# Transfer Oracle INCREMENTAL Backup towards DR Server
# Rulează după backup incremental (14:30)
# Mai simplu decât scriptul full - doar transferă fișierele noi

param(
    [string]$SourceFRA = "C:\Users\Oracle\recovery_area\ROA",
    [string]$DRHost = "10.0.20.202",
    [int]$DRPort = 22,
    [string]$DRUser = "root",
    [string]$DRPath = "/mnt/pve/oracle-backups/ROA/autobackup",
    [string]$SSHKeyPath = "$env:USERPROFILE\.ssh\id_rsa",
    [string]$LogFile = "D:\rman_backup\logs\transfer_incr_$(Get-Date -Format 'yyyyMMdd_HHmm').log"
)

$ErrorActionPreference = "Continue"

function Write-Log {
    param([string]$Message, [string]$Level = "INFO")
    $timestamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
    $logLine = "[$timestamp] [$Level] $Message"
    Write-Host $logLine
    Add-Content -Path $LogFile -Value $logLine -Encoding UTF8 -ErrorAction SilentlyContinue
}

function Get-IncrementalBackups {
    Write-Log "Searching for incremental backup files created in last 2 hours..."

    $cutoffTime = (Get-Date).AddHours(-2)
    $backupFiles = @()

    # Caută în BACKUPSET, AUTOBACKUP
    $searchPaths = @(
        "$SourceFRA\BACKUPSET",
        "$SourceFRA\AUTOBACKUP"
    )

    foreach ($path in $searchPaths) {
        if (Test-Path $path) {
            $files = Get-ChildItem -Path $path -Recurse -File -ErrorAction SilentlyContinue |
                Where-Object {
                    $_.LastWriteTime -gt $cutoffTime -and
                    $_.Name -match '\.(BKP|bkp)$'
                }
            $backupFiles += $files
        }
    }

    return $backupFiles
}

function Cleanup-OldBackupsOnDR {
    param([int]$RetentionDays = 2)

    Write-Log "Cleaning up old backups on DR (keeping last $RetentionDays days)..."

    try {
        # Count fișiere înainte de cleanup
        $countBefore = & ssh -n -p $DRPort -i $SSHKeyPath "${DRUser}@${DRHost}" "find '$DRPath' -name '*.BKP' -type f | wc -l" 2>&1
        Write-Log "Backups before cleanup: $countBefore"

        # Cleanup: șterge fișiere mai vechi de $RetentionDays zile
        # -mtime +N înseamnă "mai vechi de N zile", deci pentru a păstra RetentionDays zile, folosim +($RetentionDays - 1)
        $mtimeDays = $RetentionDays - 1
        $cleanupCmd = "find '$DRPath' -name '*.BKP' -type f -mtime +$mtimeDays -delete 2>&1"
        $result = & ssh -n -p $DRPort -i $SSHKeyPath "${DRUser}@${DRHost}" $cleanupCmd 2>&1

        if ($LASTEXITCODE -ne 0) {
            Write-Log "Cleanup warning: $result" "WARNING"
        }

        # Count fișiere după cleanup
        $countAfter = & ssh -n -p $DRPort -i $SSHKeyPath "${DRUser}@${DRHost}" "find '$DRPath' -name '*.BKP' -type f | wc -l" 2>&1
        $deleted = [int]$countBefore - [int]$countAfter

        Write-Log "Cleanup completed: Deleted $deleted old backup files, $countAfter remaining"
    } catch {
        Write-Log "Cleanup error: $_" "WARNING"
    }
}

try {
    Write-Log "========================================="
    Write-Log "Oracle INCREMENTAL Backup Transfer Started"
    Write-Log "========================================="
    Write-Log "Source FRA: $SourceFRA"
    Write-Log "DR Server: $DRHost"

    # Test SSH connection
    Write-Log "Testing SSH connection to $DRHost`:$DRPort..."
    $null = & ssh -n -p $DRPort -i $SSHKeyPath -o StrictHostKeyChecking=no -o ConnectTimeout=10 "${DRUser}@${DRHost}" "exit 0" 2>&1
    if ($LASTEXITCODE -ne 0) {
        throw "SSH connection failed"
    }
    Write-Log "SSH connection OK" "SUCCESS"

    # Găsește backup-uri incrementale
    $backupFiles = Get-IncrementalBackups

    if ($backupFiles.Count -eq 0) {
        Write-Log "⚠️  No incremental backup files found (this might be normal if backup didn't run yet)" "WARNING"
        exit 0
    }

    $totalSizeGB = ($backupFiles | Measure-Object -Property Length -Sum).Sum / 1GB
    Write-Log "Found $($backupFiles.Count) incremental files, total size: $([math]::Round($totalSizeGB, 2)) GB"

    # Transfer fișiere
    Write-Log "Starting file transfer..."
    $successCount = 0
    $failCount = 0

    foreach ($file in $backupFiles) {
        $fileName = $file.Name
        $fileSizeMB = [math]::Round($file.Length / 1MB, 2)

        # Check dacă fișierul există deja pe DR (skip duplicates) - Linux bash command
        $checkCmd = "test -f '$DRPath/$fileName' && echo 'True' || echo 'False'"
        $checkResult = & ssh -n -p $DRPort -i $SSHKeyPath "${DRUser}@${DRHost}" $checkCmd 2>&1

        if ($checkResult -match "True") {
            Write-Log "Skipping (already on DR): $fileName" "INFO"
            $successCount++
            continue
        }

        Write-Log "Transferring: $fileName ($fileSizeMB MB)"

        # SCP optimized: no compression (already compressed), fast cipher
        $null = & scp -P $DRPort -i $SSHKeyPath -o StrictHostKeyChecking=no -o Compression=no -o Cipher=aes128-gcm@openssh.com `
            $file.FullName `
            "${DRUser}@${DRHost}:${DRPath}/$fileName" 2>&1

        if ($LASTEXITCODE -eq 0) {
            Write-Log "Transferred: $fileName" "SUCCESS"
            $successCount++
        } else {
            Write-Log "Failed to transfer: $fileName" "ERROR"
            $failCount++
        }
    }

    Write-Log "========================================="
    Write-Log "Transfer summary: $successCount succeeded, $failCount failed"

    if ($failCount -gt 0) {
        Write-Log "⚠️  Some transfers failed!" "WARNING"
        exit 1
    }

    # Cleanup old backups pe DR (keep last 2 days)
    Cleanup-OldBackupsOnDR -RetentionDays 2

    Write-Log "========================================="
    Write-Log "INCREMENTAL Backup Transfer Completed Successfully"
    Write-Log "========================================="
    Write-Log "Files transferred: $successCount/$($backupFiles.Count)"

    exit 0

} catch {
    Write-Log "CRITICAL ERROR: $($_.Exception.Message)" "ERROR"
    exit 1
}