#Requires -Version 5.1
param(
    [Parameter(Mandatory=$true)]
    [string]$Path
)

$ErrorActionPreference = "Stop"
Add-Type -AssemblyName System.Windows.Forms
Add-Type -AssemblyName System.Drawing

function Get-Config {
    $configPaths = @(
        "$env:APPDATA\FreigabeKontextmenue\config.json",
        "$env:ProgramData\FreigabeKontextmenue\config.json"
    )
    
    foreach ($configPath in $configPaths) {
        if (Test-Path $configPath) {
            return Get-Content $configPath -Raw | ConvertFrom-Json
        }
    }
    
    throw "Konfiguration nicht gefunden. Bitte zuerst installieren!"
}

function Get-UNCPath {
    param([string]$LocalPath)
    
    $drive = Split-Path -Path $LocalPath -Qualifier
    $driveLetter = $drive.TrimEnd(':')
    
    $netUse = net use 2>$null | Where-Object { $_ -match "^\s*\w*\s+$driveLetter`:" }
    
    if ($netUse) {
        $parts = $netUse -split '\s+'
        foreach ($part in $parts) {
            if ($part -match '^\\\\') {
                $uncRoot = $part
                $relativePath = $LocalPath.Substring($drive.Length)
                return Join-Path $uncRoot $relativePath
            }
        }
    }
    
    $psDrive = Get-PSDrive -Name $driveLetter -ErrorAction SilentlyContinue
    if ($psDrive -and $psDrive.DisplayRoot) {
        $relativePath = $LocalPath.Substring($drive.Length)
        return Join-Path $psDrive.DisplayRoot $relativePath
    }
    
    $wmiDrive = Get-WmiObject -Class Win32_LogicalDisk -Filter "DeviceID='$drive'" -ErrorAction SilentlyContinue
    if ($wmiDrive -and $wmiDrive.ProviderName) {
        $relativePath = $LocalPath.Substring($drive.Length)
        return Join-Path $wmiDrive.ProviderName $relativePath
    }
    
    $computerName = $env:COMPUTERNAME
    $adminShare = "\\$computerName\$driveLetter`$"
    $relativePath = $LocalPath.Substring($drive.Length)
    return Join-Path $adminShare $relativePath
}

function Get-DomainUsers {
    $users = @()

    try {
        $searcher = [adsisearcher]"(&(objectCategory=person)(objectClass=user))"
        $searcher.PageSize = 1000
        $searcher.PropertiesToLoad.AddRange(@("samaccountname", "displayname", "mail"))

        # NetBIOS-Domänennamen ermitteln
        $rootDSE = [ADSI]"LDAP://RootDSE"
        $domainDN = $rootDSE.defaultNamingContext
        $domainSearcher = [adsisearcher]"(&(objectClass=domain))"
        $domainSearcher.SearchRoot = [ADSI]"LDAP://$domainDN"
        $domainResult = $domainSearcher.FindOne()
        $netbiosDomain = $null

        # NetBIOS-Name aus Partitions holen
        $configDN = $rootDSE.configurationNamingContext
        $partSearcher = [adsisearcher]"(&(objectClass=crossRef)(nCName=$domainDN))"
        $partSearcher.SearchRoot = [ADSI]"LDAP://CN=Partitions,$configDN"
        $partResult = $partSearcher.FindOne()
        if ($partResult -and $partResult.Properties["netbiosname"]) {
            $netbiosDomain = $partResult.Properties["netbiosname"][0]
        }

        # Fallback: Aus USERDOMAIN
        if (-not $netbiosDomain) {
            $netbiosDomain = $env:USERDOMAIN
        }

        $results = $searcher.FindAll()
        foreach ($result in $results) {
            $samAccount = $result.Properties["samaccountname"][0]
            $displayName = if ($result.Properties["displayname"]) { $result.Properties["displayname"][0] } else { $samAccount }
            $qualifiedName = "$netbiosDomain\$samAccount"

            $users += [PSCustomObject]@{
                SamAccountName = $samAccount
                DisplayName = $displayName
                FullName = "$displayName ($samAccount)"
                QualifiedName = $qualifiedName
                Domain = $netbiosDomain
                IsLocal = $false
            }
        }
    } catch {
        # Fallback auf lokale Benutzer (kein AD verfügbar)
        $localUsers = Get-LocalUser -ErrorAction SilentlyContinue | Where-Object { $_.Enabled }
        foreach ($user in $localUsers) {
            $users += [PSCustomObject]@{
                SamAccountName = $user.Name
                DisplayName = if ($user.FullName) { $user.FullName } else { $user.Name }
                FullName = if ($user.FullName) { "$($user.FullName) ($($user.Name))" } else { $user.Name }
                QualifiedName = "$env:COMPUTERNAME\$($user.Name)"
                Domain = $env:COMPUTERNAME
                IsLocal = $true
            }
        }
    }

    return $users | Sort-Object DisplayName
}

function Show-UserSelectionDialog {
    param([array]$Users)

    $form = New-Object System.Windows.Forms.Form
    $form.Text = "Benutzer ausw$([char]0x00E4)hlen - Freigabe"
    $form.Size = New-Object System.Drawing.Size(450, 530)
    $form.StartPosition = "CenterScreen"
    $form.FormBorderStyle = "FixedDialog"
    $form.MaximizeBox = $false

    $lblSearch = New-Object System.Windows.Forms.Label
    $lblSearch.Text = "Suchen:"
    $lblSearch.Location = New-Object System.Drawing.Point(10, 15)
    $lblSearch.Size = New-Object System.Drawing.Size(50, 20)
    $form.Controls.Add($lblSearch)

    $txtSearch = New-Object System.Windows.Forms.TextBox
    $txtSearch.Location = New-Object System.Drawing.Point(65, 12)
    $txtSearch.Size = New-Object System.Drawing.Size(355, 20)
    $form.Controls.Add($txtSearch)

    $listBox = New-Object System.Windows.Forms.ListBox
    $listBox.Location = New-Object System.Drawing.Point(10, 45)
    $listBox.Size = New-Object System.Drawing.Size(410, 330)
    $listBox.Font = New-Object System.Drawing.Font("Segoe UI", 10)
    $form.Controls.Add($listBox)

    $script:allUsers = $Users
    foreach ($user in $Users) {
        $listBox.Items.Add($user.FullName) | Out-Null
    }

    $txtSearch.Add_TextChanged({
        $searchText = $txtSearch.Text.ToLower()
        $listBox.Items.Clear()
        foreach ($user in $script:allUsers) {
            if ($user.FullName.ToLower().Contains($searchText) -or
                $user.SamAccountName.ToLower().Contains($searchText)) {
                $listBox.Items.Add($user.FullName) | Out-Null
            }
        }
    })

    $chkFullPath = New-Object System.Windows.Forms.CheckBox
    $chkFullPath.Text = "Kompletten Pfad in Verkn$([char]0x00FC)pfungsname schreiben"
    $chkFullPath.Location = New-Object System.Drawing.Point(10, 385)
    $chkFullPath.Size = New-Object System.Drawing.Size(410, 25)
    $chkFullPath.Font = New-Object System.Drawing.Font("Segoe UI", 9)
    $form.Controls.Add($chkFullPath)

    $lblExample = New-Object System.Windows.Forms.Label
    $lblExample.Text = "(z.B. 'Mandanten - S - Schmidt - Lohn' statt nur 'Lohn')"
    $lblExample.Location = New-Object System.Drawing.Point(27, 408)
    $lblExample.Size = New-Object System.Drawing.Size(400, 20)
    $lblExample.ForeColor = [System.Drawing.Color]::Gray
    $lblExample.Font = New-Object System.Drawing.Font("Segoe UI", 8)
    $form.Controls.Add($lblExample)

    $okBtn = New-Object System.Windows.Forms.Button
    $okBtn.Text = "Freigeben"
    $okBtn.Location = New-Object System.Drawing.Point(240, 450)
    $okBtn.Size = New-Object System.Drawing.Size(85, 30)
    $okBtn.Enabled = $false
    $okBtn.DialogResult = [System.Windows.Forms.DialogResult]::OK
    $form.AcceptButton = $okBtn
    $form.Controls.Add($okBtn)

    $cancelBtn = New-Object System.Windows.Forms.Button
    $cancelBtn.Text = "Abbrechen"
    $cancelBtn.Location = New-Object System.Drawing.Point(335, 450)
    $cancelBtn.Size = New-Object System.Drawing.Size(85, 30)
    $cancelBtn.DialogResult = [System.Windows.Forms.DialogResult]::Cancel
    $form.CancelButton = $cancelBtn
    $form.Controls.Add($cancelBtn)

    $listBox.Add_SelectedIndexChanged({
        $okBtn.Enabled = $listBox.SelectedIndex -ge 0
    })

    $listBox.Add_DoubleClick({
        if ($listBox.SelectedIndex -ge 0) {
            $form.DialogResult = [System.Windows.Forms.DialogResult]::OK
            $form.Close()
        }
    })

    $script:selectedUser = $null
    $script:useFullPath = $false

    if ($form.ShowDialog() -eq [System.Windows.Forms.DialogResult]::OK -and $listBox.SelectedIndex -ge 0) {
        $selectedText = $listBox.SelectedItem
        $script:selectedUser = $script:allUsers | Where-Object { $_.FullName -eq $selectedText } | Select-Object -First 1
        $script:useFullPath = $chkFullPath.Checked
    }

    return @{
        User = $script:selectedUser
        UseFullPath = $script:useFullPath
    }
}

function Add-FreigabePermission {
    param(
        [string]$TargetPath,
        [string]$QualifiedUserName
    )

    try {
        $acl = Get-Acl -Path $TargetPath

        $rights = [System.Security.AccessControl.FileSystemRights]::FullControl
        $inheritance = [System.Security.AccessControl.InheritanceFlags]::ContainerInherit -bor [System.Security.AccessControl.InheritanceFlags]::ObjectInherit
        $propagation = [System.Security.AccessControl.PropagationFlags]::None
        $type = [System.Security.AccessControl.AccessControlType]::Allow

        $rule = New-Object System.Security.AccessControl.FileSystemAccessRule($QualifiedUserName, $rights, $inheritance, $propagation, $type)
        $acl.AddAccessRule($rule)
        Set-Acl -Path $TargetPath -AclObject $acl

        return $true
    } catch {
        throw "Fehler beim Setzen der Berechtigungen: $_"
    }
}

function Create-Shortcut {
    param(
        [string]$TargetPath,
        [string]$ShortcutPath
    )
    
    $shell = New-Object -ComObject WScript.Shell
    $shortcut = $shell.CreateShortcut($ShortcutPath)
    $shortcut.TargetPath = $TargetPath
    $shortcut.Save()
    [System.Runtime.Interopservices.Marshal]::ReleaseComObject($shell) | Out-Null
}

function Save-FreigabeInfo {
    param(
        [string]$TargetPath,
        [string]$UserName
    )
    
    $metaDir = if (Test-Path "$env:ProgramData\FreigabeKontextmenue") {
        "$env:ProgramData\FreigabeKontextmenue\meta"
    } else {
        "$env:APPDATA\FreigabeKontextmenue\meta"
    }
    
    if (-not (Test-Path $metaDir)) {
        New-Item -Path $metaDir -ItemType Directory -Force | Out-Null
    }
    
    $pathHash = [System.BitConverter]::ToString([System.Security.Cryptography.MD5]::Create().ComputeHash([System.Text.Encoding]::UTF8.GetBytes($TargetPath))).Replace("-","")
    $metaFile = Join-Path $metaDir "$pathHash.json"
    
    $meta = @{
        TargetPath = $TargetPath
        Users = @()
    }
    
    if (Test-Path $metaFile) {
        $existing = Get-Content $metaFile -Raw | ConvertFrom-Json
        $meta.Users = @($existing.Users)
    }
    
    if ($UserName -notin $meta.Users) {
        $meta.Users += $UserName
    }
    
    $meta | ConvertTo-Json | Set-Content -Path $metaFile -Encoding UTF8
}

try {
    $config = Get-Config
    $basePath = $config.LinkBasePath
    
    if (-not (Test-Path $Path)) {
        throw "Der Pfad existiert nicht: $Path"
    }
    
    $users = Get-DomainUsers
    if ($users.Count -eq 0) {
        throw "Keine Benutzer gefunden!"
    }
    
    $dialogResult = Show-UserSelectionDialog -Users $users
    if (-not $dialogResult.User) {
        exit 0
    }

    $selectedUser = $dialogResult.User
    $useFullPath = $dialogResult.UseFullPath

    $userName = $selectedUser.SamAccountName
    $userFolder = Join-Path $basePath $userName

    if (-not (Test-Path $userFolder)) {
        New-Item -Path $userFolder -ItemType Directory -Force | Out-Null
    }

    $uncPath = Get-UNCPath -LocalPath $Path

    # Verknuepfungsname erstellen
    if ($useFullPath) {
        # Kompletten Pfad verwenden: \\server\Mandanten\S\Schmidt\Lohn -> Mandanten - S - Schmidt - Lohn
        $pathForName = $uncPath
        # UNC-Prefix und Servernamen entfernen
        if ($pathForName -match '^\\\\[^\\]+\\(.+)$') {
            $pathForName = $Matches[1]
        }
        # Backslashes durch " - " ersetzen
        $itemName = $pathForName -replace '\\', ' - '
    } else {
        $itemName = Split-Path -Path $Path -Leaf
    }

    # Ungueltige Zeichen fuer Dateinamen entfernen/ersetzen
    # Verboten in Windows-Dateinamen: \ / : * ? " < > |
    $itemName = $itemName -replace '[\\/:*?"<>|]', '_'

    $shortcutPath = Join-Path $userFolder "$itemName.lnk"

    $counter = 1
    while (Test-Path $shortcutPath) {
        $baseName = $itemName
        $shortcutPath = Join-Path $userFolder "$baseName ($counter).lnk"
        $counter++
    }

    Create-Shortcut -TargetPath $uncPath -ShortcutPath $shortcutPath
    Add-FreigabePermission -TargetPath $Path -QualifiedUserName $selectedUser.QualifiedName
    Save-FreigabeInfo -TargetPath $Path -UserName $selectedUser.QualifiedName

    [System.Windows.Forms.MessageBox]::Show(
        "Freigabe erfolgreich erstellt!`n`nBenutzer: $($selectedUser.DisplayName)`nVerkn$([char]0x00FC)pfung: $shortcutPath`nUNC-Pfad: $uncPath",
        "Freigabe erfolgreich",
        [System.Windows.Forms.MessageBoxButtons]::OK,
        [System.Windows.Forms.MessageBoxIcon]::Information
    )
    
} catch {
    [System.Windows.Forms.MessageBox]::Show(
        "Fehler: $($_.Exception.Message)",
        "Fehler bei Freigabe",
        [System.Windows.Forms.MessageBoxButtons]::OK,
        [System.Windows.Forms.MessageBoxIcon]::Error
    )
    exit 1
}