---
phase: 04-script-generation
plan: "01"
subsystem: script-generator
tags: [jinja2, powershell, tdd, wow64, uac, pnputil, idempotency]
one_liner: "Jinja2-based install.ps1 generator with WOW64 guard, UAC elevation, pnputil two-step, and duplex mapping"
dependency_graph:
  requires: []
  provides: [render_install, install.ps1.j2]
  affects: [imptune.generators.script_generator, imptune.templates.scripts]
tech_stack:
  added: []
  patterns:
    - Jinja2 FileSystemLoader with trim_blocks + lstrip_blocks for PowerShell templates
    - Plain-string function parameters for DB-free unit testability
    - _duplex_map translation dict (model values -> PowerShell cmdlet values)
key_files:
  created:
    - imptune/generators/script_generator.py
    - imptune/templates/scripts/install.ps1.j2
    - tests/test_script_generator.py
  modified: []
decisions:
  - "render_install() takes plain string args (not ORM Printer object) — keeps tests DB-free"
  - "Boolean color_mode/collate converted to lowercase 'true'/'false' strings; template adds $ prefix"
  - "_duplex_map translates before rendering: LongEdge->TwoSidedLongEdge, ShortEdge->TwoSidedShortEdge"
  - "WOW64 guard comment avoids 'pnputil.exe' text to preserve ordering assertion in test"
metrics:
  duration: "~2 min"
  completed_date: "2026-04-10"
  tasks_completed: 1
  files_created: 3
  files_modified: 0
  tests_added: 7
  tests_passing: 68
requirements-completed: [SCRPT-01, SCRPT-04, SCRPT-05]
---

# Phase 4 Plan 01: Script Generator (Install) Summary

**One-liner:** Jinja2-based install.ps1 generator with WOW64 guard, UAC elevation, pnputil two-step, and duplex mapping

## What Was Built

A TDD-developed module `imptune/generators/script_generator.py` with a single public function `render_install()` that renders the `install.ps1.j2` Jinja2 template into a complete, production-ready PowerShell printer install script.

### render_install() function

- Takes plain string arguments (no ORM dependency) for easy unit testing
- Translates `duplex_mode` via `_duplex_map` before passing to template
- Converts Python booleans to lowercase strings (`"true"`/`"false"`) for PowerShell `$true`/`$false` rendering

### install.ps1.j2 template structure (in order)

1. Header comment with printer name and required Intune install command
2. WOW64 guard (`$env:PROCESSOR_ARCHITECTURE` + `SysNative` relaunch) — FIRST executable block
3. SYSTEM vs admin detection (`[WindowsIdentity]::GetCurrent()`, `IsSystem`, `IsInRole(Administrator)`) + UAC self-elevation via `Start-Process -Verb Runas`
4. pnputil two-step: `/add-driver` to stage INF, then `Add-PrinterDriver` to register
5. Idempotent port creation: `Get-PrinterPort` check before `Add-PrinterPort`
6. Idempotent printer creation: `Get-Printer` check before `Add-Printer`
7. `Set-PrintConfiguration` with translated duplex, color, paper size, collate

## TDD Execution

### RED Phase (commit b4f2c64)

7 tests written in `tests/test_script_generator.py` covering SCRPT-01, SCRPT-04, SCRPT-05. All failed with `ModuleNotFoundError` (confirmed RED).

### GREEN Phase (commit 8193e9d)

- `imptune/generators/script_generator.py` created
- `imptune/templates/scripts/install.ps1.j2` created

One auto-fix required during GREEN: template comment contained `"pnputil.exe"` before the WOW64 `PROCESSOR_ARCHITECTURE` check text, causing the ordering assertion in `test_render_install_wow64_guard` to fail. Fixed by removing `.exe` from the comment text. Not a logic error — purely a textual ordering issue in the rendered output.

All 7 new tests pass. Full suite: 68/68 passing.

## Commits

| Hash | Type | Description |
|------|------|-------------|
| b4f2c64 | test | RED phase — 7 failing tests for script_generator |
| 8193e9d | feat | GREEN phase — script_generator.py + install.ps1.j2 |

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 1 - Bug] Template comment contained 'pnputil.exe' before WOW64 guard text**
- **Found during:** GREEN phase test run
- **Issue:** Comment in the WOW64 guard block header said "pnputil.exe is 64-bit only", so the string "pnputil.exe" appeared in the rendered output before "PROCESSOR_ARCHITECTURE", breaking the ordering assertion in `test_render_install_wow64_guard`
- **Fix:** Changed "pnputil.exe is 64-bit only" to "pnputil is 64-bit only" in the template comment
- **Files modified:** `imptune/templates/scripts/install.ps1.j2`
- **Commit:** 8193e9d (included in same GREEN commit)

## Self-Check: PASSED

All created files verified on disk. All commits verified in git log.

| Item | Status |
|------|--------|
| imptune/generators/script_generator.py | FOUND |
| imptune/templates/scripts/install.ps1.j2 | FOUND |
| tests/test_script_generator.py | FOUND |
| Commit b4f2c64 (RED) | FOUND |
| Commit 8193e9d (GREEN) | FOUND |