# nighthawk PowerShell plugin — inline ghost text autocomplete
#
# Install: add to $PROFILE: . ~/.config/nighthawk/nighthawk.ps1
# Requires: PSReadLine 2.0+ (ships with PowerShell 5.1+)
# --- Initialization ---
$script:_nh_esc = [char]27
# Disable PSReadLine's built-in prediction to avoid overlap with nighthawk ghost text
try { Set-PSReadLineOption -PredictionSource None } catch {}
# --- Configuration ---
$script:_nh_hint_arrow = if ($env:NIGHTHAWK_HINT_ARROW) { $env:NIGHTHAWK_HINT_ARROW } else { '->' }
# --- State ---
$script:_nh_pipe = 'nighthawk'
$script:_nh_suggestion = ''
$script:_nh_replace_start = -1
$script:_nh_replace_end = -1
$script:_nh_ghost_len = 0
$script:_nh_last_buffer = ''
$script:_nh_tried_start = $false
$script:_nh_backoff_until = [DateTime]::MinValue
# --- Ghost text rendering via ANSI ---
function _nh_render_ghost([string]$ghost) {
if ($ghost.Length -eq 0) { return }
$e = $script:_nh_esc
$script:_nh_ghost_len = $ghost.Length
# Save cursor, gray text, reset color, restore cursor
# Strip double quotes — Windows Terminal renders them as "" inside ANSI regions
$clean = $ghost -replace '"', ''
$script:_nh_ghost_len = $clean.Length
$Host.UI.Write("${e}[s${e}[90m")
$Host.UI.Write($clean)
$Host.UI.Write("${e}[0m${e}[u")
}
function _nh_clear_ghost {
if ($script:_nh_ghost_len -gt 0) {
$e = $script:_nh_esc
# Save cursor, clear to end of line, restore cursor
$Host.UI.Write("${e}[s${e}[0K${e}[u")
$script:_nh_ghost_len = 0
}
$script:_nh_suggestion = ''
$script:_nh_replace_start = -1
$script:_nh_replace_end = -1
}
# --- Auto-start ---
function _nh_ensure_daemon {
if ($script:_nh_tried_start) { return }
$script:_nh_tried_start = $true
$nhCmd = Get-Command nh -ErrorAction SilentlyContinue
if ($nhCmd) { & nh start >$null 2>$null }
}
# --- Daemon communication ---
function _nh_query {
$line = ''; $cursor = 0
[Microsoft.PowerShell.PSConsoleReadLine]::GetBufferState([ref]$line, [ref]$cursor)
# Only suggest when cursor is at end and buffer has content
if ($cursor -ne $line.Length -or $line.Length -lt 2) { return }
if ($line -eq $script:_nh_last_buffer) { return }
# Backoff: skip queries for 5s after connection failure
if ([DateTime]::UtcNow -lt $script:_nh_backoff_until) { return }
$script:_nh_last_buffer = $line
try {
# Escape for JSON (critical for Windows paths: C:\Users → C:\\Users)
$esc_input = $line -replace '\\','\\' -replace '"','\"' -replace "`n",'\n' -replace "`r",'\r'
$esc_cwd = $PWD.Path -replace '\\','\\' -replace '"','\"'
$json = "{`"input`":`"$esc_input`",`"cursor`":$cursor,`"cwd`":`"$esc_cwd`",`"shell`":`"powershell`"}"
$pipe = [System.IO.Pipes.NamedPipeClientStream]::new('.', $script:_nh_pipe, [System.IO.Pipes.PipeDirection]::InOut)
try {
$pipe.Connect(20)
$utf8 = [System.Text.UTF8Encoding]::new($false) # UTF-8 without BOM
$writer = [System.IO.StreamWriter]::new($pipe, $utf8)
$writer.AutoFlush = $true
$writer.WriteLine($json)
$reader = [System.IO.StreamReader]::new($pipe, $utf8)
$readTask = $reader.ReadLineAsync()
if (-not $readTask.Wait(100)) { return }
$response = $readTask.Result
} finally {
$pipe.Dispose()
}
if (-not $response) { return }
$parsed = $response | ConvertFrom-Json
if (-not $parsed.suggestions -or $parsed.suggestions.Count -eq 0) { return }
$s = $parsed.suggestions[0]
$script:_nh_suggestion = $s.text
$script:_nh_replace_start = [int]$s.replace_start
$script:_nh_replace_end = [int]$s.replace_end
if ($s.PSObject.Properties['diff_ops'] -and $null -ne $s.diff_ops) {
# Fuzzy match: render as hint " → suggestion"
_nh_render_ghost " $($script:_nh_hint_arrow) $($s.text)"
} else {
$typed_len = $cursor - $script:_nh_replace_start
if ($typed_len -ge 0 -and $typed_len -lt $s.text.Length) {
$typed_part = $line.Substring($script:_nh_replace_start, $typed_len)
if ($s.text.StartsWith($typed_part, [System.StringComparison]::Ordinal)) {
# True prefix match: show suffix as ghost text
_nh_render_ghost $s.text.Substring($typed_len)
} else {
# Replacement changes typed text: show hint instead
_nh_render_ghost " $($script:_nh_hint_arrow) $($s.text)"
}
}
}
}
catch {
# Back off for 5s so failed connections don't block typing
$script:_nh_backoff_until = [DateTime]::UtcNow.AddSeconds(5)
# Try starting the daemon once
if (-not $script:_nh_tried_start) { _nh_ensure_daemon }
}
}
# --- Accept suggestion ---
function _nh_accept {
if ($script:_nh_suggestion -and $script:_nh_replace_start -ge 0) {
# Save state before _nh_clear_ghost wipes it
$text = $script:_nh_suggestion
$start = $script:_nh_replace_start
$end = $script:_nh_replace_end
_nh_clear_ghost
$len = $end - $start
[Microsoft.PowerShell.PSConsoleReadLine]::Replace($start, $len, $text)
$script:_nh_last_buffer = ''
}
}
# --- Key bindings ---
# Handler for printable character input
$_nh_insert_handler = {
param($key, $arg)
_nh_clear_ghost
[Microsoft.PowerShell.PSConsoleReadLine]::SelfInsert($key, $arg)
_nh_query
}
# Bind common command-line characters (PS 5.1 compat: use int ranges, not char ranges)
$_nh_bind_chars = @()
$_nh_bind_chars += 97..122 | ForEach-Object { [string][char]$_ } # a-z
$_nh_bind_chars += 65..90 | ForEach-Object { [string][char]$_ } # A-Z
$_nh_bind_chars += 48..57 | ForEach-Object { [string][char]$_ } # 0-9
$_nh_bind_chars += @('-','_','.','/','\',':','~','=','+','@','#','$','%','^','&','*',',',';','!','|','Spacebar')
foreach ($c in $_nh_bind_chars) {
Set-PSReadLineKeyHandler -Chord $c -ScriptBlock $_nh_insert_handler
}
Set-PSReadLineKeyHandler -Chord 'Backspace' -ScriptBlock {
param($key, $arg)
_nh_clear_ghost
[Microsoft.PowerShell.PSConsoleReadLine]::BackwardDeleteChar($key, $arg)
_nh_query
}
Set-PSReadLineKeyHandler -Chord 'Tab' -ScriptBlock {
param($key, $arg)
if ($script:_nh_suggestion) {
_nh_accept
} else {
[Microsoft.PowerShell.PSConsoleReadLine]::TabCompleteNext($key, $arg)
}
}
Set-PSReadLineKeyHandler -Chord 'RightArrow' -ScriptBlock {
param($key, $arg)
$line = ''; $cursor = 0
[Microsoft.PowerShell.PSConsoleReadLine]::GetBufferState([ref]$line, [ref]$cursor)
if ($script:_nh_suggestion -and $cursor -eq $line.Length) {
_nh_accept
} else {
[Microsoft.PowerShell.PSConsoleReadLine]::ForwardChar($key, $arg)
}
}
Set-PSReadLineKeyHandler -Chord 'Enter' -ScriptBlock {
param($key, $arg)
_nh_clear_ghost
[Microsoft.PowerShell.PSConsoleReadLine]::AcceptLine($key, $arg)
}
Set-PSReadLineKeyHandler -Chord 'Escape' -ScriptBlock {
param($key, $arg)
if ($script:_nh_ghost_len -gt 0) {
_nh_clear_ghost
} else {
[Microsoft.PowerShell.PSConsoleReadLine]::RevertLine($key, $arg)
}
}