# Copyright (c) 2017 Ansible Project
# Simplified BSD License (see licenses/simplified_bsd.txt or https://opensource.org/licenses/BSD-2-Clause)

Function Convert-FromSID($sid) {
    # Converts a SID to a Down-Level Logon name in the form of DOMAIN\UserName
    # If the SID is for a local user or group then DOMAIN would be the server
    # name.

    $account_object = New-Object System.Security.Principal.SecurityIdentifier($sid)
    try {
        $nt_account = $account_object.Translate([System.Security.Principal.NTAccount])
    } catch {
        Fail-Json -obj @{} -message "failed to convert sid '$sid' to a logon name: $($_.Exception.Message)"
    }
    
    return $nt_account.Value
}

Function Convert-ToSID($account_name) {
    # Converts an account name to a SID, it can take in the following forms
    # UPN:
    #   principal@domain (Domain users only)
    # Down-Level Login Name
    #   DOMAIN\principal (Domain)
    #   SERVERNAME\principal (Local)
    #   .\principal (Local)
    #   NT AUTHORITY\SYSTEM (Local Service Accounts)
    # Login Name
    #   principal (Local/Local Service Accounts)

    if ($account_name -like "*\*") {
        $account_name_split = $account_name -split "\\"
        if ($account_name_split[0] -eq ".") {
            $domain = $env:COMPUTERNAME
        } else {
            $domain = $account_name_split[0]
        }
        $username = $account_name_split[1]
    } elseif ($account_name -like "*@*") {
        $account_name_split = $account_name -split "@"
        $domain = $account_name_split[1]
        $username = $account_name_split[0]
    } else {
        $domain = $null
        $username = $account_name
    }

    if ($domain) {
        # searching for a local group with the servername prefixed will fail,
        # need to check for this situation and only use NTAccount(String)
        if ($domain -eq $env:COMPUTERNAME) {
            $adsi = [ADSI]("WinNT://$env:COMPUTERNAME,computer")
            $group = $adsi.psbase.children | Where-Object { $_.schemaClassName -eq "group" -and $_.Name -eq $username }
        } else {
            $group = $null
        }
        if ($group) {
            $account = New-Object System.Security.Principal.NTAccount($username)
        } else {
            $account = New-Object System.Security.Principal.NTAccount($domain, $username)
        }
    } else {
        # when in a domain NTAccount(String) will favour domain lookups check
        # if username is a local user and explictly search on the localhost for
        # that account
        $adsi = [ADSI]("WinNT://$env:COMPUTERNAME,computer")
        $user = $adsi.psbase.children | Where-Object { $_.schemaClassName -eq "user" -and $_.Name -eq $username }
        if ($user) {
            $account = New-Object System.Security.Principal.NTAccount($env:COMPUTERNAME, $username)
        } else {
            $account = New-Object System.Security.Principal.NTAccount($username)
        }
    }
    
    try {
        $account_sid = $account.Translate([System.Security.Principal.SecurityIdentifier])
    } catch {
        Fail-Json @{} "account_name $account_name is not a valid account, cannot get SID: $($_.Exception.Message)"
    }
    
    return $account_sid.Value
}

# this line must stay at the bottom to ensure all defined module parts are exported
Export-ModuleMember -Alias * -Function * -Cmdlet *
