$ErrorActionPreference = 'Stop'
$script:failed = 0

function Assert-True($cond, $msg) {
    if ($cond) { Write-Host "PASS: $msg" }
    else { Write-Host "FAIL: $msg"; $script:failed++ }
}

Write-Host "=== environment ==="
Write-Host "host=$env:COMPUTERNAME user=$env:USERNAME"
Write-Host "ps=$($PSVersionTable.PSVersion)"

Write-Host "=== tests ==="
Assert-True ($PSVersionTable.PSVersion.Major -ge 5) "PowerShell major >= 5"
Assert-True ((Get-CimInstance Win32_OperatingSystem).Caption -match 'Windows') "OS reports as Windows"
Assert-True ((2 + 2) -eq 4) "arithmetic sanity"
Assert-True ($env:USERNAME -eq 'edr') "running as edr"

$tmp = Join-Path $env:TEMP "ci-write-test.txt"
"hello $(Get-Date -Format o)" | Out-File -Encoding ascii $tmp
Assert-True (Test-Path $tmp) "wrote file under TEMP"
Assert-True ((Get-Content $tmp) -match 'hello') "read file content back"
Remove-Item $tmp -Force

if ($failed -gt 0) {
    Write-Host "$failed test(s) failed"
    exit 1
}
Write-Host "all tests passed"
exit 0