# Repair-AppShortcuts.ps1
#
# Repoint every shortcut for one app after its install location moves.
#
# WHY THIS EXISTS
#
#   An MSI major upgrade fixes only the shortcuts the MSI itself owns. The
#   copies we place - the Shopfloor Tools folder, and above all the per-user
#   taskbar pin - keep pointing at the old install and the pin dies. Shopfloor
#   bays are locked down so an operator cannot right-click and unpin it, and
#   07-TaskbarLayout cannot help: LayoutModification.xml is read only on the
#   FIRST logon of a NEW profile. Existing profiles never re-read it.
#
# THE TRAP THIS SCRIPT EXISTS TO AVOID (verified in the win11 VM, 2026-09-04)
#
#   The Defect Tracker shortcuts are MSI ADVERTISED (Darwin) shortcuts. Their
#   Shortcut table Target is a Feature name, not a path, so Windows resolves
#   them through the installer at click time. Three consequences:
#
#     1. WScript.Shell reports their TargetPath as
#        C:\Windows\Installer\{ProductCode}\<stub>.exe, not the real exe.
#     2. Setting .TargetPath and calling .Save() REPORTS SUCCESS AND CHANGES
#        NOTHING. WorkingDirectory and IconLocation do change, so the write
#        looks like it worked. This is why the shortcut cannot be repaired
#        in place, and why every write here is read back and verified.
#     3. A major upgrade issues a NEW ProductCode. An advertised shortcut
#        copied out to a pin still names the OLD ProductCode, which no longer
#        exists, so the pin cannot resolve at all. That, not the folder move
#        on its own, is what kills a pinned copy.
#
#   The fix for an advertised copy is to DELETE it and write a fresh plain
#   shortcut to the real exe. Verified to work and to launch.
#
# WHAT IT LEAVES ALONE, ON PURPOSE
#
#   The two locations the MSI owns (All Users Start Menu, Public Desktop) keep
#   their advertised shortcuts when they are still advertised. Those resolve
#   through MSI and self-repair, and converting them to plain shortcuts would
#   throw that away and make the next move need this script again. The MSI
#   upgrade is what fixes those. We only rewrite a copy the MSI does not
#   manage, or an MSI-owned shortcut that has already been flattened to a
#   plain stale path. -Force overrides.
#
#   It does not restart Explorer. A replaced pin resolves on the user's next
#   logon and shopfloor bays log off nightly. Killing Explorer mid-shift to
#   save one logon is not a trade worth making.
#
# Usage (Type=PS1 manifest entry, DetectionMethod=Always):
#   powershell -ExecutionPolicy Bypass -File Repair-AppShortcuts.ps1
#       -ShortcutName Defect_Tracker
#       -ExePath 'C:\Program Files (x86)\WJF_Defect_Tracker\Defect_Tracker.exe'
#       -StalePathPattern 'WJF_Defect_Tracker'

param(
    [Parameter(Mandatory=$true)][string]$ShortcutName,
    [Parameter(Mandatory=$true)][string]$ExePath,
    # Any shortcut whose stored target matches this is claimed even if its
    # filename does not match ShortcutName. Catches a pin someone renamed.
    [string]$StalePathPattern,
    # Rewrite MSI-owned advertised shortcuts too, losing MSI self-repair.
    [switch]$Force,
    [switch]$WhatIfOnly
)

$ErrorActionPreference = 'Continue'

$logDir = 'C:\Logs\Shopfloor'
New-Item -ItemType Directory -Path $logDir -Force -EA SilentlyContinue | Out-Null
$log = Join-Path $logDir ('repair-shortcuts-{0}.log' -f (Get-Date -Format 'yyyyMMdd'))
function Log($m){ "$([DateTime]::Now.ToString('s')) $m" | Tee-Object -FilePath $log -Append | Out-Null }

Log "=== Repair shortcuts: $ShortcutName -> $ExePath ==="

# Nothing to point at means the app is not on this bay, or the manifest ran us
# before the MSI. Rewriting to a path that does not exist turns a stale
# shortcut into a broken one, so leave it and let the next cycle retry.
if (-not (Test-Path -LiteralPath $ExePath -PathType Leaf)) {
    Log "SKIP: target does not exist: $ExePath"
    exit 0
}

$workDir = Split-Path -Parent $ExePath
$leaf    = "$ShortcutName.lnk"

# An advertised shortcut always reports its target inside the installer cache.
$AdvertisedTarget = '^[A-Za-z]:\\Windows\\Installer\\\{'

# Locations the MSI creates and maintains itself.
$msiOwnedDirs = @(
    'C:\ProgramData\Microsoft\Windows\Start Menu\Programs'
    'C:\Users\Public\Desktop'
)
# Copies we place. The MSI does not know about these and will never fix them.
$ourDirs = @(
    'C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Shopfloor Tools'
    'C:\Users\Public\Desktop\Shopfloor Tools'
)
foreach ($profileDir in (Get-ChildItem 'C:\Users' -Directory -EA SilentlyContinue)) {
    $quick = Join-Path $profileDir.FullName 'AppData\Roaming\Microsoft\Internet Explorer\Quick Launch\User Pinned'
    $ourDirs += (Join-Path $quick 'TaskBar')
    $ourDirs += (Join-Path $quick 'StartMenu')
}

$wsh = New-Object -ComObject WScript.Shell
$checked = 0; $fixed = 0; $failed = 0; $skipped = 0

function Get-Target([string]$Path) {
    try { return $wsh.CreateShortcut($Path).TargetPath } catch { return $null }
}

function Repair-Lnk([string]$Path, [bool]$MsiOwned) {
    $script:checked++
    $current = Get-Target $Path
    if ($null -eq $current) {
        Log "  READ FAIL $Path"
        $script:failed++
        return
    }

    $advertised = $current -match $AdvertisedTarget

    if ($current -eq $ExePath) { Log "  ok $Path"; return }

    # An MSI-owned shortcut that is still advertised resolves through the
    # installer and the upgrade will correct it. Flattening it would cost us
    # self-repair for no gain.
    if ($advertised -and $MsiOwned -and -not $Force) {
        Log "  skip (MSI-owned, still advertised, upgrade will fix) $Path"
        $script:skipped++
        return
    }

    if ($WhatIfOnly) {
        Log "  WOULD FIX $Path : '$current' becomes '$ExePath'"
        $script:fixed++
        return
    }

    # Delete first. An advertised shortcut cannot be repointed in place: the
    # Save() succeeds and the target stays exactly as it was.
    try {
        Remove-Item -LiteralPath $Path -Force -ErrorAction Stop
        $sc = $wsh.CreateShortcut($Path)
        $sc.TargetPath       = $ExePath
        $sc.WorkingDirectory = $workDir
        $sc.IconLocation     = "$ExePath,0"
        $sc.Save()
    } catch {
        Log "  WRITE FAIL $Path : $($_.Exception.Message)"
        $script:failed++
        return
    }

    # Read back. This is the whole point: a write that silently did nothing
    # must be reported as a failure, not counted as a fix.
    $after = Get-Target $Path
    if ($after -eq $ExePath) {
        Log "  FIXED $Path : '$current' becomes '$ExePath'"
        $script:fixed++
    } else {
        Log "  VERIFY FAIL $Path : wrote '$ExePath', reads back '$after'"
        $script:failed++
    }
}

function Test-Claimed([System.IO.FileInfo]$File) {
    if ($File.Name -ieq $leaf) { return $true }
    if (-not $StalePathPattern) { return $false }
    $t = Get-Target $File.FullName
    return ($t -and $t -match [regex]::Escape($StalePathPattern))
}

foreach ($pair in @(@{ Dirs = $msiOwnedDirs; Msi = $true }, @{ Dirs = $ourDirs; Msi = $false })) {
    foreach ($dir in $pair.Dirs) {
        if (-not (Test-Path -LiteralPath $dir -PathType Container)) { continue }
        foreach ($f in (Get-ChildItem -LiteralPath $dir -Filter '*.lnk' -File -EA SilentlyContinue)) {
            if (Test-Claimed $f) { Repair-Lnk $f.FullName $pair.Msi }
        }
    }
}

try { [System.Runtime.InteropServices.Marshal]::ReleaseComObject($wsh) | Out-Null } catch {}

Log "=== done: $checked checked, $fixed fixed, $skipped skipped, $failed failed ==="
if ($failed -gt 0) { exit 1 }
exit 0