# requires -version 5.1
# verify_kb_nonregression_v1.0.ps1
# Lecture-seule : vérifie que la KB du ZIP ne réduit pas le nombre d'entrées
# ni ne supprime d'IDs sans ALLOW_PURGE__CONFIRM.txt (opt-in explicite).
# ASCII-only; UTF-8 BOM; no here-strings; no ternary.
param(
  [Parameter(Mandatory=$true)][string]$Root,
  [Parameter(Mandatory=$true)][string]$ZipPath
)

function Ensure-Dir([string]$Path) { if(-not (Test-Path -LiteralPath $Path)) { New-Item -ItemType Directory -Path $Path | Out-Null } }
function Read-All([string]$Path) { Get-Content -LiteralPath $Path -Raw }

# ---- Self-check (PS5.1) ----
$__scriptPath = $MyInvocation.MyCommand.Definition
$__src = Read-All -Path $__scriptPath
$__noComments = [regex]::Replace($__src, '(?m)#.*$', '')
$__masked = [regex]::Replace($__noComments, "('[^']*')", "''")
$__masked = [regex]::Replace($__masked, '("(?:[^"`]|`".)*")', '""')
if($__masked -match '\?\s*:'){
  Write-Host "[FAIL] STYLE_GUARD_PS51: opérateur ternaire détecté dans ce script." -ForegroundColor Red
  exit 2
}

if(-not (Test-Path -LiteralPath $ZipPath)){ Write-Host "[FAIL] ZIP introuvable: $ZipPath" -ForegroundColor Red; exit 2 }

$kbCurrent = Join-Path $Root 'bug_kb\BUG_KB.json.txt'
if(-not (Test-Path -LiteralPath $kbCurrent)){
  Write-Host "[FAIL] KB actuelle absente: $kbCurrent" -ForegroundColor Red
  exit 2
}

# Unpack temporaire
$un = "C:\Temp_Gouvernance\_verify_nonreg"
Ensure-Dir -Path $un
$tag = Get-Date -Format "yyyyMMdd_HHmmss"
$dest = Join-Path $un ("_unpack_" + $tag)
Expand-Archive -LiteralPath $ZipPath -DestinationPath $dest -Force

# Cherche fichier KB proposé
$kbProposed = $null
Get-ChildItem -LiteralPath $dest -File | ForEach-Object {
  if($_.Name -match '^BUG_KB__canonical_.*\.json\.txt$'){ $script:kbProposed = $_.FullName }
}

if($null -eq $kbProposed){
  Write-Host "[FAIL] Aucun fichier BUG_KB__canonical_*.json.txt trouvé dans le ZIP." -ForegroundColor Red
  exit 2
}

# ALLOW_PURGE opt-in
$allowPurge = $false
if(Test-Path -LiteralPath (Join-Path $dest 'ALLOW_PURGE__CONFIRM.txt')){ $allowPurge = $true }

# Parse IDs
function Get-IdSet([string]$Path){
  $ids = New-Object System.Collections.Generic.HashSet[string]
  Get-Content -LiteralPath $Path | ForEach-Object {
    $t = $_.Trim()
    if($t -match '^\{.*\}\s*$'){
      try{
        $o = $t | ConvertFrom-Json
        $id = ""
        if($o.PSObject.Properties.Name -contains 'id'){ $id = [string]$o.id }
        if([string]::IsNullOrWhiteSpace($id)){ $id = "" }
        if($id -ne ""){ [void]$ids.Add($id) }
      } catch {}
    }
  }
  return $ids
}

$currentIds  = Get-IdSet -Path $kbCurrent
$proposedIds = Get-IdSet -Path $kbProposed

$currentCount  = $currentIds.Count
$proposedCount = $proposedIds.Count

# Diff sets
$removed = New-Object System.Collections.Generic.List[string]
$added   = New-Object System.Collections.Generic.List[string]

foreach($id in $currentIds){ if(-not $proposedIds.Contains($id)){ $removed.Add($id) } }
foreach($id in $proposedIds){ if(-not $currentIds.Contains($id)){ $added.Add($id) } }

$fail = $false
$reasons = @()

if($proposedCount -lt $currentCount){
  $fail = $true
  $reasons += "[COUNT] proposed < current (" + $proposedCount + " < " + $currentCount + ")"
}
if(($removed.Count -gt 0) -and (-not $allowPurge)){
  $fail = $true
  $reasons += "[REMOVED IDs] " + $removed.Count + " (pas d'ALLOW_PURGE__CONFIRM.txt)"
}

Write-Host "================ NON-REGRESSION CHECK ================"
Write-Host ("ZIP        : " + $ZipPath)
Write-Host ("KB current : " + $kbCurrent)
Write-Host ("Current IDs: " + $currentCount)
Write-Host ("Proposed IDs: " + $proposedCount)
Write-Host ("Added IDs  : " + $added.Count)
Write-Host ("Removed IDs: " + $removed.Count)
if($removed.Count -gt 0){ 
  Write-Host "REMOVED LIST (max 20):"
  $i = 0
  foreach($id in $removed){
    Write-Host (" - " + $id)
    $i = $i + 1
    if($i -ge 20){ break }
  }
}
if($allowPurge){ Write-Host "[NOTICE] ALLOW_PURGE__CONFIRM.txt présent dans le ZIP — suppression d'IDs autorisée." }

if($fail){
  Write-Host "RESULT : [FAIL]" -ForegroundColor Red
  Write-Host "REASONS:"
  foreach($r in $reasons){ Write-Host (" - " + $r) }
  exit 2
} else {
  Write-Host "RESULT : [PASS]"
  exit 0
}