# 参考
# https://github.com/disco-v8/DirectEdit/blob/master/txtregist.php
param(
    [Parameter(Mandatory)]
    [ValidateSet('create','delete')]
    [string]$Action,
    [Parameter(Mandatory)]
    [string]$Identifier,
    [Parameter(Mandatory)]
    [string]$RecordName,
    [Parameter(Mandatory)]
    [string]$Token
)

$MyDnsUrl      = 'https://www.mydns.jp/directedit.html'
$MyDnsMasterId = 'YOURMASTERID'
$MyDnsPassword = 'YOURMASTERPWD'

switch ($Action) {
    'create' {
        $EditCmd = 'REGIST'
    }
    'delete' {
        $EditCmd = 'DELETE'
    }
}

$pair = "$MyDnsMasterId`:$MyDnsPassword"

$basic = [Convert]::ToBase64String(
    [Text.Encoding]::ASCII.GetBytes($pair)
)

$headers = @{
    Authorization = "Basic $basic"
}

$body = @{
    CERTBOT_DOMAIN     = $Identifier
    CERTBOT_VALIDATION = $Token
    EDIT_CMD           = $EditCmd
}

$response = Invoke-WebRequest `
    -Uri $MyDnsUrl `
    -Method Post `
    -Headers $headers `
    -ContentType 'application/x-www-form-urlencoded' `
    -Body $body `
    -UseBasicParsing `
    -ErrorAction Stop

$response.Content