Dependency resolving algorithm

Resolve-Dependency.ps1

class Configuration {
    [string]   $Name
    [string[]] $DependsOnNames
}

$Configurations = @{
}

$Configurations += @{ 
    configuration1 = [Configuration]@{
        Name = "configuration1"
        DependsOnNames = @()
    }
}

$Configurations += @{ 
    configuration2 = [Configuration]@{
        Name = "configuration2"
        DependsOnNames = @("configuration1")
    }
}

$Configurations += @{ 
    configuration3 = [Configuration]@{
        Name = "configuration3"
        DependsOnNames = @("configuration1", "configuration2")
    }
}

$resolved = @()

while ($Configurations.Keys.Count -ne 0) {
    $currentDepency = $null
    foreach ($configurationName in $Configurations.Keys) {
        $configuration = $Configurations[$configurationName]

        if ($configuration.DependsOnNames.Count -eq 0) {
            $currentDepency = $configuration.Name
        }
    }

    if (($null -eq $currentDepency)) {
        $ErrorMessage =  "Unable to resolve configuration depencies: Circular dependency`r`n"
        $ErrorMessage += "Unresolved configuration:`r`n"
        foreach ($configurationName in $Configurations.Keys) {
            $ErrorMessage += ("$configurationName : " + ($Configurations[$configurationName].DependsOnNames) + "`r`n") 
        }
        Write-Error $ErrorMessage
        return
    }

    if (($null -eq $Configurations[$currentDepency])) {
        Write-Error "Configuration dependency $currentDepency is not found"
        return
    }

    $Configurations.Remove($currentDepency)

    foreach ($configurationName in $Configurations.Keys) {
        $Configurations[$configurationName].DependsOnNames = $Configurations[$configurationName].DependsOnNames.Where({ $_ -ne $currentDepency })
    }

    $resolved += $currentDepency
}

Write-Host "Resolved:"

$resolved