---
phase: 15-consolidation-data-model
plan: "01"
subsystem: api
tags: [csharp, records, linq, permission-consolidation]

requires: []
provides:
  - LocationInfo record with five location fields (SiteUrl, SiteTitle, ObjectTitle, ObjectUrl, ObjectType)
  - ConsolidatedPermissionEntry record grouping key fields with IReadOnlyList<LocationInfo> Locations
  - PermissionConsolidator.Consolidate — pure static method merging UserAccessEntry list by composite key
  - PermissionConsolidator.MakeKey — pipe-delimited case-insensitive key from UserLogin+PermissionLevel+AccessType+GrantedThrough
affects: [16-report-consolidation-toggle]

tech-stack:
  added: []
  patterns:
    - "Positional C# records for immutable data shapes"
    - "LINQ GroupBy+Select for pure-function merge without mutable state"
    - "Internal MakeKey for composite key generation (pipe-delimited, ToLowerInvariant)"
    - "Array.Empty<T>() short-circuit on empty input"

key-files:
  created:
    - SharepointToolbox/Core/Models/LocationInfo.cs
    - SharepointToolbox/Core/Models/ConsolidatedPermissionEntry.cs
    - SharepointToolbox/Core/Helpers/PermissionConsolidator.cs
  modified: []

key-decisions:
  - "MakeKey is internal (not private) to allow test access via InternalsVisibleTo without exposing as public API"
  - "LINQ GroupBy+Select chosen over mutable Dictionary to match existing codebase functional style"
  - "OrderBy UserLogin then PermissionLevel ensures deterministic output order for consistent exports"

patterns-established:
  - "Consolidation key: pipe-delimited lowercase composite of UserLogin|PermissionLevel|AccessType|GrantedThrough"
  - "LocationInfo is the extraction unit — one per original UserAccessEntry row in a consolidated group"

requirements-completed: [RPT-04]

duration: 1min
completed: "2026-04-09"
---

# Phase 15 Plan 01: Consolidation Data Model Summary

**LocationInfo + ConsolidatedPermissionEntry records and PermissionConsolidator.Consolidate pure-function merge service using LINQ GroupBy over pipe-delimited composite key**

## Performance

- **Duration:** ~1 min
- **Started:** 2026-04-09T09:40:40Z
- **Completed:** 2026-04-09T09:41:37Z
- **Tasks:** 2
- **Files modified:** 3

## Accomplishments

- LocationInfo positional record extracts five location fields from UserAccessEntry during consolidation
- ConsolidatedPermissionEntry record holds key fields plus computed LocationCount convenience property
- PermissionConsolidator.Consolidate groups a flat UserAccessEntry list by (UserLogin, PermissionLevel, AccessType, GrantedThrough) composite key, returning deterministically ordered consolidated rows
- Empty input short-circuits cleanly to Array.Empty without allocating

## Task Commits

Each task was committed atomically:

1. **Task 1: Create LocationInfo and ConsolidatedPermissionEntry model records** - `270329b` (feat)
2. **Task 2: Create PermissionConsolidator static helper** - `440b247` (feat)

## Files Created/Modified

- `SharepointToolbox/Core/Models/LocationInfo.cs` - Lightweight record holding five location fields extracted from UserAccessEntry when rows are merged
- `SharepointToolbox/Core/Models/ConsolidatedPermissionEntry.cs` - Consolidated permission record with key fields, Locations list, and computed LocationCount property
- `SharepointToolbox/Core/Helpers/PermissionConsolidator.cs` - Static helper with MakeKey (internal) and Consolidate (public) for pure-function merge logic

## Decisions Made

- `MakeKey` declared `internal` (not `private`) so test projects can access it via `[InternalsVisibleTo]` without exposing as public API surface
- LINQ GroupBy+Select pattern used instead of mutable dictionary — consistent with functional style seen elsewhere in the codebase
- Output ordered by UserLogin then PermissionLevel for deterministic, predictable export row ordering

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered

None.

## User Setup Required

None - no external service configuration required.

## Next Phase Readiness

- Phase 16 (Report Consolidation Toggle) can now wire PermissionConsolidator.Consolidate into the export pipeline
- All three files exist, compile without errors, and no existing files were modified
- MakeKey is accessible to Phase 16 test projects via InternalsVisibleTo if needed

---
*Phase: 15-consolidation-data-model*
*Completed: 2026-04-09*