<#
.SYNOPSIS
    Minimal WebDAV server for testing deploy-generator.ps1 without a real host.

.DESCRIPTION
    Serves files under -Root at http://localhost:<Port>/, requiring Basic
    authentication with -User/-Pass.  Supports GET, PUT, DELETE, COPY and MOVE
    (with the Destination and Overwrite headers) - the subset the deploy
    script uses.  Every authenticated request's method and path is appended
    to -LogFile so tests can assert on the exact sequence.

    GET requests under /public/ need no authentication, standing in for the
    public web server.  Requesting /__shutdown stops the server.

    If a file named .mock-cpanel exists in -Root, successful COPY and MOVE
    answer 200 instead of 201/204, as cPanel's Web Disk (cpdavd) does.
#>
param(
    [Parameter(Mandatory)] [int]    $Port,
    [Parameter(Mandatory)] [string] $Root,
    [Parameter(Mandatory)] [string] $User,
    [Parameter(Mandatory)] [string] $Pass,
    [Parameter(Mandatory)] [string] $LogFile
)

$ErrorActionPreference = 'Stop'
$expected = 'Basic ' + [Convert]::ToBase64String([Text.Encoding]::UTF8.GetBytes("${User}:${Pass}"))

$listener = New-Object System.Net.HttpListener
$listener.Prefixes.Add("http://localhost:$Port/")
$listener.Start()

<#
.SYNOPSIS  Maps a request path (or absolute Destination URL) to a file under Root.
#>
function Resolve-Local([string] $UrlOrPath) {
    $path = if ($UrlOrPath -match '^[a-z]+://') { ([Uri]$UrlOrPath).AbsolutePath } else { $UrlOrPath }
    $rel = [Uri]::UnescapeDataString($path).TrimStart('/').Replace('/', '\')
    return Join-Path $Root $rel
}

try {
    while ($listener.IsListening) {
        $ctx = $listener.GetContext()
        $req = $ctx.Request
        $res = $ctx.Response
        try {
            if ($req.Url.AbsolutePath -eq '/__shutdown') {
                $res.StatusCode = 200
                $res.Close()
                break
            }

            # /public/ stands in for the web server: readable without credentials.
            $isPublic = $req.HttpMethod -eq 'GET' -and $req.Url.AbsolutePath.StartsWith('/public/')
            if (-not $isPublic -and $req.Headers['Authorization'] -ne $expected) {
                $res.StatusCode = 401
                $res.AddHeader('WWW-Authenticate', 'Basic realm="mock"')
                continue
            }

            Add-Content -LiteralPath $LogFile -Value ("{0} {1}" -f $req.HttpMethod, [Uri]::UnescapeDataString($req.Url.AbsolutePath))
            $file = Resolve-Local $req.Url.AbsolutePath

            switch ($req.HttpMethod) {
                'GET' {
                    if (Test-Path -LiteralPath $file -PathType Leaf) {
                        $bytes = [IO.File]::ReadAllBytes($file)
                        $res.StatusCode = 200
                        $res.OutputStream.Write($bytes, 0, $bytes.Length)
                    } else {
                        $res.StatusCode = 404
                    }
                }
                'PUT' {
                    $ms = New-Object IO.MemoryStream
                    $req.InputStream.CopyTo($ms)
                    $existed = Test-Path -LiteralPath $file -PathType Leaf
                    New-Item -ItemType Directory -Force -Path (Split-Path $file) | Out-Null
                    [IO.File]::WriteAllBytes($file, $ms.ToArray())
                    $res.StatusCode = if ($existed) { 204 } else { 201 }
                }
                'DELETE' {
                    if (Test-Path -LiteralPath $file -PathType Leaf) {
                        Remove-Item -LiteralPath $file
                        $res.StatusCode = 204
                    } else {
                        $res.StatusCode = 404
                    }
                }
                { $_ -in 'COPY', 'MOVE' } {
                    $destHeader = $req.Headers['Destination']
                    if (-not $destHeader) { $res.StatusCode = 400; break }
                    $dest = Resolve-Local $destHeader
                    $overwrite = $req.Headers['Overwrite'] -ne 'F'
                    if (-not (Test-Path -LiteralPath $file -PathType Leaf)) { $res.StatusCode = 404; break }
                    $existed = Test-Path -LiteralPath $dest -PathType Leaf
                    if ($existed -and -not $overwrite) { $res.StatusCode = 412; break }
                    New-Item -ItemType Directory -Force -Path (Split-Path $dest) | Out-Null
                    if ($req.HttpMethod -eq 'COPY') {
                        Copy-Item -LiteralPath $file -Destination $dest -Force
                    } else {
                        Move-Item -LiteralPath $file -Destination $dest -Force
                    }
                    $res.StatusCode = if ($existed) { 204 } else { 201 }
                    # cPanel's cpdavd answers a successful COPY/MOVE with 200;
                    # a test opts into that by creating .mock-cpanel in Root.
                    if (Test-Path -LiteralPath (Join-Path $Root '.mock-cpanel')) { $res.StatusCode = 200 }
                }
                default { $res.StatusCode = 405 }
            }
        } finally {
            try { $res.Close() } catch { }
        }
    }
} finally {
    $listener.Stop()
    $listener.Close()
}