# Hotfix: Add Customer Sub Group to Customer Form

## Goal

เพิ่ม field `Customer Sub Group` ในหน้า Add / Edit Customer

โดยใช้ master option category:

```txt
crm_customer_sub_group
```

และต้อง filter ตาม `Customer Group` ที่เลือก

Relationship:

```txt
crm_customer_group
  ↓ parent
crm_customer_sub_group
```

---

## Must Read

```txt
src/features/crm/customers/**
src/features/foundation/master-options/**
src/app/api/foundation/master-options/route.ts
src/db/schema.ts
src/db/seeds/foundation.seed.ts
```

---

## Scope 1: Data Model Check

ตรวจสอบว่า customer schema มี field สำหรับ sub group แล้วหรือยัง

Expected field:

```txt
customerSubGroup
```

หรือถ้าใช้ naming เดิม:

```txt
custSubGroup
```

Rules:

* ถ้ามี field อยู่แล้ว ให้ reuse
* ถ้ายังไม่มี ให้เพิ่ม field ใหม่แบบไม่กระทบข้อมูลเดิม
* field เป็น optional
* เก็บเป็น master option code/value ตาม pattern เดิมของ customerGroup

---

## Scope 2: Master Option Category

เพิ่ม/ยืนยัน category:

```txt
crm_customer_sub_group
```

Sub group ต้องมี parent relationship กับ group:

```txt
crm_customer_group.id
  ↓
crm_customer_sub_group.parentId
```

Rules:

* parentId ต้องชี้ไป customer group option
* sub group dropdown ต้อง filter ด้วย parentId
* ถ้ายังไม่ได้เลือก customer group ให้ disable sub group dropdown

---

## Scope 3: Seed Data

อัปเดต:

```txt
src/db/seeds/foundation.seed.ts
```

เพิ่ม seed category:

```txt
crm_customer_group
crm_customer_sub_group
```

ตัวอย่าง:

```txt
crm_customer_group:
- industrial
- construction
- government
- dealer
- other

crm_customer_sub_group:
- factory
- warehouse
- logistics
- contractor
- consultant
- state_enterprise
- government_agency
- reseller
- other
```

Relationship ตัวอย่าง:

```txt
industrial
  - factory
  - warehouse
  - logistics

construction
  - contractor
  - consultant

government
  - state_enterprise
  - government_agency

dealer
  - reseller

other
  - other
```

Rules:

* seed idempotent
* no hardcoded organizationId
* parent option must be created before child options
* child options must set parentId
* do not duplicate options if seed runs again

---

## Scope 4: Customer Schema / Zod

Update:

```txt
src/features/crm/customers/schemas/customer.schema.ts
```

Add:

```ts
customerSubGroup: z.string().optional().nullable()
```

หรือใช้ field name ที่มีอยู่จริง เช่น:

```ts
custSubGroup: z.string().optional().nullable()
```

Rules:

* Create Customer ต้องรับ field นี้ได้
* Edit Customer ต้อง load ค่าเดิมได้
* ถ้าเปลี่ยน customerGroup แล้ว customerSubGroup ไม่อยู่ใต้ parent ใหม่ ให้ clear ค่า customerSubGroup

---

## Scope 5: API / Server Service

Update:

```txt
src/features/crm/customers/server/service.ts
src/app/api/crm/customers/route.ts
src/app/api/crm/customers/[id]/route.ts
src/features/crm/customers/api/types.ts
```

Rules:

* create customer save customerSubGroup
* update customer save customerSubGroup
* list/detail return customerSubGroup
* validate sub group parent matches selected group ถ้าทำได้ง่าย
* if invalid parent-child relation, return user-safe error

---

## Scope 6: Customer Form UI

Update:

```txt
src/features/crm/customers/components/customer-form-sheet.tsx
```

Add field:

```txt
Customer Group
Customer Sub Group
```

Behavior:

* Customer Group dropdown uses `crm_customer_group`
* Customer Sub Group dropdown uses `crm_customer_sub_group`
* Customer Sub Group filtered by selected group option `parentId`
* If no Customer Group selected:

  * disable Customer Sub Group
  * placeholder: "Select customer group first"
* If Customer Group changes:

  * reset Customer Sub Group
* If edit mode:

  * load existing Customer Group
  * load filtered Customer Sub Group
  * selected value must display correctly

---

## Scope 7: Customer List / Detail

Update if relevant:

```txt
src/features/crm/customers/components/customer-columns.tsx
src/features/crm/customers/components/customer-detail.tsx
```

Display:

```txt
Customer Group
Customer Sub Group
```

If label lookup is available, show label instead of raw code.

---

## Scope 8: Query Freshness

After create/update:

* invalidate customer list
* invalidate customer detail
* form closes after success
* table/detail show new customer sub group immediately

Follow existing CRUD freshness rule.

---

## Scope 9: Regression Check

Verify:

* create customer with group + sub group
* create customer without sub group
* edit customer group changes and sub group resets
* edit customer retains valid sub group
* invalid sub group under another group is rejected or cleared
* customer list/detail displays value

---

## Explicit Non-Scope

Do NOT implement:

```txt
Customer group management UI
Inline create master option
Large RBAC rewrite
Customer import/export
Dashboard changes
Report changes
```

---

## Output

After completion, summarize:

1. Files Added
2. Files Modified
3. Schema Field Used/Added
4. Master Options Seeded
5. Form Behavior Added
6. Parent/Child Filtering Behavior
7. Validation Added
8. Verification Result
9. Remaining Risks

---

## Definition of Done

* Add/Edit Customer has Customer Sub Group field
* Customer Sub Group uses `crm_customer_sub_group`
* Sub Group filters by selected Customer Group parent
* Changing Customer Group resets invalid Sub Group
* Create customer saves Sub Group
* Edit customer saves Sub Group
* Detail/list can show Sub Group
* Mutation refreshes customer table/detail