---
phase: 16-report-consolidation-toggle
plan: "01"
subsystem: export
tags: [csv-export, consolidation, viewmodel, xaml, localization, tdd]
dependency-graph:
  requires: [15-01, 15-02]
  provides: [MergePermissions toggle UI, consolidated CSV export path]
  affects: [UserAccessAuditViewModel, PermissionsViewModel, UserAccessCsvExportService]
tech-stack:
  added: []
  patterns: [ObservableProperty, XAML GroupBox binding, optional parameter default, early-return branch, TDD red-green]
key-files:
  created: []
  modified:
    - SharepointToolbox/ViewModels/Tabs/UserAccessAuditViewModel.cs
    - SharepointToolbox/ViewModels/Tabs/PermissionsViewModel.cs
    - SharepointToolbox/Views/Tabs/UserAccessAuditView.xaml
    - SharepointToolbox/Views/Tabs/PermissionsView.xaml
    - SharepointToolbox/Localization/Strings.resx
    - SharepointToolbox/Localization/Strings.fr.resx
    - SharepointToolbox/Services/Export/UserAccessCsvExportService.cs
    - SharepointToolbox.Tests/Services/Export/UserAccessCsvExportServiceTests.cs
decisions:
  - "Consolidated branch uses early-return pattern inside WriteSingleFileAsync to leave existing code path completely untouched"
  - "PermissionsViewModel gets MergePermissions as a no-op placeholder — PermissionsViewModel uses a different export service (CsvExportService, not UserAccessCsvExportService) so the property is reserved for future use"
  - "Export Options GroupBox placed after Scan Options in UserAccessAuditView and after Display Options in PermissionsView — keeps related configuration grouped"
metrics:
  duration: ~15min
  completed: 2026-04-09
  tasks: 3
  files-modified: 8
---

# Phase 16 Plan 01: MergePermissions Toggle UI + Consolidated CSV Export Summary

MergePermissions ObservableProperty on both ViewModels, Export Options GroupBox in both XAML tabs, localized EN/FR strings, and consolidated CSV export path using PermissionConsolidator.

## Tasks Completed

| Task | Name | Commit | Files |
|------|------|--------|-------|
| 1 | Add MergePermissions property to both ViewModels and localization keys | ed9f149 | UserAccessAuditViewModel.cs, PermissionsViewModel.cs, Strings.resx, Strings.fr.resx |
| 2 | Add Export Options GroupBox to both XAML views | db42047 | UserAccessAuditView.xaml, PermissionsView.xaml |
| 3 (RED) | Add failing tests for RPT-03-f and RPT-03-g | 4f7a6e3 | UserAccessCsvExportServiceTests.cs |
| 3 (GREEN) | Implement consolidated CSV export path and wire ViewModel call site | 28714fb | UserAccessCsvExportService.cs, UserAccessAuditViewModel.cs |

## What Was Built

### MergePermissions Property
- `UserAccessAuditViewModel`: `[ObservableProperty] private bool _mergePermissions;` — defaults false, no partial handler needed
- `PermissionsViewModel`: same property as a no-op placeholder (PermissionsViewModel uses `CsvExportService`, not `UserAccessCsvExportService`)

### Localization
- `audit.grp.export` — "Export Options" / "Options d'exportation"
- `chk.merge.permissions` — "Merge duplicate permissions" / "Fusionner les permissions en double"

### XAML GroupBoxes
Both views received an "Export Options" GroupBox with a single checkbox bound to `MergePermissions`. The groupbox is always visible (never conditionally hidden). Existing XAML elements are untouched.

### Consolidated CSV Export
`WriteSingleFileAsync` now accepts `bool mergePermissions = false`. When true:
1. Calls `PermissionConsolidator.Consolidate(entries)` to merge rows sharing the same (UserLogin, PermissionLevel, AccessType, GrantedThrough) key
2. Writes a consolidated CSV with header: `"User","User Login","Permission Level","Access Type","Granted Through","Locations","Location Count"`
3. Locations column = semicolon-separated `SiteTitle` values from all merged locations
4. Returns early — existing code path below is completely untouched

`UserAccessAuditViewModel.ExportCsvAsync` now passes `MergePermissions` to the service.

### Tests (TDD)
3 new test methods covering RPT-03-f and RPT-03-g:
- `WriteSingleFileAsync_mergePermissionsfalse_produces_identical_output` — byte-identical to default call
- `WriteSingleFileAsync_mergePermissionstrue_writes_consolidated_rows` — consolidated header + merged rows
- `WriteSingleFileAsync_mergePermissionstrue_singleLocation_noSemicolon` — single location has LocationCount=1

All 8 UserAccessCsvExportServiceTests pass.

## Decisions Made

1. **Early-return consolidated branch** — Plan specified leaving existing code path untouched. Added `if (mergePermissions) { ... return; }` before the existing `var sb = new StringBuilder()` block. The existing block is wrapped in an anonymous `{}` scope for clarity but behavior is unchanged.

2. **PermissionsViewModel as no-op placeholder** — The Permissions tab uses `CsvExportService` (not `UserAccessCsvExportService`), so `MergePermissions` cannot be wired to export logic in this plan. The property is added for XAML binding completeness and future implementation.

3. **GroupBox placement** — Export Options placed immediately before the Run/Export buttons in UserAccessAuditView, and before Action buttons in PermissionsView. This keeps export-related options adjacent to export buttons.

## Verification Results

- `dotnet build` — 0 errors, 0 warnings
- `dotnet test --filter "FullyQualifiedName~UserAccessCsvExportServiceTests"` — 8/8 passed
- `dotnet test` full suite — 296 passed, 26 skipped, 2 flaky timing failures (pre-existing debounce tests, pass when run individually)

## Deviations from Plan

None — plan executed exactly as written.

## Self-Check: PASSED

Files exist:
- SharepointToolbox/ViewModels/Tabs/UserAccessAuditViewModel.cs — contains `_mergePermissions`
- SharepointToolbox/ViewModels/Tabs/PermissionsViewModel.cs — contains `_mergePermissions`
- SharepointToolbox/Views/Tabs/UserAccessAuditView.xaml — contains `Export Options`
- SharepointToolbox/Views/Tabs/PermissionsView.xaml — contains `Export Options`
- SharepointToolbox/Services/Export/UserAccessCsvExportService.cs — contains `mergePermissions`
- SharepointToolbox.Tests/Services/Export/UserAccessCsvExportServiceTests.cs — 3 new test methods

Commits exist: ed9f149, db42047, 4f7a6e3, 28714fb