SimpleFinanceDash/.planning/phases/05-template-data-model-and-api/05-02-SUMMARY.md

phase, plan, subsystem, tags, requires, provides, affects, tech-stack, key-files, key-decisions, duration, completed

phase	plan	subsystem	tags	requires	provides	affects	tech-stack	key-files	key-decisions	duration	completed
05-template-data-model-and-api	02	api	go rest-api templates budget-generation http-handlers	phase plan provides 05-template-data-model-and-api 01 GetTemplate, CreateTemplateItem, UpdateTemplateItem, DeleteTemplateItem, ReorderTemplateItems, GenerateBudgetFromTemplate, BudgetExistsError	GET /api/template returns TemplateDetail (empty items when no template) PUT /api/template updates template name POST /api/template/items adds template item with validation (no one_off, fixed requires budgeted_amount) PUT /api/template/items/{itemId} updates template item DELETE /api/template/items/{itemId} removes template item (204) PUT /api/template/items/reorder batch-updates sort order (204) POST /api/budgets/generate creates budget from template or returns 409 with budget_id CreateBudgetItem/UpdateBudgetItem handlers already accept item_tier (done in Plan 01 auto-fix)	06 (frontend template UI will call these endpoints)	added patterns errors.As for typed BudgetExistsError detection in GenerateBudget handler Static route /items/reorder registered before parameterized /items/{itemId} for correct chi routing Handler-level validation mirrors DB CHECK constraint as defense in depth	created modified backend/internal/api/handlers.go backend/internal/api/router.go	PUT /items/reorder registered before PUT /items/{itemId} to prevent chi treating 'reorder' as an itemId GenerateBudget returns 409 JSON with both error message and budget_id field using BudgetExistsError.ExistingBudgetID Handler validates month format via time.Parse before calling query layer (redundant but explicit)	1min	2026-03-12

Phase 5 Plan 2: Template API Handlers Summary

HTTP handlers and routes for template CRUD, item reorder, and budget-from-template generation wired to the query layer built in Plan 01

Performance

• Duration: ~1 min
• Started: 2026-03-12T11:09:32Z
• Completed: 2026-03-12T11:10:40Z
• Tasks: 2
• Files modified: 2

Accomplishments

• All 7 template handler methods added to handlers.go: GetTemplate, UpdateTemplateName, CreateTemplateItem, UpdateTemplateItem, DeleteTemplateItem, ReorderTemplateItems, GenerateBudget
• Handler-level validation for template items: one_off tier rejected with 400, fixed tier requires budgeted_amount
• GenerateBudget uses errors.As to detect BudgetExistsError and returns structured 409 with budget_id
• /api/template route group fully wired in router.go with correct static-before-param ordering for /items/reorder vs /items/{itemId}
• POST /api/budgets/generate placed before /{id} routes to avoid "generate" being parsed as a budget ID
• Full backend builds and vets clean

Task Commits

Each task committed atomically:

1. Task 1: Template handlers and budget generation handler - ceca2fc (feat)
2. Task 2: Wire routes in router.go - 387507b (feat)

Files Created/Modified

• backend/internal/api/handlers.go - Added 7 new handler methods, added errors import
• backend/internal/api/router.go - Added /api/template route group and POST /api/budgets/generate

Decisions Made

• PUT /items/reorder registered before PUT /items/{itemId} — chi matches static routes first when registered in order; this prevents "reorder" being treated as an itemId parameter
• GenerateBudget returns JSON body {"error": "budget already exists", "budget_id": "..."} on 409 — uses BudgetExistsError.ExistingBudgetID (field name established in Plan 01)
• UpdateTemplateName handler returns 404 for any error — since lazy creation means the only failure mode before an item exists is "no template", and connection errors are rare; consistent with UpdateCategory pattern

Deviations from Plan

None - plan executed exactly as written. The budget item handler updates (item_tier pass-through) were already done in Plan 01's auto-fix, so Task 1 focused entirely on new template handlers.

Issues Encountered

None.

User Setup Required

None - no external service configuration required. Routes are live after next server start.

Next Phase Readiness

• All REST endpoints for Phase 6 (template UI) are available
• API contract is stable: GET returns empty items array (not error) when no template exists
• 409 conflict response includes budget_id so frontend can navigate to existing budget

Self-Check: PASSED

Both modified files verified on disk. Both task commits (ceca2fc, 387507b) present in git log. go build ./... and go vet ./... pass clean.

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Phase: 05-template-data-model-and-api Completed: 2026-03-12