param(
    [Parameter(Mandatory=$true)]
    [ValidateSet("left","right","middle","double","scroll_up","scroll_down")]
    [string]$Action
)

Add-Type -Name MouseM -Namespace Win32 -MemberDefinition @'
[DllImport("user32.dll")]
public static extern void mouse_event(uint flags, int dx, int dy, int data, System.UIntPtr extra);
'@

$LEFTDOWN  = 0x0002
$LEFTUP    = 0x0004
$RIGHTDOWN = 0x0008
$RIGHTUP   = 0x0010
$MIDDOWN   = 0x0020
$MIDUP     = 0x0040
$WHEEL     = 0x0800

function Click([uint32]$down, [uint32]$up) {
    [Win32.MouseM]::mouse_event($down, 0, 0, 0, [UIntPtr]::Zero)
    Start-Sleep -Milliseconds 30
    [Win32.MouseM]::mouse_event($up,   0, 0, 0, [UIntPtr]::Zero)
}

switch ($Action) {
    "left"        { Click $LEFTDOWN  $LEFTUP }
    "right"       { Click $RIGHTDOWN $RIGHTUP }
    "middle"      { Click $MIDDOWN   $MIDUP }
    "double"      { Click $LEFTDOWN  $LEFTUP; Start-Sleep -Milliseconds 50; Click $LEFTDOWN $LEFTUP }
    "scroll_up"   { [Win32.MouseM]::mouse_event($WHEEL, 0, 0,  360, [UIntPtr]::Zero) }
    "scroll_down" { [Win32.MouseM]::mouse_event($WHEEL, 0, 0, -360, [UIntPtr]::Zero) }
}