class HostCheck {
    [string] $HostName = ""
    [string] $Fqdn = ""
    [string] $CName = ""
    [string] $IpAddress = ""
    [bool] $Exists = $false
    [bool] $RegisteredInExternalDNS = $false;
}

function HostExistsInExternal ([HostCheck] $hostCheck, [string] $ExternalDNSServer) {
    try {
        $CnameChain = resolve-dnsname -name $hostCheck.Fqdn -DnsOnly -Type A -NoHostsFile -Server $ExternalDNSServer -ErrorAction Ignore

        foreach ($chainItem in $CnameChain) {
            if ($chainItem.NameHost -ieq $hostCheck.CName) {
                $hostCheck.RegisteredInExternalDNS = $true
                return $hostCheck
            }
        }
    }
    catch {
        $hostCheck.RegisteredInExternalDNS = $false
    }

    $hostCheck.RegisteredInExternalDNS = $false
    return $hostCheck
}

function GetIPAddress ([HostCheck] $hostCheck) {
    try {
        $hostAddresses = [System.Net.Dns]::GetHostAddresses($hostCheck.Fqdn)

        $hostCheck.IpAddress = $hostAddresses.IPAddressToString
        $hostCheck.Exists = $true
    }
    catch { 
        try {
            $hostAddresses = [System.Net.Dns]::GetHostAddresses($hostCheck.HostName)

            $hostCheck.IpAddress = $hostAddresses.IPAddressToString
            $hostCheck.Exists = $true
        }
        catch {
            $hostCheck.IpAddress = ""
            $hostCheck.Exists = $false
        }

    }
    return $hostCheck
}

function Effectory-DNSVerify (
    [string] $ZoneName = "effectory.com", 
    [string] $DNSServer = "DC1.effectory.local",
    [string] $ExternalDNSServer = "8.8.8.8",
    [string] $Type = "CName") {
    
    Clear-DnsClientCache

    $DNSRecords = Get-DnsServerResourceRecord -ZoneName $ZoneName -computername $DNSServer -RRType $Type

    # HostName                  RecordType Type       Timestamp            TimeToLive      RecordData
    # --------                  ---------- ----       ---------            ----------      ----------
    # accept                    CNAME      5          0                    01:00:00        effectorycorporate2-accept.azurewebsites.net.
    # accept-authorization      CNAME      5          0                    01:00:00        authorization-web-api-accept.azurewebsites.net.
    # accept-beta-project       CNAME      5          0                    01:00:00        webclient-project-accept.azurewebsites.net.
    # accept-cluster            CNAME      5          0                    01:00:00        test-cluster-effectory-accept.azurewebsites.net.
    # accept-customer           CNAME      5          0                    01:00:00        test-customer-effectory-accept.azurewebsites.net.
    # accept-dashboard          CNAME      5          0                    01:00:00        dashboard-effectory-accept.azurewebsites.net.

    [HostCheck[]]$Result = @()

    foreach ($DNSRecord in $DNSRecords) {

        [HostCheck] $hostCheck = [HostCheck]::new()
        $hostCheck.HostName = $DNSRecord.HostName
        
        [string] $fqdn = $DNSRecord.HostName
        if (-not ($fqdn.ToLowerInvariant().EndsWith($ZoneName.ToLowerInvariant()))) {
            $fqdn = "$($DNSRecord.HostName).$($ZoneName)"
        }
        $hostCheck.Fqdn = $fqdn

        [string] $cname = $DNSRecord.RecordData.HostNameAlias
        if ($cname.EndsWith(".")) {
            $cname = $cname.Remove($cname.Length - 1, 1)
        }
        $hostCheck.CName = $cname

        $hostCheck = HostExistsInExternal -host $hostCheck -ExternalDNSServer $ExternalDNSServer
        $hostCheck = GetIPAddress -host $hostCheck

        $Result += $hostCheck
    }

    return $Result
}

function Effectory-DNSVerify-Csv (
    [string[]] $FileName, 
    [string] $ExternalDNSServer = "8.8.8.8") {
    
    Clear-DnsClientCache
    
    $DNSRecords = import-csv $FileName -Header 'HostName', 'Cname', 'Fqdn'

    # HostName,Cname,Fqdn
    # accept-authorization,authorization-web-api-accept.azurewebsites.net,accept-authorization.effectory.com
    # accept-customer,test-customer-effectory-accept.azurewebsites.net,accept-customer.effectory.com
    # accept-ecestore,test-ecestore-accept.azurewebsites.net,accept-ecestore.effectory.com

    [HostCheck[]]$Result = @()
    foreach ($DNSRecord in $DNSRecords) {

        [HostCheck] $hostCheck = [HostCheck]::new()
        $hostCheck.HostName = $DNSRecord.HostName
        $hostCheck.CName = $DNSRecord.Cname
        $hostCheck.Fqdn = $DNSRecord.Fqdn

        $hostCheck = HostExistsInExternal -host $hostCheck -ExternalDNSServer $ExternalDNSServer
        $hostCheck = GetIPAddress -host $hostCheck

        $Result += $hostCheck
    }
    
    return $Result
}

function Effectory-DNSClean-Csv (
    [string[]] $FileName, 
    [string] $DNSServer = "DC1.effectory.local",
    [string] $Type = "CNAME") {
    
    Clear-DnsClientCache
    
    $DNSRecords = import-csv $FileName -Header 'HostName', 'ZoneName'

    # HostName,ZoneName
    # accountmanagertools,effectory.local
    # alex,effectory.local
    # webstage.beste-werkgevers,effectory.local

    foreach ($DNSRecord in $DNSRecords) {
        
        if (($DNSRecord.HostName -eq "HostName")) {
            continue;
        }

        Write-Host "Deleting $($DNSRecord.HostName) from $($DNSRecord.ZoneName)"

        try {
            Remove-DnsServerResourceRecord -ComputerName $DNSServer -ZoneName $DNSRecord.ZoneName -RRType $Type -Name $DNSRecord.HostName -Force 
        }
        catch { }
    }
}


#Effectory-DNSVerify -ZoneName "effectory.com" -DNSServer "DC1.effectory.local" -ExternalDNSServer "8.8.8.8" | Export-Csv -Path .\DNS-effectory-com.csv
#Effectory-DNSVerify -ZoneName "effectory.local" -DNSServer "DC1.effectory.local" -ExternalDNSServer "DC2.effectory.local" | Export-Csv -Path .\DNS-effectory-local.csv
Effectory-DNSVerify-Csv -FileName .\Book1.csv -ExternalDNSServer "8.8.8.8" | Export-Csv -Path .\DNS-vip.csv

# | Format-Table
# | Export-Csv -Path .\DNS-xxxx.csv

#Effectory-DNSClean-Csv -FileName .\deletedns.csv -DNSServer "DC1.effectory.local"