# Proposal: Remove Unnecessary Normalizers

## Problem

We have unnecessary abstraction layers that convert between identical data structures multiple times:

```
Frontend State → build*Selections() → OrderSelections → toSearchParams() 
  → URLSearchParams → paramsToRecord() → normalizeSelections() → OrderSelections → BFF
```

## Unnecessary Functions to Remove

### 1. `packages/domain/orders/checkout.ts`

**Remove these:**
- `buildInternetCheckoutSelections()` - Lines 103-129
- `deriveInternetCheckoutState()` - Lines 134-156
- `buildSimCheckoutSelections()` - Lines 161-216
- `deriveSimCheckoutState()` - Lines 221-282
- `coalescePlanSku()` - Lines 81-97 (now obsolete after plan/planSku cleanup)
- `normalizeString()` - Lines 56-60
- `normalizeSkuList()` - Lines 62-71
- `parseAddonList()` - Lines 73-79
- All Draft/Patch interfaces - Lines 10-54

**Keep:**
- Nothing from this file is needed in domain layer

### 2. `apps/portal/src/features/catalog/services/catalog.store.ts`

**Simplify:**
- `buildInternetCheckoutParams()` - Lines 202-217
- `buildSimCheckoutParams()` - Lines 219-238
- `selectionsToSearchParams()` - Lines 124-136
- `paramsToSelectionRecord()` - Lines 114-122

**Replace with:** Direct URL param construction from state

## What Frontend Should Do Instead

### For Internet Checkout:

```typescript
// BEFORE (current mess):
const selections = buildInternetCheckoutSelections({
  planSku: internet.planSku,
  accessMode: internet.accessMode,
  installationSku: internet.installationSku,
  addonSkus: internet.addonSkus,
});
return selectionsToSearchParams(selections, "internet");

// AFTER (clean):
const params = new URLSearchParams({
  type: "internet",
  planSku: internet.planSku,
  accessMode: internet.accessMode,
  installationSku: internet.installationSku,
  addons: internet.addonSkus.join(","), // Only transform is array → CSV
});
return params;
```

### For SIM Checkout:

```typescript
// BEFORE:
const selections = buildSimCheckoutSelections({...});
return selectionsToSearchParams(selections, "sim");

// AFTER:
const params = new URLSearchParams();
params.set("type", "sim");
params.set("planSku", sim.planSku);
if (sim.simType) params.set("simType", sim.simType);
// ... only add non-empty values
return params;
```

### For Restoring from Params:

```typescript
// BEFORE:
const selections = normalizeOrderSelections(paramsToSelectionRecord(params));
const derived = deriveInternetCheckoutState(selections);
set({ internet: { ...state.internet, ...derived } });

// AFTER:
set({
  internet: {
    planSku: params.get("planSku") ?? undefined,
    accessMode: params.get("accessMode") ?? undefined,
    installationSku: params.get("installationSku") ?? undefined,
    addonSkus: params.get("addons")?.split(",") ?? [],
  }
});
```

## Benefits

1. **Fewer lines of code** - Remove ~300+ lines
2. **Clearer data flow** - No mysterious transformations
3. **Better type safety** - Direct property access, not dynamic string manipulation
4. **Easier debugging** - Fewer layers to trace through
5. **Frontend owns frontend data** - Domain layer isn't polluted with UI concerns

## What Domain Layer SHOULD Have

Only these helpers:
- `normalizeOrderSelections(value: unknown): OrderSelections` - Zod validation from API/params
- `buildOrderConfigurations(selections: OrderSelections): OrderConfigurations` - Extract config from selections

That's it! Frontend handles its own URL param serialization.

## Migration Plan

1. Update catalog store to directly build URL params
2. Update checkout param service to directly parse params
3. Remove all build/derive functions from domain
4. Remove Draft/Patch interfaces
5. Test all checkout flows (Internet, SIM, VPN)

## Files to Change

### Remove entirely:
- Most of `packages/domain/orders/checkout.ts` (keep only types if needed)

### Simplify:
- `apps/portal/src/features/catalog/services/catalog.store.ts`
- `apps/portal/src/features/checkout/services/checkout-params.service.ts`

### Update imports in:
- `apps/portal/src/features/catalog/hooks/useInternetConfigure.ts`
- `apps/portal/src/features/catalog/hooks/useSimConfigure.ts`
- Any component using these functions