]
    Param(
        $Token = (Import-Clixml Token.xml)  #So I don't accidentally put it on the internet
    )
    #Web API call starts the session and gets a websocket URL to use.
    $RTMSession = Invoke-RestMethod -Uri https://slack.com/api/rtm.start -Body @{token="$Token"}
    Write-Verbose "I am $($RTMSession.self.name)"

    Try{
        Do{
            $WS = New-Object System.Net.WebSockets.ClientWebSocket                                                
            $CT = New-Object System.Threading.CancellationToken                                                   

            $Conn = $WS.ConnectAsync($RTMSession.URL, $CT)                                                  
            While (!$Conn.IsCompleted) { Start-Sleep -Milliseconds 100 }

            Write-Verbose "Connected to $($RTMSession.URL)"

            $Size = 1024
            $Array = [byte[]] @(,0) * $Size
            $Recv = New-Object System.ArraySegment[byte] -ArgumentList @(,$Array)

            While ($WS.State -eq 'Open') {

                $RTM = ""

                Do {
                    $Conn = $WS.ReceiveAsync($Recv, $CT)
                    While (!$Conn.IsCompleted) { Start-Sleep -Milliseconds 100 }

                    $Recv.Array[0..($Conn.Result.Count - 1)] | ForEach { $RTM += [char]$_ }

                } Until ($Conn.Result.Count -lt $Size)

                Write-Verbose "$RTM"

                If ($RTM){
                    $RTM = ($RTM | convertfrom-json)

                    Switch ($RTM){
                        {($_.type -eq 'message') -and (!$_.reply_to)} { 

                            If ( ($_.text -Match "<@$($RTMSession.self.id)>") -or $_.channel.StartsWith("D") ){
                                #A message was sent to the bot

                                # *** Responses go here, for example..***
                                $words = ($_.text.ToLower() -split " ")

                                Switch ($words){
                                    {@("hey","hello","hi") -contains $_} { Send-SlackMsg -Text 'Hello!' -Channel $RTM.Channel }
                                    {@("bye","cya") -contains $_} { Send-SlackMsg -Text 'Goodbye!' -Channel $RTM.Channel }

                                    default { Write-Verbose "I have no response for $_" }
                                }

                            }Else{
                                Write-Verbose "Message ignored as it wasn't sent to @$($RTMSession.self.name) or in a DM channel"
                            }
                        }
                        {$_.type -eq 'reconnect_url'} { $RTMSession.URL = $RTM.url }

                        default { Write-Verbose "No action specified for $($RTM.type) event" }            
                    }
                }
            }   
        } Until (!$Conn)

    }Finally{

        If ($WS) { 
            Write-Verbose "Closing websocket"
            $WS.Dispose()
        }

    }

}