# DeployCenter - asynchronous Gitea release check
# Compatible with Windows PowerShell 5.1

function ConvertTo-DeployCenterComparableVersion {
    [CmdletBinding()]
    param([Parameter(Mandatory=$true)][string]$VersionText)

    if ($VersionText -notmatch '(?i)(?:^|[-_])v?(?<Numeric>\d+(?:\.\d+){1,3})(?=$|[-+])') {
        return $null
    }
    $parts = @($Matches.Numeric.Split('.'))
    while ($parts.Count -lt 4) { $parts += '0' }
    try { return [version]::Parse(($parts -join '.')) } catch { return $null }
}

function Start-DeployCenterVersionCheck {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)][string]$CurrentVersion,
        [Parameter(Mandatory=$true)][string]$ReleaseApiUrl
    )

    try {
        [System.Net.ServicePointManager]::SecurityProtocol =
            [System.Net.ServicePointManager]::SecurityProtocol -bor [System.Net.SecurityProtocolType]::Tls12
        $request = [System.Net.HttpWebRequest]::Create($ReleaseApiUrl)
        $request.Method = 'GET'
        $request.Accept = 'application/json'
        $request.UserAgent = 'DeployCenter-VersionCheck/1.0'
        $request.Timeout = 4000
        $request.ReadWriteTimeout = 4000
        $request.KeepAlive = $false
        $asyncResult = $request.BeginGetResponse($null, $null)
        return [pscustomobject]@{
            CurrentVersion = $CurrentVersion
            Request = $request
            AsyncResult = $asyncResult
            Completed = $false
            Update = $null
        }
    } catch {
        # This optional check must never interrupt startup or deployment.
        return $null
    }
}

function Complete-DeployCenterVersionCheck {
    [CmdletBinding()]
    param([Parameter(Mandatory=$true)]$Check)

    if ($Check.Completed -or -not $Check.AsyncResult.IsCompleted) { return $null }
    $Check.Completed = $true
    $response = $null
    $reader = $null
    try {
        $response = [System.Net.HttpWebResponse]$Check.Request.EndGetResponse($Check.AsyncResult)
        if ([int]$response.StatusCode -ne 200) { return $null }
        $reader = New-Object System.IO.StreamReader($response.GetResponseStream())
        $release = ConvertFrom-Json -InputObject $reader.ReadToEnd() -ErrorAction Stop
        if ($release.draft -or [string]::IsNullOrWhiteSpace([string]$release.tag_name)) { return $null }
        $current = ConvertTo-DeployCenterComparableVersion -VersionText ([string]$Check.CurrentVersion)
        $latest = ConvertTo-DeployCenterComparableVersion -VersionText ([string]$release.tag_name)
        if ($null -eq $current -or $null -eq $latest -or $latest -le $current) { return $null }
        $Check.Update = [pscustomobject]@{
            CurrentVersion = [string]$Check.CurrentVersion
            LatestVersion = [string]$release.tag_name
        }
        return $Check.Update
    } catch {
        # A network/API failure simply leaves the local version visible.
        return $null
    } finally {
        if ($null -ne $reader) { $reader.Dispose() }
        if ($null -ne $response) { $response.Dispose() }
    }
}

Export-ModuleMember -Function Start-DeployCenterVersionCheck, Complete-DeployCenterVersionCheck