PSFzf.psm1

$script:IsWindows = Get-Variable IsWindows -Scope Global -ErrorAction SilentlyContinue
if ($script:IsWindows -eq $null -or $script:IsWindows.Value -eq $true) {
    $script:AppName = 'fzf.exe'
    $script:IsWindows = $true
} else {
    $script:AppName = 'fzf'    
    $script:IsWindows = $false
}
$script:FzfLocation = $null
$script:PSReadlineHandlerChord = $null
$MyInvocation.MyCommand.ScriptBlock.Module.OnRemove =
{
    if ($script:PSReadlineHandlerChord -ne $null) {
        Remove-PSReadlineKeyHandler $script:PSReadlineHandlerChord
    }
}

function Invoke-Fzf {
    param( 
            [Alias("x")]
            [switch]$Extended,
            [Alias('e')]
              [switch]$ExtendedExact,
            [Alias('i')]
              [switch]$CaseInsensitive,
              [switch]$CaseSensitive,
              [Alias('d')]
              [string]$Delimiter,
              [switch]$NoSort,
            [Alias('tac')]
              [switch]$ReverseInput,
              [ValidateSet('length','begin','end','index')]
              [string]
              $Tiebreak = 'length',
            [Alias('m')]
              [switch]$Multi,
            #[switch]$Ansi,
            [switch]$NoMouse,
            #$Color,
            [switch]$Black,
            [switch]$Reverse,
            [switch]$Cycle,
            [switch]$NoHScroll,
            [switch]$InlineInfo,
            [string]$Prompt,
            #[string]$Bind,
            [string]$History,
            [int]$HistorySize = -1,
            
            [Alias('q')]
            [string]$Query,
            [Alias('1')]
            [switch]$Select1,
            [Alias('0')]
            [switch]$Exit0,
            [Alias('f')]
            [string]$Filter,
            
              [Parameter(ValueFromPipeline=$True)]
            [string[]]$Input
    )

    Begin {
        # process parameters:
        $arguments = ''
        if ($Extended)                                     { $arguments += '--extended '}
        if ($ExtendedExact)                             { $arguments += '--extended-exact '}
        if ($CaseInsensitive)                             { $arguments += '-i '}
        if ($CaseSensitive)                             { $arguments += '+i '}
        if (![string]::IsNullOrWhiteSpace($Delimiter))     { $arguments += "--delimiter=$Delimiter "}
        if ($NoSort)                                     { $arguments += '--no-sort '}
        if ($ReverseInput)                                 { $arguments += '--tac '}
        if (![string]::IsNullOrWhiteSpace($Tiebreak))    { $arguments += "--tiebreak=$Tiebreak "}
        if ($Multi)                                     { $arguments += '--multi '}
        if ($NoMouse)                                     { $arguments += '--no-mouse '}
        if ($Black)                                     { $arguments += '--black '}
        if ($Reverse)                                     { $arguments += '--reverse '}
        if ($Cycle)                                         { $arguments += '--cycle '}
        if ($NoHScroll)                                 { $arguments += '--no-hscroll '}
        if ($InlineInfo)                                 { $arguments += '--inline-info '}
        if (![string]::IsNullOrWhiteSpace($Prompt))     { $arguments += "--prompt='$Prompt' "}
        if ($History)                                     { $arguments += "--history='$History' "}
        if ($HistorySize -ge 1)                            { $arguments += "--history-size=$HistorySize "}
        if (![string]::IsNullOrWhiteSpace($Query))        { $arguments += "--query=$Query "}
        if ($Select1)                                    { $arguments += '--select-1 '}
        if ($Exit0)                                        { $arguments += '--exit-0 '}
        if (![string]::IsNullOrWhiteSpace($Filter0))    { $arguments += "--filter=$Filter " }
    
        # prepare to start process:
        $process = New-Object System.Diagnostics.Process
        $process.StartInfo.FileName = $script:FzfLocation
        $process.StartInfo.Arguments = $arguments
        $process.StartInfo.RedirectStandardInput = 1
        $process.StartInfo.RedirectStandardOutput = 1
        $process.StartInfo.UseShellExecute = 0
        
        # Creating string builders to store stdout:
        $stdOutStr = New-Object -TypeName System.Text.StringBuilder

        # Adding event handers for stdout:
        $scripBlock = {
            if (! [String]::IsNullOrEmpty($EventArgs.Data)) {
                $Event.MessageData.AppendLine($EventArgs.Data)
            }
        }
        $stdOutEvent = Register-ObjectEvent -InputObject $process `
        -Action $scripBlock -EventName 'OutputDataReceived' `
        -MessageData $stdOutStr

        $process.Start() | Out-Null
        $process.BeginOutputReadLine() | Out-Null
    }

    Process {
        try {
            foreach ($i in $Input) {
                $process.StandardInput.WriteLine($i)
            }
            $process.StandardInput.Flush()
        } catch {
            # do nothing
        }

        # if process has exited, stop pipeline:
        if ($process.HasExited) {
            Unregister-Event -SourceIdentifier $stdOutEvent.Name
            $stdOutStr.ToString()
            break
        }
    }

    End {
       $process.StandardInput.Close() | Out-Null
        $process.WaitForExit() | Out-Null
        Unregister-Event -SourceIdentifier $stdOutEvent.Name | Out-Null
        $stdOutStr.ToString()
    }
}

function Find-CurrentPath {
    param([string]$line,[int]$cursor,[ref]$leftCursor,[ref]$rightCursor)
    
    if ($line.Length -eq 0) {
        $leftCursor.Value = $rightCursor.Value = 0
        return $null
    }

    if ($cursor -ge $line.Length) {
        $leftCursorTmp = $cursor - 1
    } else {
        $leftCursorTmp = $cursor
    }
    :leftSearch for (;$leftCursorTmp -ge 0;$leftCursorTmp--) {
        if ([string]::IsNullOrWhiteSpace($line[$leftCursorTmp])) {
            if (($leftCursorTmp -lt $cursor) -and ($leftCursorTmp -lt $line.Length-1)) {
                $leftCursorTmpQuote = $leftCursorTmp - 1
                $leftCursorTmp = $leftCursorTmp + 1
            } else {
                $leftCursorTmpQuote = $leftCursorTmp
            }
            for (;$leftCursorTmpQuote -ge 0;$leftCursorTmpQuote--) {
                if (($line[$leftCursorTmpQuote] -eq '"') -and (($leftCursorTmpQuote -le 0) -or ($line[$leftCursorTmpQuote-1] -ne '"'))) {
                    $leftCursorTmp = $leftCursorTmpQuote
                    break leftSearch
                }
                elseif (($line[$leftCursorTmpQuote] -eq "'") -and (($leftCursorTmpQuote -le 0) -or ($line[$leftCursorTmpQuote-1] -ne "'"))) {
                    $leftCursorTmp = $leftCursorTmpQuote
                    break leftSearch
                }
            }
            break leftSearch
        }
    }
    :rightSearch for ($rightCursorTmp = $cursor;$rightCursorTmp -lt $line.Length;$rightCursorTmp++) {
        if ([string]::IsNullOrWhiteSpace($line[$rightCursorTmp])) {
            if ($rightCursorTmp -gt $cursor) {
                $rightCursorTmp = $rightCursorTmp - 1
            }
            for ($rightCursorTmpQuote = $rightCursorTmp+1;$rightCursorTmpQuote -lt $line.Length;$rightCursorTmpQuote++) {
                if (($line[$rightCursorTmpQuote] -eq '"') -and (($rightCursorTmpQuote -gt $line.Length) -or ($line[$rightCursorTmpQuote+1] -ne '"'))) {
                    $rightCursorTmp = $rightCursorTmpQuote
                    break rightSearch
                }
                elseif (($line[$rightCursorTmpQuote] -eq "'") -and (($rightCursorTmpQuote -gt $line.Length) -or ($line[$rightCursorTmpQuote+1] -ne "'"))) {
                    $rightCursorTmp = $rightCursorTmpQuote
                    break rightSearch
                }
            }
            break rightSearch
        }
    }
    if ($leftCursorTmp -lt 0 -or $leftCursorTmp -gt $line.Length-1) { $leftCursorTmp = 0}
    if ($rightCursorTmp -ge $line.Length) { $rightCursorTmp = $line.Length-1 }
    $leftCursor.Value = $leftCursorTmp
    $rightCursor.Value = $rightCursorTmp
    $str = -join ($line[$leftCursorTmp..$rightCursorTmp])
    return $str.Trim("'").Trim('"')
}

function Invoke-FzfPsReadlineHandler {
    $leftCursor = $null
    $rightCursor = $null
    $line = $null
    $cursor = $null
    [Microsoft.PowerShell.PSConsoleReadline]::GetBufferState([ref]$line, [ref]$cursor)
    $currentPath = Find-CurrentPath $line $cursor ([ref]$leftCursor) ([ref]$rightCursor)
    $addSpace = $currentPath -ne $null -and $currentPath.StartsWith(" ")
    if ([String]::IsNullOrWhitespace($currentPath) -or !(Test-Path $currentPath)) {
        $currentPath = $null
    }
    $result = Invoke-Fzf $currentPath
    if ($result -ne $null) {

        # quote strings if we need to:
        if ($result -is [system.array]) {
            for ($i = 0;$i -lt $result.Length;$i++) {
                if ($result[$i].Contains(" ") -or $result[$i].Contains("`t")) {
                    $result[$i] = "'{0}'" -f $result[$i]
                }
            }
        } else {
            if ($result.Contains(" ") -or $result.Contains("`t")) {
                    $result = "'{0}'" -f $result
            }
        }
        
        $str = $result -join ','
        if ($addSpace) {
            $str = ' ' + $str
        }
        $replaceLen = $rightCursor - $leftCursor
        if ($rightCursor -eq 0 -and $leftCursor -eq 0) {
            [Microsoft.PowerShell.PSConsoleReadLine]::Insert($str)
        } else {
            [Microsoft.PowerShell.PSConsoleReadLine]::Replace($leftCursor,$replaceLen+1,$str)
        }        
    }
}
 
# install PSReadline shortcut:
if (Get-Module -ListAvailable -Name PSReadline) {
    if ($args.Length -ge 1) {
        $script:PSReadlineHandlerChord = $args[0] 
    } else {
        $script:PSReadlineHandlerChord = 'Ctrl+T'
    }
    if (Get-PSReadlineKeyHandler -Bound | Where Key -eq $script:PSReadlineHandlerChord) {
        Write-Warning ("PSReadline chord {0} already in use - keyboard handler not installed" -f $script:PSReadlineHandlerChord)
    } else {
        Set-PSReadlineKeyHandler -Key Ctrl+T -BriefDescription "Invoke Fzf" -ScriptBlock  {
            Invoke-FzfPsReadlineHandler
        }
    } 
} else {
    Write-Warning "PSReadline module not found - keyboard handler not installed" 
}


# find location of fzf executable:
$script:FzfLocation = Get-Command $script:AppName
if ($script:FzfLocation -ne $null) {
    $script:FzfLocation = $script:FzfLocation.Source
} else {
    if ([string]::IsNullOrWhiteSpace($env:GOPATH)) {
        throw 'environment variable GOPATH not set'
    }
    $script:FzfLocation = Join-Path $env:GOPATH (Join-Path 'bin' $script:AppName) 
}
if ($script:FzfLocation -eq $null) {
    throw "Failed to find '{0}' in path" -f $script:AppName 
}