---
phase: 09-storage-visualization
plan: 01
subsystem: storage-visualization
tags: [nuget, data-model, interface, livecharts2]
dependency_graph:
  requires: []
  provides: [LiveChartsCore.SkiaSharpView.WPF, FileTypeMetric, CollectFileTypeMetricsAsync]
  affects: [StorageService, StorageVisualization]
tech_stack:
  added: [LiveChartsCore.SkiaSharpView.WPF 2.0.0-rc5.4, SkiaSharp 3.116.1]
  patterns: [record-type-model, interface-extension]
key_files:
  created:
    - SharepointToolbox/Core/Models/FileTypeMetric.cs
  modified:
    - SharepointToolbox/SharepointToolbox.csproj
    - SharepointToolbox/Services/IStorageService.cs
decisions:
  - LiveCharts2 RC5.4 with SkiaSharp WPF backend chosen for self-contained EXE compatibility
  - FileTypeMetric uses record type matching existing model conventions (StorageScanOptions, OperationProgress)
  - CollectFileTypeMetricsAsync omits StorageScanOptions parameter since file-type scan covers all non-hidden libraries
metrics:
  duration: 1 min
  completed: 2026-04-07
---

# Phase 09 Plan 01: LiveCharts2, FileTypeMetric Model, and IStorageService Extension Summary

LiveCharts2 SkiaSharp WPF NuGet added, FileTypeMetric record created with Extension/TotalSizeBytes/FileCount/DisplayLabel, IStorageService extended with CollectFileTypeMetricsAsync returning IReadOnlyList<FileTypeMetric>.

## Tasks Completed

| Task | Name | Commit | Key Files |
|------|------|--------|-----------|
| 1 | Add LiveCharts2 NuGet and FileTypeMetric model | 60cbb97 | SharepointToolbox.csproj, FileTypeMetric.cs |
| 2 | Extend IStorageService with CollectFileTypeMetricsAsync | 39c31da | IStorageService.cs |

## Verification Results

- LiveChartsCore.SkiaSharpView.WPF 2.0.0-rc5.4 appears in csproj PackageReference
- FileTypeMetric.cs exists in Core/Models with record definition (Extension, TotalSizeBytes, FileCount, DisplayLabel)
- IStorageService.cs has both CollectStorageAsync (unchanged) and CollectFileTypeMetricsAsync (new)
- Build compiles with 0 errors after Task 1; CS0535 after Task 2 is expected (StorageService implementation deferred to Plan 09-02)
- NU1701 warnings for OpenTK/SkiaSharp.Views.WPF framework compatibility are non-blocking

## Deviations from Plan

None - plan executed exactly as written.

## Decisions Made

1. **LiveCharts2 version 2.0.0-rc5.4**: Pre-release RC installed with explicit version flag; no --prerelease fallback needed
2. **FileTypeMetric as record type**: Matches existing model patterns (StorageScanOptions, OperationProgress) for value semantics
3. **CollectFileTypeMetricsAsync without StorageScanOptions**: Scans all non-hidden document libraries without folder depth/subsites filtering

## Notes

- NU1701 warnings from OpenTK and SkiaSharp.Views.WPF are expected when targeting net10.0-windows; these packages use .NET Framework fallback but function correctly at runtime
- CS0535 error is expected and will be resolved in Plan 09-02 when StorageService implements CollectFileTypeMetricsAsync

## Self-Check: PASSED

- All 3 files verified present on disk
- Both commits (60cbb97, 39c31da) verified in git log
- LiveChartsCore.SkiaSharpView.WPF in csproj: confirmed
- CollectFileTypeMetricsAsync in IStorageService.cs: confirmed
- record FileTypeMetric in FileTypeMetric.cs: confirmed