PSComputerManagementZp

0.1.3

Public/Classes/FormattedFileSystemPath.ps1

class FormattedFileSystemPath {
<#
.SYNOPSIS
    A class that receives a file system path, formats the path automatically when initialized, holds the formatted path, and provides some useful attributes(properties) simultaneously for a quick check.

.DESCRIPTION
    Automatically format a path to standard format by the following procedures and rules:
    **First**: Preprocess a received path with some literal check (string level, without accessing it by file system):
        - Check:
            - Check if it contains wildcard characters `*`, `?` or `[]`. If so, throw an error.
            - Check if it contains more than 1 group of consecutive colons. If so, throw an error.
        - Normalize at a preliminary level:
            - Reduce any consecutive colons to a single `:`
            - Strip any trailing slashs.
            - According to the platform, append a single `\` or `/` if the path ends with a colon.
            - Convert all slashes to `\` or `/`, according to the platform.
        - Define the following three path types
            - Absolute path:
                On Windows: A path that contains a colon `:` and with a letter in the range `A-Z` or `a-z` at the beginning, i.g., `C:\Users\User\test.txt`.
                On Unix: A path that starts with a slash `/`.
            - Relative path:
                On Windows: A path that does not contain any colon and does not start with a slash `\`.
                On Unix: A path that does not start with a slash `/`.
            - Universal Naming Convention (UNC) path (network path):
                On Windows: A path that does not contain any colon and does start with a double slash `\\`.
                On Unix: A path that starts with a double slash `//`.
            - If no matched path type, throw an error.
        - Normalize at a deeper level:
            - Reduce any consecutive slashes to a single one.
                - If is absolute path, convert the drive name to initial capital letter.
                - If is UNC path, add a slash (according to the platform) to the beginning to meet `double slashes`.
                - If is relative path, add a dot with a slash (according to the platform) to the beginning.

    **Second**: Test the preprocessed path with file system access:
        - Check if the path exists in file system. If not, throw an error.
        - Check if the path is with wildcard characters by file system. If so, throw an error.
            - It means a path (an instance of this class) represents only a path, not a group of paths.

    **Third** Format the path with file system access:
        - Convert it to an absolute one.
        - Convert it to an original-case one.
            - Even though, by [default](https://learn.microsoft.com/zh-cn/windows/wsl/case-sensitivity), items in NTFS of Windows is not case-sensitive, but actually it has the ability to be case-sensitive.
            - And, in NTFS of Windows, two paths with only case differences can represent the same item, i.g., `c:\uSeRs\usER\TesT.tXt` and `C:\Users\User\test.txt`.
            - Furthermore, by `explorer.exe`, we can see that the original case of a path. If we change its case, the original case will be changed too.
            - So, NTFS does save and maintain the original case of a path. It just be intentionally case-insensitive rather than incapable of being case-sensitive.
            - This class use the methods [here](https://stackoverflow.com/q/76982195/17357963) to get the original case of a path, then maintian it.

    **#TODO **:
        - Cross-platform support.
        - Currently, this class is only adapative on each single platform, but not cross-platform.
        - But for preliminary process, the source's platform will be detected and recorded in the property `OriginalPlatform`.

    **Some properties of the path are also provided**:
        1. LiteralPath: The formatted path.
        2. OriginalPlatform: The platform of the source path.
        3. Slash: The slash of the path.
        4. Attributes: The attributes of the path.
        5. Linktype: The link type of the path.
        6. LinkTarget: The link target of the path.
        7. Qualifier: The qualifier of the path.
        8. QualifierRoot: The root of the qualifier of the path.
        9. DriveFormat: The format of the drive of the path.
        10. IsDir: If the path is a directory.
        11. IsFile: If the path is a file.
        12. IsDriveRoot: If the path is the root of a drive.
        13. IsBeOrInSystemDrive: If the path is in the system drive.
        14. IsInHome: If the path is in the home directory.
        15. IsHome: If the path is the home directory.
        16. IsDesktopINI: If the path is a desktop.ini file.
        (Windows only):
            17. IsSystemVolumeInfo: If the path is the System Volume Information directory.
            18. IsInSystemVolumeInfo: If the path is in the System Volume Information directory.
            19. IsRecycleBin: If the path is the Recycle Bin directory.
        20. IsInRecycleBin: If the path is in the Recycle Bin directory.
        21. IsSymbolicLink: If the path is a symbolic link.
        22. IsJunction: If the path is a junction.
        23. IsHardLink: If the path is a hard link.

.EXAMPLE
    Not usage examples, but a demonstration about the path formatting:

    | (Windows) Existing Path | Given(Input) Path | Formatted Path |
    | ------------------------- | ------------------------- | ----------------- |
    | C:\Users | c:\uSeRs | C:\Users\ |
    | C:\Users | C:\uSers | C:\Users\ |
    | C:\Users\test.txt | c:\uSeRs\usER\TesT.tXt | C:\Users\test.txt |
    | C:\Users\test.txt | C:\uSeRs\user\TEST.TxT | C:\Users\test.txt |

    | (Unix) Existing Path | Given(Input) Path | Formatted Path |
    | ------------------------- | ------------------------- | ----------------- |
    | /home/uSer | /home/uSer | /home/uSer/ |
.PARAMETER Path
    The path to be formatted.
.INPUTS
    String.
.OUTPUTS
    FormattedFileSystemPath.
.NOTES
    Support file system paths only!
.LINK
    [Default case-sensitive](https://learn.microsoft.com/zh-cn/windows/wsl/case-sensitivity).
    [Fromatting methods](https://stackoverflow.com/q/76982195/17357963).
#>
    [ValidateNotNullOrEmpty()][string] $LiteralPath
    [ValidateNotNullOrEmpty()][string] $OriginalPlatform
    [ValidateSet('\','/')][string] $Slash
    [AllowNull()][string] $Attributes
    [AllowNull()][string] $Linktype = $null
    [AllowNull()][string] $LinkTarget = $null
    [AllowNull()][string] $Qualifier
    [AllowNull()][string] $QualifierRoot
    [AllowNull()][string] $DriveFormat
    [ValidateNotNullOrEmpty()][bool] $IsDir
    [ValidateNotNullOrEmpty()][bool] $IsFile
    [ValidateNotNullOrEmpty()][bool] $IsDriveRoot
    [ValidateNotNullOrEmpty()][bool] $IsBeOrInSystemDrive
    [ValidateNotNullOrEmpty()][bool] $IsInHome
    [ValidateNotNullOrEmpty()][bool] $IsHome
    [Nullable[bool]] $IsDesktopINI = $null
    [Nullable[bool]] $IsSystemVolumeInfo = $null
    [Nullable[bool]] $IsInSystemVolumeInfo = $null
    [Nullable[bool]] $IsRecycleBin = $null
    [Nullable[bool]] $IsInRecycleBin = $null
    [ValidateNotNullOrEmpty()][bool] $IsSymbolicLink
    [ValidateNotNullOrEmpty()][bool] $IsJunction
    [ValidateNotNullOrEmpty()][bool] $IsHardLink

    FormattedFileSystemPath([string] $Path) {
        if ([Environment]::OSVersion.Platform -eq "Win32NT"){
            $this.OriginalPlatform = "Win32NT"
            $this.Slash = '\'
        }elseif ([Environment]::OSVersion.Platform -eq "Unix") {
            $this.OriginalPlatform = "Unix"
            $this.Slash = '/'
        }else{
            throw "Only Win32NT and Unix are supported, not $($global:PSVersionTable.Platform)."
        }

        $Path = $this.PreProcess($Path)

        if(!(Test-Path -LiteralPath $Path)){
            throw (New-Object System.Management.Automation.ItemNotFoundException "Path '$Path' not found.")
        }
        if ($this.GetQualifier($Path).Provider.Name -notin @('FileSystem',$null)){
            throw "Only paths in FileSystem provider or UNC are supported, not $($this.GetQualifier($Path).Provider.Name)."
        }
        $this.LiteralPath = $this.FormatPath($Path)
        $this.Attributes = (Get-ItemProperty $this.LiteralPath).Attributes
        $this.Linktype = (Get-ItemProperty $this.LiteralPath).Linktype

        $link_target = (Get-ItemProperty $this.LiteralPath).LinkTarget
        if ($link_target){
            $link_target = $this.PreProcess($link_target)
            $this.LinkTarget = $this.FormatPath($link_target)
        }else{
            $this.LinkTarget = $link_target
        }
        $this.Qualifier = $this.GetQualifier($this.LiteralPath).Name
        $this.QualifierRoot = $this.GetQualifier($this.LiteralPath).Root
        $this.DriveFormat = ([System.IO.DriveInfo]::GetDrives() | Where-Object {$_.RootDirectory.FullName -eq $this.QualifierRoot}).DriveFormat

        if (Test-Path -LiteralPath $this.LiteralPath -PathType Container){
            $this.IsDir = $true
            $this.IsFile = $false
        }
        else {
            $this.IsDir = $false
            $this.IsFile = $true
        }

        if ($this.LiteralPath -eq $this.QualifierRoot){
            $this.IsDriveRoot = $true
        }
        else {
            $this.IsDriveRoot = $false
        }

        $home_path = $this.FormatPath([Environment]::GetFolderPath("UserProfile"))
        if ($this.Qualifier -eq $this.GetQualifier($home_path).Name){
            $this.IsBeOrInSystemDrive = $true
        }
        else {
            $this.IsBeOrInSystemDrive = $false
        }
        if ($this.LiteralPath.StartsWith($home_path)){
            if ($this.LiteralPath.EndsWith($home_path)){
                $this.IsHome = $true
                $this.IsInHome = $false
            }else{
                $this.IsHome = $false
                $this.IsInHome = $true
            }
        }else{
            $this.IsHome = $false
            $this.IsInHome = $false
        }

        if ($this.OriginalPlatform -eq "Win32NT"){
            if ($this.IsFile -and ((Split-Path $this.LiteralPath -Leaf) -eq "desktop.ini")){
                $this.IsDesktopINI = $true
            }
            else {
                $this.IsDesktopINI = $false
            }
            $system_volume_information_path = $this.FormatPath("$($this.QualifierRoot)System Volume Information")
            if ($this.LiteralPath.StartsWith($system_volume_information_path)){
                if ($this.LiteralPath.EndsWith($system_volume_information_path)){
                    $this.IsSystemVolumeInfo = $true
                    $this.IsInSystemVolumeInfo = $false
                }else{
                    $this.IsSystemVolumeInfo = $false
                    $this.IsInSystemVolumeInfo = $true
                }
            }else{
                $this.IsSystemVolumeInfo = $false
                $this.IsInSystemVolumeInfo = $false
            }

            $recycle_bin_path = $this.FormatPath("$($this.QualifierRoot)`$RECYCLE.BIN")
            if ($this.LiteralPath.StartsWith($recycle_bin_path)){
                if ($this.LiteralPath.EndsWith($recycle_bin_path)){
                    $this.IsRecycleBin = $true
                    $this.IsInRecycleBin = $false
                }else{
                    $this.IsRecycleBin = $false
                    $this.IsInRecycleBin = $true
                }
            }else{
                $this.IsRecycleBin = $false
                $this.IsInRecycleBin = $false
            }
        }
        if ([bool]($this.Attributes -band [System.IO.FileAttributes]::ReparsePoint)){
            if ($this.Linktype -eq 'SymbolicLink'){
                $this.IsSymbolicLink = $true
                $this.IsJunction = $false
                $this.IsHardLink = $false
            }
            elseif ($this.Linktype -eq 'Junction'){
                $this.IsSymbolicLink = $false
                $this.IsJunction = $true
                $this.IsHardLink = $false
            }
            else{
                $this.IsSymbolicLink = $false
                $this.IsJunction = $false
                $this.IsHardLink = $false
            }
        }elseif($this.Linktype -eq 'HardLink'){
            $this.IsSymbolicLink = $false
            $this.IsJunction = $false
            $this.IsHardLink = $true
        }else{
            $this.IsSymbolicLink = $false
            $this.IsJunction = $false
            $this.IsHardLink = $false
        }

    }
    [string] PreProcess([string] $Path){
        return [FormattedFileSystemPath]::FormatLiteralPath($this.OriginalPlatform,$Path,$this.Slash)
    }
    static [string] FormatLiteralPath([string]$PathPlatform,[string] $Path, [string] $Slash){
        # Format $Path on Literal level, without any check or validation through file system.
        # See .DESCRIPTION-1 of this class for the details of the formatting rules.
        # It can be used as pre-procession of a path before it is passed to $this.FormatPath().
        ## Check
        if ($Path -match '[\*\?\[\]]'){
            throw "Only literal path is supported, not $($Path) with wildcard characters `*`, `?` or `[]`."
        }
        if ($Path -match '(:+)([^:]+)(:+)'){
            throw "The $($Path) should not contain more than 1 group of consecutive colons."
        }
        ## Normalize at a preliminary level
        $Path = $Path -replace '[:]+', ':'
        $Path = $Path -replace '([^\\/])([\\/])+$', { $_.Groups[1].Value} # Trim the end '\/' but remain the former characters.
        if ($Path -match ":$") {
            $Path = $Path + $Slash
        }
        $Path = $Path -replace '[\\/]', $Slash
        
    
        $PathType = $null
        if ($PathPlatform -eq 'Win32NT'){
            if ($Path.Contains(':')){
                if ($Path -match '^[A-Za-z]:'){
                    $PathType = 'Absolute'
                }
                else{
                    throw "The $($Path) is not supported as the class FormattedFileSystemPath defined."
                }
            }else{
                if ($Path -match '^\\{2,}[^\\]'){
                    $PathType = 'UNC'
                }elseif ($Path -match '^[^\\/:*?"<>|]+'){
                    $PathType = 'Relative'
                }
                else{
                    throw "The $($Path) is not supported as the class FormattedFileSystemPath defined."
                }
            }
        }elseif(!$Path.Contains(':')){  
            if ($Path -match '^/'){
                $PathType = 'Absolute'
            }elseif ($Path -match '^/{2,}[^/]'){
                $PathType = 'UNC'
            }elseif ($Path -match '^[^/\0]+'){
                $PathType = 'Relative'
            }
            else{
                throw "The $($Path) is not supported as the class FormattedFileSystemPath defined."
            }
        }
        # Normalize at a deeper level
        $Path = $Path -replace '[\\/]+', $Slash
        if ($PathType -eq 'Absolute'){
            $Path = $Path.Substring(0,1).ToUpper() + $Path.Substring(1)
        }elseif ($PathType -eq 'UNC'){
            $Path = $Slash + $Path
        }elseif ($PathType -eq 'Relative'){
            $Path = '.' + $Slash + $Path
        }else{
            throw "The $($Path) is not supported as the class FormattedFileSystemPath defined."
        }

        return $Path
    }
    [string] FormatPath([string] $Path){

        try {
            $parent = Split-Path $Path -Parent
        }
        catch {
            $parent = ''
        }
        try {
            $leaf = Split-Path $Path -Leaf
        }
        catch {
            $leaf = ''
        }

        if ($parent -and $leaf){
            $item = (Get-ChildItem $parent -Force| Where-Object Name -eq $leaf)
        }else{
            $item = $null
        }

        if ($item){
            return $item.FullName
        }else{
            return $Path
        }
    }
    [System.Management.Automation.PSDriveInfo] GetQualifier([string]$LiteralPath){
        return (Get-ItemProperty -LiteralPath $LiteralPath).PSDrive
    }
    # [string] GetQualifierWithFirstDir(){

    # $splited_paths = $this.LiteralPath -split '\\'
    # if ($splited_paths.Count -gt 1) { $max_index = 1 } else { $max_index = 0 }
    # return $this.FormatPath($splited_paths[0..$max_index] -join '\\')
    # }
    [string] ToString() { # like __repr__ in python
        return $this.LiteralPath
    }
    [string] ToShortName() {

        return ($this.LiteralPath -replace '[/\\:]+', '-').Trim('-')
    }
}

function Get-FormattedFileSystemPath{
<#
.DESCRIPTION
    A function to apply the class FormattedFileSystemPath on a path.
    Return an instance of it
.PARAMETER Path
    The path to be formatted.
.INPUTS
    String.
.OUTPUTS
    FormattedFileSystemPath.
#>
    param(
        [Parameter(Mandatory)]
        [string]$Path
    )
    return [FormattedFileSystemPath]::new($Path)
}