context tunnel - powershell

tunnel.ps1

<#
.SYNOPSIS
    Tunnel Manager for AI Context (Windows Version)
.DESCRIPTION
    Creates or removes symbolic links to external folders to allow AI Agents
    to access them as local context.
.EXAMPLE
    .\tunnel.ps1 link "C:\Projects\ReferenceRepo" "_TEMPLATE"
    .\tunnel.ps1 unlink "_TEMPLATE"
#>

param (
    [Parameter(Mandatory=$true, Position=0)]
    [ValidateSet("link", "unlink")]
    [string]$Command,

    [Parameter(Position=1)]
    [string]$SourcePath,

    [Parameter(Position=2)]
    [string]$TargetName = "TEMPLATE"
)

# --- Helper for Colors ---
function Log-Info ($msg) { Write-Host "✔ $msg" -ForegroundColor Green }
function Log-Warn ($msg) { Write-Host "⚠ $msg" -ForegroundColor Yellow }
function Log-Error ($msg) { Write-Host "✖ $msg" -ForegroundColor Red }

# --- LINK COMMAND ---
if ($Command -eq "link") {
    if ([string]::IsNullOrWhiteSpace($SourcePath)) {
        Log-Error "Missing source path. Usage: .\tunnel.ps1 link <path> [name]"
        exit 1
    }

    # 1. Validate Source
    if (-not (Test-Path -Path $SourcePath)) {
        Log-Error "Source directory does not exist: $SourcePath"
        exit 1
    }

    # Get Absolute Path to ensure the link works reliably
    $AbsSourcePath = (Resolve-Path $SourcePath).Path

    # Check for circular links
    $SourceItem = Get-Item -Path $AbsSourcePath -ErrorAction SilentlyContinue
    if ($SourceItem.LinkType -eq "SymbolicLink" -or $SourceItem.Attributes -match "ReparsePoint") {
        try {
            $ResolvedPath = $SourceItem.Target
            $CurrentDir = (Get-Location).Path
            if ($ResolvedPath -match [regex]::Escape($CurrentDir) -or $ResolvedPath -match [regex]::Escape($TargetName)) {
                Log-Error "Creating this link would form a circular dependency."
                exit 1
            }
        }
        catch {
            Log-Error "Could not resolve link target."
            exit 1
        }
    }

    # 2. Check if Target already exists
    if (Test-Path -Path $TargetName) {
        Log-Error "A file or folder named '$TargetName' already exists here."
        exit 1
    }

    # 3. Create Symlink
    try {
        New-Item -ItemType SymbolicLink -Path ".\$TargetName" -Target $AbsSourcePath | Out-Null
        Log-Info "Linked '$TargetName' -> '$AbsSourcePath'"
    }
    catch {
        Log-Error "Failed to create symlink. Ensure you are running as Administrator or have Developer Mode enabled."
        Write-Host $_
        exit 1
    }

    # 4. Handle .gitignore
    $GitIgnoreFile = ".gitignore"
    if (-not (Test-Path $GitIgnoreFile)) {
        New-Item $GitIgnoreFile -ItemType File | Out-Null
        Log-Warn "Created .gitignore file."
    }

    # Check if entry exists
    $Content = Get-Content $GitIgnoreFile -ErrorAction SilentlyContinue
    if ($Content -contains $TargetName) {
        Log-Info "'$TargetName' is already in .gitignore"
    }
    else {
        Add-Content -Path $GitIgnoreFile -Value "$TargetName"
        Log-Info "Added '$TargetName' to .gitignore"
    }
}

# --- UNLINK COMMAND ---
elseif ($Command -eq "unlink") {
    # If user ran "unlink", SourcePath might be empty, so we check if they passed a name in pos 1 or 2
    # Logic: if user typed "unlink MyLink", $SourcePath holds "MyLink" because of position.
    if (-not [string]::IsNullOrWhiteSpace($SourcePath)) {
        $TargetName = $SourcePath
    }

    # 1. Validate it exists
    if (-not (Test-Path -Path $TargetName)) {
        Log-Error "'$TargetName' not found."
        exit 1
    }

    # 2. Validate it is a Symlink/ReparsePoint (Safety Check)
    $Item = Get-Item -Path $TargetName
    if ($Item.LinkType -ne "SymbolicLink" -and $Item.Attributes -notmatch "ReparsePoint") {
        Log-Error "CRITICAL: '$TargetName' is a real directory, not a link!"
        Log-Error "Aborting to prevent data loss."
        exit 1
    }

    # 3. Remove the link
    try {
        Remove-Item -Path $TargetName -Force
        Log-Info "Unlinked '$TargetName'"
    }
    catch {
        Log-Error "Failed to remove link."
        Write-Host $_
        exit 1
    }
}