---
phase: 03-setups-and-dashboard
plan: 01
subsystem: api
tags: [drizzle, hono, sqlite, junction-table, tdd]

requires:
  - phase: 01-collection-core
    provides: items table, categories table, item service pattern, route pattern, test helper
provides:
  - Setup CRUD API at /api/setups
  - Junction table setup_items (many-to-many items-to-setups)
  - SQL aggregation for setup totals (weight, cost, item count)
  - syncSetupItems for batch item assignment
affects: [03-02-setup-frontend, 03-03-dashboard]

tech-stack:
  added: []
  patterns: [junction-table-with-cascade, sql-coalesce-aggregation, delete-all-reinsert-sync]

key-files:
  created:
    - src/server/services/setup.service.ts
    - src/server/routes/setups.ts
    - tests/services/setup.service.test.ts
    - tests/routes/setups.test.ts
  modified:
    - src/db/schema.ts
    - src/shared/schemas.ts
    - src/shared/types.ts
    - src/server/index.ts
    - tests/helpers/db.ts

key-decisions:
  - "syncSetupItems uses delete-all + re-insert in transaction for simplicity over diff-based sync"
  - "SQL COALESCE ensures 0 returned for empty setups instead of null"

patterns-established:
  - "Junction table pattern: cascade deletes on both FK sides for clean removal"
  - "Sync pattern: transactional delete-all + re-insert for many-to-many updates"

requirements-completed: [SETP-01, SETP-02, SETP-03]

duration: 8min
completed: 2026-03-15
---

# Phase 3 Plan 1: Setup Backend Summary

**Setup CRUD API with junction table, SQL aggregation for totals, and transactional item sync**

## Performance

- **Duration:** 8 min
- **Started:** 2026-03-15T11:35:17Z
- **Completed:** 2026-03-15T11:43:11Z
- **Tasks:** 2 (TDD RED + GREEN)
- **Files modified:** 9

## Accomplishments
- Setup CRUD with all 7 API endpoints working
- Junction table (setup_items) with cascade deletes on both setup and item deletion
- SQL aggregation returning itemCount, totalWeight, totalCost via COALESCE subqueries
- Full TDD with 24 new tests (13 service + 11 route), all 87 tests passing

## Task Commits

Each task was committed atomically:

1. **Task 1: RED - Failing tests + schema** - `1e4e74f` (test)
2. **Task 2: GREEN - Implementation** - `0f115a2` (feat)

## Files Created/Modified
- `src/db/schema.ts` - Added setups and setupItems table definitions
- `src/shared/schemas.ts` - Added createSetupSchema, updateSetupSchema, syncSetupItemsSchema
- `src/shared/types.ts` - Added CreateSetup, UpdateSetup, SyncSetupItems, Setup, SetupItem types
- `src/server/services/setup.service.ts` - Setup business logic with DB injection
- `src/server/routes/setups.ts` - Hono API routes for all 7 setup endpoints
- `src/server/index.ts` - Mounted setupRoutes at /api/setups
- `tests/helpers/db.ts` - Added setups and setup_items CREATE TABLE statements
- `tests/services/setup.service.test.ts` - 13 service unit tests
- `tests/routes/setups.test.ts` - 11 route integration tests

## Decisions Made
- syncSetupItems uses delete-all + re-insert in transaction for simplicity over diff-based sync
- SQL COALESCE ensures 0 returned for empty setups instead of null
- removeSetupItem uses raw SQL WHERE clause for compound condition (setupId + itemId)

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered

None

## User Setup Required

None - no external service configuration required.

## Next Phase Readiness
- Setup API complete and tested, ready for frontend consumption in Plan 02
- Junction table pattern established for any future many-to-many relationships

---
*Phase: 03-setups-and-dashboard*
*Completed: 2026-03-15*