Prototype PowerShell support for atuin

atuin.psm1

$PSReadLine = Get-Module PSReadLine
$atuin = Get-Command atuin -ErrorAction Ignore

if (!$PSReadLine -or !$atuin) {
    Write-Host "PSReadLine and atuin are required"
    return
}

$env:ATUIN_SESSION = atuin uuid

$atuin_history_id = 0

function PSConsoleHostReadLine {
    ## This needs to be done as the first thing because any script run will flush $?.
    $lastRunStatus = $?

    if ($atuin_history_id -ne 0) {
        $exitCode = if ($lastRunStatus) { 0 } elseif ($LASTEXITCODE) { $LASTEXITCODE } else { 1 }
        $null = atuin history end --exit $exitCode -- $atuin_history_id
    }

    Microsoft.PowerShell.Core\Set-StrictMode -Off
    $line = [Microsoft.PowerShell.PSConsoleReadLine]::ReadLine($host.Runspace, $ExecutionContext, $lastRunStatus)

    $script:atuin_history_id = atuin history start -- $line
    $line
}

Set-PSReadLineKeyHandler -Key Ctrl+r -ScriptBlock {
    $line = $null
    $cursor = $null
    [Microsoft.PowerShell.PSConsoleReadLine]::GetBufferState([ref]$line, [ref]$cursor)
    $resultFile = New-TemporaryFile
    Start-Process -Wait -NoNewWindow -RedirectStandardError $resultFile.FullName atuin -ArgumentList "search","-i"
    $result = (Get-Content -Raw $resultFile).Trim()
    Remove-Item $resultFile

    [Microsoft.PowerShell.PSConsoleReadLine]::RevertLine()
    [Microsoft.PowerShell.PSConsoleReadLine]::Insert($result)
}

$MyInvocation.MyCommand.ScriptBlock.Module.OnRemove = {
    Write-Host "To restore PSReadLine, run`n    Remove-Module PSReadLine`n    Import-Module PSReadLine"
}

Export-ModuleMember -Function PSConsoleHostReadLine