#Requires -Version 5.1
param(
    [Parameter(Mandatory=$true)][ValidateSet('export','restore')][string]$Mode,
    [Parameter(Mandatory=$true)][string]$Path,
    [string]$EnvPath = (Join-Path (Split-Path -Parent $PSScriptRoot) '.env')
)
$ErrorActionPreference = 'Stop'
. (Join-Path $PSScriptRoot 'Initialize-SecurityEnv.ps1')
function Protect-CredentialFile([string]$FilePath) {
    if ($env:OS -eq 'Windows_NT') {
        $sid = [System.Security.Principal.WindowsIdentity]::GetCurrent().User
        $acl = New-Object System.Security.AccessControl.FileSecurity
        $acl.SetAccessRuleProtection($true, $false)
        $acl.AddAccessRule((New-Object System.Security.AccessControl.FileSystemAccessRule($sid, 'FullControl', 'Allow')))
        Set-Acl -LiteralPath $FilePath -AclObject $acl
    } else { & chmod 600 $FilePath; if ($LASTEXITCODE) { throw 'Cannot protect credential file' } }
}
if (-not (Test-Path -LiteralPath $EnvPath -PathType Leaf)) { throw 'Prepare the deployment .env first' }
$EnvPath = [System.IO.Path]::GetFullPath($EnvPath)
$Path = [System.IO.Path]::GetFullPath($Path)
if ($EnvPath -eq $Path) { throw 'Keep the key backup separate from deployment configuration' }
$source = $EnvPath
if ($Mode -eq 'restore') { $source = $Path }
$content = Get-Content -LiteralPath $source -Raw -Encoding UTF8
$active = Get-EnvValue $content 'CONFIG_CREDENTIAL_ENCRYPTION_ACTIVE_KEY_ID'
$ring = Get-EnvValue $content 'CONFIG_CREDENTIAL_ENCRYPTION_KEYRING'
$legacy = Get-EnvValue $content 'CONFIG_CREDENTIAL_ALLOW_LEGACY_PLAINTEXT'
if (-not $active -or -not $ring) { throw 'Incomplete original keyring; no replacement key will be generated' }
if (-not $legacy) { $legacy = 'false' }
$keyContent = "CONFIG_CREDENTIAL_ENCRYPTION_ACTIVE_KEY_ID=$active`nCONFIG_CREDENTIAL_ENCRYPTION_KEYRING='$ring'`nCONFIG_CREDENTIAL_ALLOW_LEGACY_PLAINTEXT=$legacy`n"
foreach ($name in @('CONFIG_SECURITY_CONFIG_ENCRYPTION_KEY','CONFIG_JWT_SECRET')) {
    $match = [regex]::Match($content, "(?m)^$name=(.*)$")
    if ($match.Success) { $keyContent += $match.Value.TrimEnd("`r") + "`n" }
    elseif ($Mode -eq 'export') { $keyContent += "$name=`n" }
}
$tmp = $EnvPath + '.credential-keys.' + [Guid]::NewGuid().ToString('N')
try {
    [System.IO.File]::WriteAllText($tmp, '', (New-Object System.Text.UTF8Encoding($false)))
    Protect-CredentialFile $tmp
    [System.IO.File]::WriteAllText($tmp, $keyContent, (New-Object System.Text.UTF8Encoding($false)))
    Initialize-SecurityEnv -Path $tmp -Mode upgrade *> $null
    if ($Mode -eq 'export') {
        $reservation = [System.IO.File]::Open($Path, 'CreateNew', 'Write', 'None'); $reservation.Dispose()
        Protect-CredentialFile $Path
        [System.IO.File]::WriteAllText($Path, $keyContent, (New-Object System.Text.UTF8Encoding($false)))
        Write-Host 'Exported full keyring, including old keys. Store privately and separately from database backups.'
    } else {
        $original = Get-Content -LiteralPath $EnvPath -Raw -Encoding UTF8
        $previous = $EnvPath + '.pre-credential-restore.' + [Guid]::NewGuid().ToString('N')
        [System.IO.File]::WriteAllText($previous, '', (New-Object System.Text.UTF8Encoding($false)))
        Protect-CredentialFile $previous
        [System.IO.File]::WriteAllText($previous, $original, (New-Object System.Text.UTF8Encoding($false)))
        foreach ($name in @('CONFIG_CREDENTIAL_ENCRYPTION_ACTIVE_KEY_ID','CONFIG_CREDENTIAL_ENCRYPTION_KEYRING','CONFIG_CREDENTIAL_ALLOW_LEGACY_PLAINTEXT','CONFIG_SECURITY_CONFIG_ENCRYPTION_KEY','CONFIG_JWT_SECRET')) {
            $saved = [regex]::Match($keyContent, "(?m)^$name=(.*)$")
            if (-not $saved.Success) { continue }
            $literalLine = $saved.Value.TrimEnd("`r") + "`r`n"
            $pattern = "(?m)^$name=.*(?:\r?\n)?"
            if ([regex]::IsMatch($original, $pattern)) {
                $evaluator = [System.Text.RegularExpressions.MatchEvaluator]{ param($match) return $literalLine }.GetNewClosure()
                $original = [regex]::Replace($original, $pattern, $evaluator)
            } else { $original = $original.TrimEnd("`r","`n") + "`r`n" + $literalLine }
        }
        [System.IO.File]::WriteAllText($tmp, $original, (New-Object System.Text.UTF8Encoding($false)))
        Move-Item -LiteralPath $tmp -Destination $EnvPath -Force
        Protect-CredentialFile $EnvPath
        Write-Host 'Restored original keyring; other configuration preserved. Recreate all related containers before database restore.'
    }
} finally { if (Test-Path -LiteralPath $tmp) { Remove-Item -LiteralPath $tmp -Force } }