DockerMachineCompletion.psm1

Param(
    [string[]]$CustomScriptPath
)

function Select-CompletionResult {
    Param(
        [Parameter(Mandatory = $true, ValueFromPipeline = $true)]
        [NativeCommandCompletionResult[]]$CompletionResult,
        [switch]$OptionWithArg
    )

    Process {
        if ($OptionWithArg) {
            $CompletionResult = $CompletionResult |
                Where-Object { $_.CompletionText -Like '-*' -and $_.TextType -NE 'Switch' }
        }
        $CompletionResult
    }
}

function Invoke-CompletionCustomScript {
    Param(
        [Parameter(Mandatory = $true, ValueFromPipeline = $true)]
        [string[]]$Path
    )

    Process {
        foreach ($p in $Path) {
            . $p
        }
    }
}

Invoke-CompletionCustomScript $PSScriptRoot\completers.ps1, $PSScriptRoot\completers4arguments.ps1
if ($CustomScriptPath) {
    Invoke-CompletionCustomScript $CustomScriptPath
}

$argumentCompleter = {
    Param([string]$wordToComplete, $commandAst, $cursorPosition)

    $completerName = 'docker-machine'
    $optionWithArg = $null
    $command = $null
    $counter = 1

    for (; $counter -lt $commandAst.CommandElements.Count; $counter++) {
        $ce = $commandAst.CommandElements[$counter]
        if ($cursorPosition -lt $ce.Extent.EndColumnNumber) {
            break
        }

        if ($optionWithArg) {
            # The argument of $optionWithArg is completed by this $ce
            $optionWithArg = $null
            continue
        }

        $text = $ce.Extent.Text
        if ($text.StartsWith('-')) {
            if ($text -in (Invoke-Completer $completerName -Option -ArgumentList $wordToComplete, $commandAst, $cursorPosition |
                        Select-CompletionResult -OptionWithArg).CompletionText) {
                $optionWithArg = $text
            }
        } elseif (!$command) {
            $command = $text
            $completerName += "_$command"
        }
    }

    if ($optionWithArg) {
        $completerName += "_$optionWithArg"
    }

    # At this point, $completerName is any of the following:
    # 'docker-machine'
    # 'docker-machine_optionWithArg'
    # 'docker-machine_command'
    # 'docker-machine_command_optionWithArg'

    if ($wordToComplete) {
        $wordToCompleteSubstring = $wordToComplete.Substring(0, $cursorPosition - $commandAst.CommandElements[$counter].Extent.StartOffset)
    }

    if ($wordToComplete.StartsWith('-')) {
        $completionResult = Invoke-Completer $completerName -Option -ArgumentList $wordToComplete, $commandAst, $cursorPosition
    } else {
        $completionResult = Invoke-Completer $completerName -Completer -ArgumentList $wordToComplete, $commandAst, $cursorPosition
    }

    $completionResult | Where-Object CompletionText -Like "$wordToCompleteSubstring*"
}

Register-NativeCommandArgumentCompleter docker-machine $argumentCompleter