$ErrorActionPreference = 'Stop'
$url = 'http://127.0.0.1:8000/'
$serverOutput = Join-Path $env:TEMP 'r2c-viewer-server.log'
$serverError = Join-Path $env:TEMP 'r2c-viewer-server-error.log'

function Test-Viewer {
    try {
        $model = Invoke-RestMethod -Uri ($url + 'model.json') -TimeoutSec 10
        return ($null -ne $model.meshes -and $null -ne $model.variants)
    } catch { return $false }
}

try {
    if (-not (Test-Viewer)) {
        # Explorer exposes WSL folders as either of these UNC paths.
        if ($PSScriptRoot -match '^\\\\(?:wsl\$|wsl\.localhost)\\([^\\]+)\\(.*)$') {
            $distro = $Matches[1]
            $linuxPath = '/' + $Matches[2].Replace('\', '/')
            $wslArgs = @('-d', $distro, '--cd', ('"' + $linuxPath + '"'), '--', 'python3', 'r2c.py', 'serve')
        } else {
            $linuxPath = & wsl.exe -- wslpath -u $PSScriptRoot
            if ($LASTEXITCODE -ne 0) { throw 'Cannot locate the project in WSL.' }
            $wslArgs = @('--cd', ('"' + $linuxPath.Trim() + '"'), '--', 'python3', 'r2c.py', 'serve')
        }
        $server = Start-Process -FilePath 'wsl.exe' -ArgumentList $wslArgs -PassThru -RedirectStandardOutput $serverOutput -RedirectStandardError $serverError
        $ready = $false
        for ($attempt = 0; $attempt -lt 30; $attempt++) {
            if (Test-Viewer) { $ready = $true; break }
            if ($server.HasExited) {
                $details = Get-Content $serverError -Raw -ErrorAction SilentlyContinue
                throw ('The viewer server exited: ' + $details)
            }
            Start-Sleep -Milliseconds 500
        }
        if (-not $ready) { throw 'The viewer did not respond at http://localhost:8000/. Check WSL and port 8000.' }
    }
    Start-Process $url
} catch {
    Write-Host $_.Exception.Message -ForegroundColor Red
    exit 1
}