# =========================
# Konfiguration
# =========================
$Server     = ".\KEYVI"
$Mode       = "Test"   # "Test" oder "Production"
$BackupFile = "D:\SQLBackup\DB_Keyvi\2026\07\DB_Keyvi_20260729_205555.bak"

$ProdDb = "DB_Keyvi"
$TestDb = "DB_Keyvi_RestoreTest"
# =========================

$ErrorActionPreference = "Stop"

if ($Mode -notin @("Test","Production")) {
    throw "Ungültiger Mode '$Mode'. Erlaubt: Test oder Production."
}
if (-not (Test-Path $BackupFile)) {
    throw "Backup-Datei nicht gefunden: $BackupFile"
}

$TargetDb = if ($Mode -eq "Production") { $ProdDb } else { $TestDb }

Write-Host "Modus: $Mode"
Write-Host "Server: $Server"
Write-Host "Ziel-Datenbank: $TargetDb"
Write-Host "Backup-Datei: $BackupFile"

if ($Mode -eq "Production") {
    Write-Warning "PRODUCTION-MODUS: Datenbank [$ProdDb] wird überschrieben!"
    $confirm = Read-Host "Tippe genau 'JA' zum Fortfahren"
    if ($confirm -ne "JA") { throw "Abgebrochen durch Benutzer." }
}

# Alles in SQL erledigen (robust, kein Text-Parsing nötig)
$sql = @"
USE [master];

DECLARE @BackupFile nvarchar(4000) = N'$BackupFile';
DECLARE @TargetDb   sysname        = N'$TargetDb';

DECLARE @DataPath nvarchar(4000) = CAST(SERVERPROPERTY('InstanceDefaultDataPath') AS nvarchar(4000));
DECLARE @LogPath  nvarchar(4000) = CAST(SERVERPROPERTY('InstanceDefaultLogPath')  AS nvarchar(4000));

IF @DataPath IS NULL OR @LogPath IS NULL
BEGIN
    RAISERROR(N'InstanceDefaultDataPath/LogPath konnte nicht ermittelt werden.',16,1);
    RETURN;
END

DECLARE @filelist TABLE (
    LogicalName           nvarchar(128),
    PhysicalName          nvarchar(260),
    [Type]                char(1),
    FileGroupName         nvarchar(128),
    [Size]                numeric(20,0),
    MaxSize               numeric(20,0),
    FileID                bigint,
    CreateLSN             numeric(25,0),
    DropLSN               numeric(25,0),
    UniqueID              uniqueidentifier,
    ReadOnlyLSN           numeric(25,0),
    ReadWriteLSN          numeric(25,0),
    BackupSizeInBytes     bigint,
    SourceBlockSize       int,
    FileGroupID           int,
    LogGroupGUID          uniqueidentifier,
    DifferentialBaseLSN   numeric(25,0),
    DifferentialBaseGUID  uniqueidentifier,
    IsReadOnly            bit,
    IsPresent             bit,
    TDEThumbprint         varbinary(32),
    SnapshotURL           nvarchar(360)
);

DECLARE @sqlFileList nvarchar(max) =
    N'RESTORE FILELISTONLY FROM DISK = N''' + REPLACE(@BackupFile,'''','''''') + N''';';

INSERT INTO @filelist
EXEC(@sqlFileList);

DECLARE @DataLogical sysname = (SELECT TOP(1) LogicalName FROM @filelist WHERE [Type]='D' ORDER BY FileID);
DECLARE @LogLogical  sysname = (SELECT TOP(1) LogicalName FROM @filelist WHERE [Type]='L' ORDER BY FileID);

IF @DataLogical IS NULL OR @LogLogical IS NULL
BEGIN
    RAISERROR(N'Konnte logische Daten-/Log-Datei im Backup nicht finden.',16,1);
    RETURN;
END

DECLARE @MdfTarget nvarchar(4000) = @DataPath + @TargetDb + N'.mdf';
DECLARE @LdfTarget nvarchar(4000) = @LogPath  + @TargetDb + N'_log.ldf';

IF DB_ID(@TargetDb) IS NOT NULL
BEGIN
    DECLARE @sqlSingle nvarchar(max) = N'ALTER DATABASE [' + @TargetDb + N'] SET SINGLE_USER WITH ROLLBACK IMMEDIATE;';
    EXEC(@sqlSingle);
END

DECLARE @sqlRestore nvarchar(max) = N'
RESTORE DATABASE [' + @TargetDb + N']
FROM DISK = N''' + REPLACE(@BackupFile,'''','''''') + N'''
WITH
    MOVE N''' + REPLACE(@DataLogical,'''','''''') + N''' TO N''' + REPLACE(@MdfTarget,'''','''''') + N''',
    MOVE N''' + REPLACE(@LogLogical, '''','''''') + N''' TO N''' + REPLACE(@LdfTarget, '''','''''') + N''',
    REPLACE,
    RECOVERY,
    STATS = 10;';

EXEC(@sqlRestore);

DECLARE @sqlMulti nvarchar(max) = N'ALTER DATABASE [' + @TargetDb + N'] SET MULTI_USER;';
EXEC(@sqlMulti);

PRINT N'Restore erfolgreich: ' + @TargetDb;
PRINT N'MDF: ' + @MdfTarget;
PRINT N'LDF: ' + @LdfTarget;
"@

sqlcmd -S $Server -E -C -b -Q $sql
if ($LASTEXITCODE -ne 0) {
    throw "Restore fehlgeschlagen (ExitCode $LASTEXITCODE)."
}

Write-Host "Fertig." -ForegroundColor Green