# Redundancy Review

## Summary
Kochwas exhibits significant duplication in API endpoint handlers across 22 endpoints, with copy-pasted parameter parsing (parseId/parsePositiveInt) in 8+ files, repeated error-handling patterns in fetch wrappers across 5+ Svelte components, and schema validation blocks that could be consolidated.

## HIGH severity

### Duplicated parseId / parsePositiveInt helpers across API endpoints
- **Sites**: /api/recipes/[id]/+server.ts:51-54, /api/recipes/[id]/favorite/+server.ts:9-13, /api/recipes/[id]/rating/+server.ts:14-18, /api/recipes/[id]/cooked/+server.ts:10-14, /api/recipes/[id]/comments/+server.ts:14-18, /api/profiles/[id]/+server.ts:9-13, /api/domains/[id]/+server.ts:19-23, /api/wishlist/[recipe_id]/+server.ts:9-13
- **Pattern**: Eight API endpoints independently define nearly identical parameter-parsing functions that validate positive integers from route params.
- **Suggestion**: Extract to src/lib/server/api-helpers.ts with parsePositiveIntParam(raw, field) returning the number or throwing via SvelteKit error().

### Copy-pasted fetch error-handling + alert pattern in Svelte components
- **Sites**: /recipes/[id]/+page.svelte:76-87, /recipes/[id]/+page.svelte:253-265, /admin/domains/+page.svelte:31-48, /admin/domains/+page.svelte:67-87, /admin/profiles/+page.svelte:30-44
- **Pattern**: Five component functions repeat identical 6-line blocks: await fetch(); if not ok, parse JSON, show alert with body.message or HTTP status.
- **Suggestion**: Create src/lib/client/api-fetch-wrapper.ts with asyncFetch(url, init, actionTitle) that wraps fetch, error handling, and alertAction.

## MEDIUM severity

### Repeated Zod schema validation + error pattern across API endpoints
- **Sites**: /api/recipes/[id]/+server.ts, /api/recipes/[id]/favorite/+server.ts, /api/recipes/[id]/rating/+server.ts, /api/recipes/[id]/cooked/+server.ts, /api/recipes/[id]/comments/+server.ts, /api/profiles/+server.ts, /api/domains/[id]/+server.ts, /api/wishlist/+server.ts
- **Pattern**: Every endpoint defines schemas locally with safeParse() followed by identical error handling: if not success, error 400 Invalid body. 12+ endpoints repeat this 3-4 line pattern.
- **Suggestion**: Create src/lib/server/schemas.ts with common validators and validateBody<T>(body, schema) helper that centralizes the error throw.

### Recipe scaling / ingredient manipulation scattered without consolidation
- **Sites**: /lib/recipes/scaler.ts:10-16, /lib/server/parsers/ingredient.ts:42-68, /lib/components/RecipeEditor.svelte:144-149, /lib/components/RecipeEditor.svelte:156-175
- **Pattern**: RecipeEditor re-implements parseQty and ingredient assembly (raw_text building) instead of importing parseIngredient from server parser. Logic is nearly identical in two places.
- **Suggestion**: Expose parseIngredient as shared client code or create src/lib/shared/ingredient-utils.ts; import into component to avoid duplication.

### Profile not-selected alert pattern duplicated 4x in same component
- **Sites**: /recipes/[id]/+page.svelte:124-131, :143-150, :166-173, :188-195
- **Pattern**: Four action functions (setRating, toggleFavorite, logCooked, addComment) all open with identical 7-line guard checking active profile and showing same alert message.
- **Suggestion**: Extract requireProfile() helper in src/lib/client/profile.svelte that performs the alert and returns boolean; replace all four guard clauses.

## LOW severity

### WakeLock error handling try-catch pattern
- **Sites**: /recipes/[id]/+page.svelte:318-327, :332-338
- **Pattern**: Both functions independently have try-catch that silently swallows errors. Identical empty catch pattern duplicated.
- **Suggestion**: Cosmetic - document once or combine into manageWakeLock(action) wrapper.

### Migration cache-clearing pattern (historical only)
- **Sites**: /db/migrations/008_thumbnail_cache_drop_unknown.sql, /db/migrations/010_thumbnail_cache_rerun_negatives.sql
- **Pattern**: Two consecutive migrations both DELETE from thumbnail_cache due to feature iteration. Not a bug, just historical stacking.
- **Note**: Safe to leave as-is.

### Test fixture duplication: baseRecipe helper
- **Sites**: /tests/integration/recipe-repository.test.ts:22-42
- **Pattern**: baseRecipe factory defined locally; likely duplicated in other tests.
- **Suggestion**: Move to tests/fixtures/recipe.ts and import everywhere.

### API error message language inconsistency
- **Sites**: /api/recipes/[id]/image/+server.ts (German), all others (English)
- **Pattern**: Image endpoint uses German error messages; all other endpoints use English.
- **Suggestion**: Standardize to German or English for consistent UX.

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## Notes

Strong separation of concerns observed in repositories and parsers. Type definitions well-centralized in src/lib/types.ts. No major SQL redundancy beyond historical migrations. Primary improvement opportunities are parameter validation, error handling, and component fetch logic consolidation.