mal/plans/010-add-watchlist-import-restore.md

finding, catalog, impact, base_commit

finding	catalog	impact	base_commit
Add watchlist import / restore	Direction	Local-first users can export watchlist state but cannot round-trip it into a new install or after data loss.	0d31d46

Effort

M - server-side CSV parsing, validation, UI, and service tests.

Risk

MED - import needs careful duplicate handling, status validation, and partial-failure reporting.

Confidence

HIGH - export exists and the inverse capability is missing.

Evidence

• templates/watchlist.gohtml:18 exposes an “Export to CSV” action.
• static/watchlist.ts:317-343 implements CSV export from rendered watchlist rows.
• internal/watchlist/handler.go:21-25 registers update, delete, continue-watching delete, and page routes, but no import route.

Resolution Approach

Treat this as a product/design implementation plan, not a bug fix. Define the import contract to match the existing export columns: mal_id, title, status, and updated_at. The server should validate mal_id and supported status values, ignore or display title only as user context, and decide whether updated_at is informational or preserved.

Prefer a dry-run or preview step before mutation. The preview should report valid rows, duplicates, unknown statuses, malformed IDs, and rows that would update existing entries. The final apply step should upsert valid watchlist entries for the current authenticated user and return row-level results.

Add service and handler tests for valid import, duplicate rows, invalid statuses, malformed CSV, empty files, and partial success. Keep import scoped to watchlist entries; do not attempt to restore playback progress or continue-watching state unless a separate plan expands the export schema.

Verify with go test ./internal/watchlist ./..., bunx tsc -p tsconfig.json --noEmit, and bun run lint:ts if frontend UI is added.