TerraformCompleter

0.0.1

private/Get-TerraformCommandGrammar.ps1

function Get-TerraformCommandGrammar
{
    [CmdletBinding()]
    param(
        [Parameter(Mandatory)]
        [string[]] $Command
    )

    $Grammar = @{ Commands = @(); Options = @() }

    $Executable = $Command[0]
    $Arguments = $Command[1..$Command.Length]
    $Output = &$Executable $Arguments -help

    Write-Verbose "Exporting grammar for '$($Command -join ' ')'..."

    $Mode = $null
    $CurrentOption = $null

    foreach($Line in $Output)
    {
        if($Line.StartsWith("Main commands:") -or $Line.StartsWith("All other commands:") -or $Line.StartsWith("Subcommands:"))
        {
            Write-Debug "[$($Command -join ' ')] Found beginning of commands ($Line)"
            $Mode = 'Commands'
            continue
        }
        elseif($Line.StartsWith("Global options") -or $Line -match "^[a-zA-Z ]*Options:$")
        {
            Write-Debug "[$($Command -join ' ')] Found beginning of options ($Line)"
            $Mode = 'Options'
            continue
        }

        if($null -eq $Mode)
        {
            continue 
        }

        $LineParts = $Line -split '\s{2,}' |
            Where-Object { -not [string]::IsNullOrEmpty($_) } |
            ForEach-Object { $_.Trim() }

        Write-Debug "[$($Command -join ' ')][$Mode] Processing line: '$($LineParts -join ' ')'"

        switch($Mode)
        {
            # Only found command one-liner in TF output
            'Commands'
            {
                # Empty line separator
                if([string]::IsNullOrEmpty($Line))
                {
                    continue
                }

                $Name, $Description = $LineParts

                # Subcommands
                $Subgrammar = Get-TerraformCommandGrammar -Command ($Command + @($Name))

                $Grammar.Commands += @{
                    Name = $Name
                    Description = $Description
                    Commands = $Subgrammar.Commands
                    Options = $Subgrammar.Options
                }
            }

            # Options can have description on multiple line
            # And have empty line between definition
            'Options'
            {
                # New option (-<name> <description>)
                if($Line -match "^\s*-")
                {

                    if($null -ne $CurrentOption)
                    {
                        Write-Debug "[$($Command -join ' ')][$Mode] End of option '$($CurrentOption.Name)'"
                        $Grammar.Options += $CurrentOption
                        $CurrentOption = $null
                    }

                    $Parameter, $Description = $LineParts

                    $ParameterWithoutEqualParts = $Parameter -split ' '

                    # Special case (terraform plan -var)
                    if($ParameterWithoutEqualParts.Length -gt 1)
                    {
                        $ParameterName, $ParameterValue = $ParameterWithoutEqualParts
                    }
                    else
                    {
                        $ParameterName, $ParameterValue = $Parameter.Split('=')
                    }


                    Write-Debug "[$($Command -join ' ')][$Mode] Start of option '$ParameterName' ($Line)"

                    $CurrentOption = @{
                        Name = $ParameterName.TrimStart('-')
                        Description = $Description
                    }

                    if($null -eq $ParameterValue)
                    {
                        $CurrentOption.Flag = $true
                    }

                    if($ParameterValue -match 'file|path|DIR')
                    {
                        $CurrentOption.PathValue = $true
                    }
                    
                    if($ParameterValue -in @('true', 'false'))
                    {
                        $CurrentOption.AllowedValues = @('true', 'false')
                    }
                }
                # Description line or empty line
                elseif($null -ne $CurrentOption)
                {
                    $CurrentOption.Description += "`n$($Line.Trim())"
                }
            }
        }
    }

    if($null -ne $CurrentOption)
    {
        $Grammar.Options += $CurrentOption
    }

    return $Grammar
}