From e6c8bbe9c6d4f6eaf51d17fd32d6c6052cce0140 Mon Sep 17 00:00:00 2001
From: Manuel Thalmann <m@nuth.ch>
Date: Tue, 27 Aug 2024 21:05:51 +0200
Subject: [PATCH] Add a script for managing backups

---
 scripts/Windows/Scripts/Restoration.ps1 | 119 ++++++++++++++++++++++++
 1 file changed, 119 insertions(+)
 create mode 100644 scripts/Windows/Scripts/Restoration.ps1

diff --git a/scripts/Windows/Scripts/Restoration.ps1 b/scripts/Windows/Scripts/Restoration.ps1
new file mode 100644
index 00000000..21c3ffc2
--- /dev/null
+++ b/scripts/Windows/Scripts/Restoration.ps1
@@ -0,0 +1,119 @@
+. "$PSScriptRoot/../../Common/Scripts/System.ps1";
+
+$null = New-Module {
+    $pathResolver = {
+        param(
+            [string] $User,
+            [string] $Path
+        )
+
+        [string] $result = $null;
+
+        if ($User) {
+            $result = "Users/$User";
+        } else {
+            $result = "System";
+        }
+
+        $result = Join-Path $result $Path;
+        return $result;
+    };
+
+    <#
+        .SYNOPSIS
+        Gets the name of the variable holding the path to the backup archive of the current machine.
+    #>
+    function Get-ArchiveVariableName {
+        return "BACKUP_ARCHIVE";
+    }
+
+    <#
+        .SYNOPSIS
+        Gets the path to the backup archive of the current machine.
+    #>
+    function Get-ValhallaBackupArchive {
+        (Get-Item "Env:\$(Get-ArchiveVariableName)").Value;
+    }
+
+    <#
+        .SYNOPSIS
+        Sets the path to the backup archive of the current machine.
+
+        .PARAMETER Path
+        The path to set.
+    #>
+    function Set-ValhallaBackupArchive {
+        param(
+            [string] $Path
+        )
+
+        Set-Item "Env:\$(Get-ArchiveVariableName)" $Path;
+    }
+
+    <#
+        .SYNOPSIS
+        Adds files to the backup archive.
+
+        .PARAMETER User
+        The user to add the files to.
+
+        .PARAMETER Source
+        The file or directory to add to the backup archive.
+
+        .PARAMETER Path
+        The path to the location to store the file or directory at.
+
+        .PARAMETER ArgumentList
+        The arguments to pass to the `7z` command.
+    #>
+    function Add-BackupArtifacts {
+        param(
+            [string] $User,
+            [string] $Source,
+            [string] $Path,
+            [Parameter(ValueFromRemainingArguments)]
+            [string[]] $ArgumentList
+        )
+
+        $dir = New-TemporaryDirectory;
+        $targetPath = & $pathResolver @PSBoundParameters;
+        $targetPath = Join-Path $dir $targetPath;
+        $null = New-Item -ItemType Directory -Force $targetPath;
+
+        Copy-Item -Force -Recurse $Source $targetPath;
+        7z a (Get-ValhallaBackupArchive) "$dir/*" @ArgumentList;
+        Remove-Item -Recurse -Force $dir;
+    }
+
+    <#
+        .SYNOPSIS
+        Extracts the specified backup artifacts to the specified target path.
+
+        .PARAMETER User
+        The user to restore the files for.
+
+        .PARAMETER Path
+        The path to restore the files from.
+
+        .PARAMETER Target
+        The path to restore the files to.
+
+        .PARAMETER ArgumentList
+        The arguments to pass to `7z`.
+    #>
+    function Expand-BackupArtifacts {
+        param(
+            [string] $User,
+            [string] $Path,
+            [string] $Target,
+            [Parameter(ValueFromRemainingArguments)]
+            [string[]] $ArgumentList
+        )
+
+        $dir = New-TemporaryDirectory;
+        $sourcePath = & $pathResolver @PSBoundParameters;
+        7z x "-o$dir" (Get-ValhallaBackupArchive) $sourcePath @ArgumentList;
+        Copy-Item -Recurse (Join-Path $dir $sourcePath) $Target;
+        Remove-Item -Recurse -Force $dir;
+    }
+};