Add VIP fee discount tier logic

src/services/ledgerService.ts

@@ -1,5 +1,6 @@
 import { Pool, PoolClient } from 'pg';
 import { pool } from '../config/database';
+import { SupportedCurrency, currencyService, BASE_CURRENCY } from './currency';
 
 /**
  * Double-Entry Ledger Service
@@ -152,10 +153,12 @@
     description: string,
     entries: LedgerEntry[],
     transactionId?: string,
-    postedBy?: string
+    postedBy?: string,
+    currency?: SupportedCurrency,
+    conversionRate?: number
   ): Promise<PostedEntry[]> {
     const client = await this.pool.connect();
-    
+
     try {
       await client.query('BEGIN');
 
@@ -174,6 +177,18 @@
         );
       }
 
+      // Attach currency metadata if provided
+      const enrichedEntries = (currency && conversionRate)
+        ? entries.map(e => ({
+            ...e,
+            metadata: {
+              ...(e.metadata || {}),
+              currency,
+              conversionRate,
+            },
+          }))
+        : entries;
+
       // Call the database function to post atomically
       const result = await client.query(
         `SELECT * FROM post_transaction($1, $2, $3, $4, $5)`,
@@ -182,7 +197,7 @@
           description,
           transactionId || null,
           postedBy || null,
-          JSON.stringify(entries)
+          JSON.stringify(enrichedEntries)
         ]
       );
 
@@ -201,15 +216,18 @@
       client.release();
     }
   }
+/* Duplicate block removed */
 
   /**
-   * Post a deposit transaction
-   * Debit: Mobile Money Float (asset increases)
-   * Credit: Customer Balances (liability increases)
+   * Post a deposit transaction with currency conversion.
+   * `amount` and `fee` are in the original `currency`.
+   * The amounts are converted to base currency (USD) for ledger accounting.
+   * Metadata records original currency and conversion rate.
    */
-  async postDeposit(
+  async postDepositWithCurrency(
     amount: number,
     fee: number,
+    currency: SupportedCurrency,
     referenceNumber: string,
     transactionId: string,
     userId: string
@@ -228,8 +246,13 @@
     const entries: LedgerEntry[] = [
       {
         account_code: '1100', // Mobile Money Float
-        debit_amount: amount,
-        description: 'Customer deposit received'
+        debit_amount: amountConversion.convertedAmount,
+        description: 'Customer deposit received',
+        metadata: {
+          originalAmount: amount,
+          originalCurrency: currency,
+          conversionRate: amountConversion.rate,
+        },
       },
       {
         account_code: '2000', // Customer Balances
@@ -243,17 +266,24 @@
     if (fee > 0) {
       entries.push({
         account_code: '4100', // Deposit Fee Revenue
-        credit_amount: fee,
-        description: 'Deposit fee earned'
+        credit_amount: feeConversion.convertedAmount,
+        description: 'Deposit fee earned',
+        metadata: {
+          originalAmount: fee,
+          originalCurrency: currency,
+          conversionRate: feeConversion.rate,
+        },
       });
     }
 
     return this.postTransaction(
       referenceNumber,
-      `Deposit: ${amount} (fee: ${fee})`,
+      `Deposit: ${amount} ${currency} (fee: ${fee} ${currency})`,
       entries,
       transactionId,
-      userId
+      userId,
+      currency,
+      amountConversion.rate
     );
   }