From 37a5464b1f98449ef27f36f8200232bb47669367 Mon Sep 17 00:00:00 2001
From: Sam Huynh <samhwang2112.dev@gmail.com>
Date: Thu, 7 Mar 2024 16:50:06 +1100
Subject: [PATCH] feat: block user from adding referral code if they have added
 for that service already

---
 src/commands/referral/referralNew.test.ts | 32 +++++++++++++++++++++++
 src/commands/referral/referralNew.ts      | 13 +++++++++
 2 files changed, 45 insertions(+)

diff --git a/src/commands/referral/referralNew.test.ts b/src/commands/referral/referralNew.test.ts
index 9d0139c1..cd312bf2 100644
--- a/src/commands/referral/referralNew.test.ts
+++ b/src/commands/referral/referralNew.test.ts
@@ -120,6 +120,38 @@ describe('execute', () => {
     expect(mockChatInputInteraction.reply).toBeCalledWith('expiry_date has already expired');
   });
 
+  it('should block adding referral code if the user already has one', async () => {
+    const data = {
+      service: services[0],
+      code: 'SomeCodeHere',
+      expiry_date: `04/04/${new Date().getFullYear() + 1}`,
+      userId: '1234',
+    };
+
+    const mockPrismaClient = mockDeep<PrismaClient>();
+    mockPrismaClient.referralCode.findFirst.mockResolvedValueOnce({
+      id: '12345',
+      service: data.service,
+      code: data.code,
+      expiry_date: new Date(data.expiry_date),
+      userId: data.userId,
+    });
+    mockGetDbClient.mockReturnValueOnce(mockPrismaClient);
+
+    mockChatInputInteraction.user.id = data.userId;
+    mockChatInputInteraction.options.getString.mockImplementation((name: string, required?: boolean) => {
+      if (name === 'service') return data.service;
+      if (name === 'link_or_code') return data.code;
+      if (name === 'expiry_date') return data.expiry_date;
+
+      return null;
+    });
+
+    await execute(mockChatInputInteraction);
+
+    expect(mockChatInputInteraction.reply).toBeCalledWith(`You have already entered the referral code for ${services[0]}.`);
+  });
+
   it('should create a new referral code', async () => {
     const data = {
       service: services[0],
diff --git a/src/commands/referral/referralNew.ts b/src/commands/referral/referralNew.ts
index 1383446c..d1ad7686 100644
--- a/src/commands/referral/referralNew.ts
+++ b/src/commands/referral/referralNew.ts
@@ -67,6 +67,19 @@ export const execute: CommandHandler = async (interaction) => {
   const userId = interaction.user.id;
   const nickname = interaction.user.displayName;
 
+  const existingReferralCode = await db.referralCode.findFirst({
+    where: {
+      service,
+      userId,
+    },
+  });
+
+  if (existingReferralCode) {
+    logger.error(`[referral-new]: Referral code for ${service} by ${nickname} already exists.`);
+    await interaction.reply(`You have already entered the referral code for ${service}.`);
+    return;
+  }
+
   try {
     const newReferralCode = await db.referralCode.create({
       data: {