feat: created the getCurrentExpense route

backend/package.json

@@ -32,6 +32,7 @@
     "fastify-plugin": "^4.5.1",
     "otp-generator": "^4.0.1",
     "postgres": "^3.4.4",
-    "twilio": "^3.56.0"
+    "twilio": "^3.56.0",
+    "viem": "^2.9.21"
   }
 }

backend/src/routes/getCurrentExpense.ts

@@ -0,0 +1,49 @@
+import { sql } from 'drizzle-orm';
+import { and, between, eq, gte } from 'drizzle-orm/pg-core/expressions';
+import type { FastifyInstance } from 'fastify';
+import { formatUnits, parseUnits } from 'viem';
+
+import { usdcBalance, usdcTransfer } from '@/db/schema';
+import { addressRegex } from '.';
+
+export function getCurrentExpenseRoute(fastify: FastifyInstance) {
+  fastify.get('/get_current_expense', async (request, reply) => {
+    const { address } = request.query as { address?: string };
+    const decimal = 6;
+
+    if (!address) {
+      return reply.status(400).send({ error: 'Address is required.' });
+    }
+    // Validate address format
+    if (!addressRegex.test(address)) {
+      return reply.status(400).send({ error: 'Invalid address format.' });
+    }
+
+    try {
+      const currentDate = new Date();
+      // Calculate the date 7 days ago
+      const sevenDaysAgo = new Date(currentDate);
+      sevenDaysAgo.setDate(currentDate.getDate() - 7);
+      // Use Drizzle ORM to find expense by address
+      const expenses = await fastify.db
+        .select()
+        .from(usdcTransfer)
+        .where(
+          and(eq(usdcTransfer.fromAddress, address), gte(usdcTransfer.createdAt, sevenDaysAgo)),
+        );
+
+      // Calculate the sum of amounts
+      const totalAmount = expenses.reduce(
+        (acc, curr) => acc + parseUnits(curr.amount || '0', decimal),
+        parseUnits('0', decimal),
+      );
+
+      return reply.send({
+        cumulated_expense: formatUnits(totalAmount, decimal),
+      });
+    } catch (error) {
+      console.error(error);
+      return reply.status(500).send({ error: 'Internal server error' });
+    }
+  });
+}

backend/src/routes/index.ts

@@ -3,6 +3,7 @@ import { sql } from 'drizzle-orm';
 import type { FastifyInstance, FastifyReply, FastifyRequest } from 'fastify';
 
 import { getBalanceRoute } from './getBalance';
+import { getCurrentExpenseRoute } from './getCurrentExpense';
 import { getHistoricalBalanceRoute } from './getHistoricalBalance';
 import { getOtp } from './getOtp';
 import { getTransactionHistory } from './getTransactionHistory';
@@ -14,6 +15,7 @@ export const addressRegex = /^0x0[0-9a-fA-F]{63}$/;
 export function declareRoutes(fastify: FastifyInstance) {
   getStatusRoute(fastify);
   getBalanceRoute(fastify);
+  getCurrentExpenseRoute(fastify);
   getTransactionHistory(fastify);
   getRegisterRoute(fastify);
   getOtp(fastify);