---
phase: 03-storage
plan: "03"
subsystem: export
tags: [csv, html, storage, export, utf8-bom, collapsible-tree]

requires:
  - phase: 03-02
    provides: StorageService and StorageNode model with VersionSizeBytes derived property

provides:
  - StorageCsvExportService.BuildCsv — flat UTF-8 BOM CSV with 6-column header
  - StorageHtmlExportService.BuildHtml — self-contained HTML with toggle(i) collapsible tree
  - WriteAsync variants for both exporters

affects:
  - 03-07 (StorageViewModel wires export buttons to these services)
  - 03-08 (StorageView integrates export UX)

tech-stack:
  added: []
  patterns:
    - "RFC 4180 Csv() quoting helper — same pattern as Phase 2 CsvExportService"
    - "HtmlEncode via System.Net.WebUtility.HtmlEncode"
    - "toggle(i) + sf-{i} ID pattern for collapsible HTML rows"
    - "_togIdx counter reset at BuildHtml start for unique IDs per call"
    - "Explicit System.IO using required in WPF project (established pattern)"

key-files:
  created: []
  modified:
    - SharepointToolbox/Services/Export/StorageCsvExportService.cs
    - SharepointToolbox/Services/Export/StorageHtmlExportService.cs

key-decisions:
  - "Explicit System.IO using added to StorageCsvExportService and StorageHtmlExportService — WPF project does not include System.IO in implicit usings (existing project pattern)"

patterns-established:
  - "toggle(i) JS with sf-{i} row IDs for collapsible HTML export — reuse in SearchHtmlExportService (03-05)"

requirements-completed:
  - STOR-04
  - STOR-05

duration: 2min
completed: 2026-04-02
---

# Phase 03 Plan 03: Storage Export Services — CSV and Collapsible-Tree HTML Summary

**StorageCsvExportService (UTF-8 BOM flat CSV) and StorageHtmlExportService (self-contained collapsible-tree HTML) replace stubs — 6 tests pass**

## Performance

- **Duration:** 2 min
- **Started:** 2026-04-02T13:29:04Z
- **Completed:** 2026-04-02T13:30:43Z
- **Tasks:** 2
- **Files modified:** 2

## Accomplishments

- StorageCsvExportService.BuildCsv produces UTF-8 BOM CSV with header row: Library, Site, Files, Total Size (MB), Version Size (MB), Last Modified using RFC 4180 quoting
- StorageHtmlExportService.BuildHtml produces self-contained HTML with inline CSS/JS, toggle(i) function, and collapsible subfolder rows (sf-{i} IDs), ported from PS Export-StorageToHTML
- All 6 tests pass (3 CSV + 3 HTML)

## Task Commits

1. **Task 1: Implement StorageCsvExportService** - `94ff181` (feat)
2. **Task 2: Implement StorageHtmlExportService** - `eafaa15` (feat)

## Files Created/Modified

- `SharepointToolbox/Services/Export/StorageCsvExportService.cs` - Full BuildCsv implementation replacing string.Empty stub
- `SharepointToolbox/Services/Export/StorageHtmlExportService.cs` - Full BuildHtml implementation with collapsible tree rendering

## Decisions Made

- Explicit `System.IO` using added to both files — WPF project does not include System.IO in implicit usings; this is an established project pattern from Phase 1

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 3 - Blocking] Added explicit System.IO using to StorageCsvExportService**
- **Found during:** Task 1 (StorageCsvExportService implementation)
- **Issue:** CS0103 — `File` not found; WPF project lacks System.IO in implicit usings
- **Fix:** Added `using System.IO;` at top of file
- **Files modified:** SharepointToolbox/Services/Export/StorageCsvExportService.cs
- **Verification:** Build succeeded, 3 CSV tests pass
- **Committed in:** `94ff181` (Task 1 commit)

**2. [Rule 3 - Blocking] Added explicit System.IO using to StorageHtmlExportService**
- **Found during:** Task 2 (StorageHtmlExportService implementation)
- **Issue:** Same CS0103 pattern — File.WriteAllTextAsync requires System.IO
- **Fix:** Added `using System.IO;` preemptively before compilation
- **Files modified:** SharepointToolbox/Services/Export/StorageHtmlExportService.cs
- **Verification:** Build succeeded, 3 HTML tests pass
- **Committed in:** `eafaa15` (Task 2 commit)

---

**Total deviations:** 2 auto-fixed (2 blocking — same root cause: WPF project implicit usings)
**Impact on plan:** Both fixes necessary for compilation. No scope creep. Consistent with established project pattern.

## Issues Encountered

The `-x` flag passed in the plan's dotnet test command is not a valid MSBuild switch. Omitting it works correctly — documented for future plans.

## User Setup Required

None - no external service configuration required.

## Next Phase Readiness

- StorageCsvExportService and StorageHtmlExportService ready for use by StorageViewModel (Plan 03-07)
- Both services have WriteAsync variants for file-system output
- No blockers for Wave 2 parallel execution (03-04, 03-06 can proceed independently)

## Self-Check: PASSED

All files and commits verified present.

---
*Phase: 03-storage*
*Completed: 2026-04-02*