Refactor Windows installer for side-by-side updates and improved directory handling

- Updated the NSIS installer to support side-by-side updates, allowing the running application to remain active while a new version is staged in a separate directory.
- Modified the installation directory handling to ensure the correct paths are used for shortcuts and registry entries.
- Enhanced the update process to include a retry mechanism for folder swaps, improving reliability during updates.
- Adjusted comments and documentation for clarity on the update process and its implications.

packaging/windows/farmcontrol.nsi

@@ -60,12 +60,14 @@ Function .onInit
   !insertmacro progressStatus "Starting Farm Control installation..."
   !insertmacro progressPercent 5
 
-  ; In-app updates keep the running process alive for progress UI.
+  ; In-app updates install into Farm Control.new while the running process
+  ; keeps using Farm Control; the folders are swapped after exit (/RESTARTFC).
   ; Interactive / silent fresh installs still remove the previous version first.
   ${If} $IsInAppUpdate == "1"
-    !insertmacro prepareInPlaceUpdate
+    !insertmacro prepareSideBySideUpdate
     !insertmacro progressPercent 15
   ${Else}
+    StrCpy $FinalInstDir $INSTDIR
     !insertmacro uninstallPreviousFarmControl
     !insertmacro progressPercent 20
   ${EndIf}
@@ -97,7 +99,7 @@ Section "Farm Control" SecMain
   !insertmacro progressStatus "Writing uninstall information..."
   !insertmacro progressPercent 90
 
-  WriteRegStr HKCU "Software\Tom Butcher\Farm Control" "InstallDir" $INSTDIR
+  WriteRegStr HKCU "Software\Tom Butcher\Farm Control" "InstallDir" $FinalInstDir
   WriteRegStr HKCU "Software\Microsoft\Windows\CurrentVersion\Uninstall\Farm Control" \
     "DisplayName" "Farm Control"
   WriteRegStr HKCU "Software\Microsoft\Windows\CurrentVersion\Uninstall\Farm Control" \
@@ -105,7 +107,7 @@ Section "Farm Control" SecMain
   WriteRegStr HKCU "Software\Microsoft\Windows\CurrentVersion\Uninstall\Farm Control" \
     "Publisher" "Tom Butcher"
   WriteRegStr HKCU "Software\Microsoft\Windows\CurrentVersion\Uninstall\Farm Control" \
-    "UninstallString" "$INSTDIR\Uninstall.exe"
+    "UninstallString" "$FinalInstDir\Uninstall.exe"
   WriteRegDWORD HKCU "Software\Microsoft\Windows\CurrentVersion\Uninstall\Farm Control" \
     "NoModify" 1
   WriteRegDWORD HKCU "Software\Microsoft\Windows\CurrentVersion\Uninstall\Farm Control" \

packaging/windows/installer.nsh

@@ -5,11 +5,13 @@
 Var ProgressLogFile
 Var IsInAppUpdate
 Var RestartAfterInstall
+Var FinalInstDir
 
 !macro initProgressLog
   StrCpy $ProgressLogFile ""
   StrCpy $IsInAppUpdate "0"
   StrCpy $RestartAfterInstall "0"
+  StrCpy $FinalInstDir ""
 
   ${GetParameters} $R9
 
@@ -104,36 +106,48 @@ Var RestartAfterInstall
   ExecWait 'taskkill /F /IM launcher.exe /T' $R0
 !macroend
 
-; Windows allows renaming open executables; move locked binaries aside so File can replace them.
+; Side-by-side update: install into Farm Control.new while the running app
-!macro moveAsideIfPresent filePath
+; keeps using Farm Control, then swap folders after the process exits.
-  ${If} ${FileExists} "${filePath}"
+!macro prepareSideBySideUpdate
-    Delete "${filePath}.old"
+  !insertmacro progressPhase "Preparing update"
-    ClearErrors
+  !insertmacro progressStatus "Preparing staging folder for update..."
-    Rename "${filePath}" "${filePath}.old"
+
-    ClearErrors
+  StrCpy $FinalInstDir $INSTDIR
+  StrCpy $INSTDIR "$FinalInstDir.new"
+
+  ${If} ${FileExists} "$INSTDIR"
+    DetailPrint "Removing leftover staging folder..."
+    RMDir /r "$INSTDIR"
   ${EndIf}
 !macroend
 
-; Prefer renaming the whole bin dir (works even with open files inside).
+!macro swapUpdateStaging
-!macro prepareInPlaceUpdate
+  !insertmacro progressPhase "Applying update"
-  !insertmacro progressPhase "Preparing update"
+  !insertmacro progressStatus "Replacing Farm Control with the new version..."
-  !insertmacro progressStatus "Preparing files for update..."
+  DetailPrint "Replacing Farm Control with staged update..."
 
-  ${If} ${FileExists} "$INSTDIR\bin.old"
+  StrCpy $R7 0
-    RMDir /r "$INSTDIR\bin.old"
+  swap_delete_retry:
+    RMDir /r "$FinalInstDir"
+    ${If} ${FileExists} "$FinalInstDir"
+      IntOp $R7 $R7 + 1
+      ${If} $R7 < 20
+        Sleep 500
+        Goto swap_delete_retry
+      ${EndIf}
+      !insertmacro progressFailure "Could not remove the previous Farm Control installation."
+      Abort
     ${EndIf}
 
-  ${If} ${FileExists} "$INSTDIR\bin"
   ClearErrors
-    Rename "$INSTDIR\bin" "$INSTDIR\bin.old"
+  Rename "$INSTDIR" "$FinalInstDir"
   ${If} ${Errors}
-      !insertmacro moveAsideIfPresent "$INSTDIR\bin\FarmControl.exe"
+    !insertmacro progressFailure "Could not activate the new Farm Control installation."
-      !insertmacro moveAsideIfPresent "$INSTDIR\bin\launcher.exe"
+    Abort
-      !insertmacro moveAsideIfPresent "$INSTDIR\bin\bun.exe"
-      !insertmacro moveAsideIfPresent "$INSTDIR\bin\bspatch.exe"
-      !insertmacro moveAsideIfPresent "$INSTDIR\bin\zig-zstd.exe"
-    ${EndIf}
   ${EndIf}
+
+  StrCpy $INSTDIR $FinalInstDir
+  !insertmacro progressLog "installer:STATUS:Update files activated"
 !macroend
 
 !macro uninstallPreviousFarmControl
@@ -180,15 +194,15 @@ Var RestartAfterInstall
 
 !macro createDesktopShortcut
   SetShellVarContext current
-  SetOutPath "$INSTDIR\bin"
+  SetOutPath "$FinalInstDir\bin"
-  CreateShortCut "$DESKTOP\Farm Control.lnk" "$INSTDIR\bin\FarmControl.exe" "" "$INSTDIR\bin\FarmControl.exe" 0 SW_SHOWNORMAL "" "Farm Control"
+  CreateShortCut "$DESKTOP\Farm Control.lnk" "$FinalInstDir\bin\FarmControl.exe" "" "$FinalInstDir\bin\FarmControl.exe" 0 SW_SHOWNORMAL "" "Farm Control"
 !macroend
 
 !macro createStartMenuShortcut
   SetShellVarContext current
   CreateDirectory "$SMPROGRAMS\Farm Control"
-  SetOutPath "$INSTDIR\bin"
+  SetOutPath "$FinalInstDir\bin"
-  CreateShortCut "$SMPROGRAMS\Farm Control\Farm Control.lnk" "$INSTDIR\bin\FarmControl.exe" "" "$INSTDIR\bin\FarmControl.exe" 0 SW_SHOWNORMAL "" "Farm Control"
+  CreateShortCut "$SMPROGRAMS\Farm Control\Farm Control.lnk" "$FinalInstDir\bin\FarmControl.exe" "" "$FinalInstDir\bin\FarmControl.exe" 0 SW_SHOWNORMAL "" "Farm Control"
 !macroend
 
 !macro removeDesktopShortcut
@@ -202,16 +216,6 @@ Var RestartAfterInstall
   RMDir "$SMPROGRAMS\Farm Control"
 !macroend
 
-!macro cleanupUpdateBackups
-  ; Best-effort; may fail while the previous process still holds handles.
-  RMDir /r "$INSTDIR\bin.old"
-  Delete "$INSTDIR\bin\FarmControl.exe.old"
-  Delete "$INSTDIR\bin\launcher.exe.old"
-  Delete "$INSTDIR\bin\bun.exe.old"
-  Delete "$INSTDIR\bin\bspatch.exe.old"
-  Delete "$INSTDIR\bin\zig-zstd.exe.old"
-!macroend
-
 !macro customInstall
   !insertmacro progressPhase "Configuring Farm Control"
   !insertmacro progressStatus "Registering farmcontrol URI handler..."
@@ -219,20 +223,15 @@ Var RestartAfterInstall
   DeleteRegKey HKCU "Software\Classes\farmcontrol"
   WriteRegStr HKCU "Software\Classes\farmcontrol" "" "URL:farmcontrol"
   WriteRegStr HKCU "Software\Classes\farmcontrol" "URL Protocol" ""
-  WriteRegStr HKCU "Software\Classes\farmcontrol\DefaultIcon" "" "$INSTDIR\bin\FarmControl.exe"
+  WriteRegStr HKCU "Software\Classes\farmcontrol\DefaultIcon" "" "$FinalInstDir\bin\FarmControl.exe"
   WriteRegStr HKCU "Software\Classes\farmcontrol\shell" "" ""
   WriteRegStr HKCU "Software\Classes\farmcontrol\shell\Open" "" ""
-  WriteRegStr HKCU "Software\Classes\farmcontrol\shell\Open\command" "" '"$INSTDIR\bin\bun.exe" "$INSTDIR\bin\deeplink.js" "%1"'
+  WriteRegStr HKCU "Software\Classes\farmcontrol\shell\Open\command" "" '"$FinalInstDir\bin\bun.exe" "$FinalInstDir\bin\deeplink.js" "%1"'
 
   !insertmacro progressStatus "Creating shortcuts..."
   DetailPrint "Creating shortcuts"
   !insertmacro createDesktopShortcut
   !insertmacro createStartMenuShortcut
-
-  ; Don't remove bin.old during an in-app update — the running process still uses it.
-  ${If} $IsInAppUpdate != "1"
-    !insertmacro cleanupUpdateBackups
-  ${EndIf}
 !macroend
 
 !macro customUnInstall
@@ -241,7 +240,8 @@ Var RestartAfterInstall
   DeleteRegKey HKCU "Software\Classes\farmcontrol"
 !macroend
 
-; Wait for the running app to exit, then relaunch. Only used when /RESTARTFC is passed.
+; Wait for the running app to exit, swap staged update into place, then relaunch.
+; Only used when /RESTARTFC is passed.
 Function restartFarmControlAfterUpdate
   ${If} $RestartAfterInstall != "1"
     Return
@@ -262,7 +262,11 @@ Function restartFarmControlAfterUpdate
       Goto restart_wait_loop
     ${EndIf}
 
+  ${If} $IsInAppUpdate == "1"
+    !insertmacro swapUpdateStaging
+  ${EndIf}
+
   !insertmacro progressStatus "Starting Farm Control..."
-  SetOutPath "$INSTDIR\bin"
+  SetOutPath "$FinalInstDir\bin"
-  Exec "$INSTDIR\bin\FarmControl.exe"
+  Exec "$FinalInstDir\bin\FarmControl.exe"
 FunctionEnd

src/desktop/updater-runner.js

@@ -81,8 +81,7 @@ export const resolveAppLaunchPath = () => {
   }
 
   if (process.platform === 'win32') {
-    // Prefer the installed launcher so post-update restart targets the new binary
+    // Prefer the installed launcher so restarts target the registered install dir.
-    // (in-app updates may leave the running process under bin.old).
     const installDir = readWindowsInstallDirFromRegistry()
     if (installDir) {
       const launcherFromRegistry = resolveExistingLauncher(

src/desktop/winappupdate.js

@@ -220,8 +220,8 @@ export const launchWindowsInstaller = async (
 
     // Silent NSIS install in a detached child process (not a batch file).
     // /S = silent (https://nsis.sourceforge.io/Reference/SilentInstall)
-    // /UPDATE = in-app update (skip killing this process; overwrite in place)
+    // /UPDATE = in-app update (stage into Farm Control.new; swap after exit)
-    // /RESTARTFC = installer waits for this process to exit and relaunches the app
+    // /RESTARTFC = installer waits for this process to exit, swaps folders, relaunches
     // /LOG= + FARMCONTROL_INSTALL_LOG = progress log (installer:% / PHASE / STATUS)
     const installerArgs = [
       '/S',