if (Get-Module posh-venv) { return }

function CompleteVenvName {
    param($commandName, $parameterName, $wordToComplete,
        $commandAst, $fakeBoundParameters)

    Get-ChildItem -Directory $env:WORKON_HOME
    | ForEach-Object { $_.Name }
    | Where-Object { $_ -Like "$wordToComplete*" }
    | Sort-Object
}


function venv {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory = $true)]
        [ValidateSet("list", "activate", "deactivate")]
        $command,

        [Parameter(Mandatory = $false)]
        [ArgumentCompleter({ CompleteVenvName @args })]
        $venv)
    switch ($command) {
        "list" {
            @(Get-ChildItem -Directory $env:WORKON_HOME | ForEach-Object {
                    $name = $_.Name
                    $version = (& "$_/Scripts/python.exe" --version).Replace("Python ", "")
                    @{Name = $name; Version = $version; Path = $_ }
                }) | ForEach-Object {
                New-Object object | Add-Member -NotePropertyMembers $_ -PassThru
            }
        }

        "activate" {
            if (Test-Path "$env:WORKON_HOME/$venv/Scripts/activate.ps1") {
                & "$env:WORKON_HOME/$venv/Scripts/activate.ps1"
            }
            elseif ((!$venv -Or !$venv.Trim()) -And (Test-Path "venv/Scripts/activate.ps1")) {
                & "venv/Scripts/activate.ps1"
            }
            elseif (Test-Path (Join-Path $PWD $venv)) {
                & "$venv/Scripts/activate.ps1"
            }
            else {
                Write-Error "Environment '${venv}' does not exists."
            }
        }

        "deactivate" {
            deactivate
        }

        "list-python" {
            py -0 | Select-Object -Skip 1
        }

        default {
            Write-Error "Unknown venv command ${args[0]}."
        }
    }
}