update readme

README.md

@@ -1,14 +1,106 @@
 # be-accone
 
-## Generate payment instruction cicilan
-### curl command
-`
+Backend service for Accone.
+
+---
+
+## Generate Monthly Installments (Cicilan Aset)
+
+Automatically creates `supplier_installment` rows for all eligible active contracts every month. This is designed to be executed via **CRON daily at 1:00 AM**.
+
+> **Note:** No journal entries are created here — that happens at cashier payment time. The contract's `InstallmentPaid` field is also **not** updated here — it's updated when payment is received.
+
+### Endpoint
+
+```
+POST /one-api/mockup/scheduler/PurchaseInvoiceInstallment/GenerateMonthlyInvoices
+```
+
+### Request
+
+| Field         | Value              |
+|---------------|--------------------|
+| **Method**    | `POST`             |
+| **Content-Type** | `application/json` |
+| **Body**      | `{}` (optional `startDate` / `endDate`) |
+
+```bash
 curl -s -X POST "https://accone.aplikasi.web.id/one-api/mockup/scheduler/PurchaseInvoiceInstallment/GenerateMonthlyInvoices" \
      -H "Content-Type: application/json" \
      -d '{}'
-`
+```
 
-### response 
-`
-{"status":"OK","data":{"startDate":"2026-07-01","endDate":"2026-07-31","totalEligible":1,"totalInserted":1,"created":[{"installmentID":6,"contractID":"11","purchaseOrderID":"20","parentInvoiceID":"16","parentInvoiceNumber":"PI-016\/SDM-14\/SM-1\/VII\/2026","amount":5000000,"installDate":"2026-07-22","dueDate":"2026-07-29"}]}}
-`
+**Optional body parameters:**
+
+```json
+{
+  "startDate": "2026-07-01",
+  "endDate": "2026-07-31"
+}
+```
+
+If omitted, defaults to the current month (`startDate` = first day, `endDate` = last day).
+
+### Eligibility Logic (Steps 1–5)
+
+A contract is eligible for installment generation only if **all** of the following conditions are met:
+
+| Step | Condition |
+|------|-----------|
+| **1** | Contract is **active** (`IsActive = 'Y'`), status is **"belum lunas"**, has a positive `InstallmentPayAmount`, `InstallmentPaid < InstallmentNumber`, falls within the date range, and the scheduled day of month has been reached |
+| **2** | Associated **Purchase Order** is **Approved** and **Active** |
+| **3** | Associated **Receive Order** is **Confirmed** and **Active** |
+| **4** | A parent **Supplier Invoice** exists with `IsInstallment = 'Y'` |
+| **5** | No `supplier_installment` record already exists for the same PO in the same month |
+
+### Step 6 — Insert
+
+For each eligible contract, a row is inserted into `supplier_installment` with:
+
+- `SupplierInstallmentStatus` = `"Pending"`
+- `SupplierInstallmentIsLunas` = `"N"`
+- `SupplierInstallmentDate` = the contract's scheduled day of month (capped to the last day of the month)
+- `SupplierInstallmentDueDate` = same as InstallmentDate, can be changed at payment instrutions manu
+
+### Response
+
+```json
+{
+  "status": "OK",
+  "data": {
+    "startDate": "2026-07-01",
+    "endDate": "2026-07-31",
+    "totalEligible": 1,
+    "totalInserted": 1,
+    "created": [
+      {
+        "installmentID": 6,
+        "contractID": "11",
+        "purchaseOrderID": "20",
+        "parentInvoiceID": "16",
+        "parentInvoiceNumber": "PI-016/SDM-14/SM-1/VII/2026",
+        "amount": 5000000,
+        "installDate": "2026-07-22",
+        "dueDate": "2026-07-22"
+      }
+    ]
+  }
+}
+```
+
+| Field | Type | Description |
+|-------|------|-------------|
+| `status` | `string` | `"OK"` on success |
+| `data.startDate` | `string` | Start of the billing period (`YYYY-MM-DD`) |
+| `data.endDate` | `string` | End of the billing period (`YYYY-MM-DD`) |
+| `data.totalEligible` | `number` | Total contracts that passed eligibility |
+| `data.totalInserted` | `number` | Total installments successfully created |
+| `data.created` | `array` | List of generated installment records |
+| `data.created[].installmentID` | `number` | ID of the created `supplier_installment` row |
+| `data.created[].contractID` | `string` | Associated contract ID (`PurchaseOrderAssetContract`) |
+| `data.created[].purchaseOrderID` | `string` | Associated purchase order ID |
+| `data.created[].parentInvoiceID` | `string` | Source supplier invoice ID |
+| `data.created[].parentInvoiceNumber` | `string` | Source supplier invoice number |
+| `data.created[].amount` | `number` | Installment amount (IDR) |
+| `data.created[].installDate` | `string` | Date the installment is issued |
+| `data.created[].dueDate` | `string` | Payment due date (`installDate + 7 days`) |