From 9e25aa1f9f329b2e293bc7879e32f7fb7003549a Mon Sep 17 00:00:00 2001
From: ankitsridhar16 <ankit.sridhar16@gmail.com>
Date: Thu, 19 Jan 2023 01:34:11 +0530
Subject: [PATCH] feat: introducing new subscription handler interface and user
 defined/primitive types

---
 .../src/subscription-handler.ts               | 49 +++++++++++++++++++
 .../src/types/module-types.ts                 |  4 ++
 .../src/types/primitive-types.ts              |  1 +
 3 files changed, 54 insertions(+)
 create mode 100644 packages/hoppscotch-backend/src/subscription-handler.ts
 create mode 100644 packages/hoppscotch-backend/src/types/module-types.ts
 create mode 100644 packages/hoppscotch-backend/src/types/primitive-types.ts

diff --git a/packages/hoppscotch-backend/src/subscription-handler.ts b/packages/hoppscotch-backend/src/subscription-handler.ts
new file mode 100644
index 000000000..f07e62c89
--- /dev/null
+++ b/packages/hoppscotch-backend/src/subscription-handler.ts
@@ -0,0 +1,49 @@
+import { Injectable } from '@nestjs/common';
+import { PubSubService } from './pubsub/pubsub.service';
+import { PrimitiveTypes } from './types/primitive-types';
+import { ModuleTypes } from './types/module-types';
+
+// Custom generic type to indicate the type of module
+type ModuleType = PrimitiveTypes | ModuleTypes;
+
+// Contains constants for the subscription types we send to pubsub service
+enum SubscriptionType {
+  Created = 'created',
+  Updated = 'updated',
+  Deleted = 'deleted',
+  DeleteMany = 'delete_many',
+}
+
+@Injectable()
+export class SubscriptionHandler {
+  constructor(private readonly pubsub: PubSubService) {}
+
+  /**
+   * Publishes a subscription using the pubsub module
+   * @param topic a string containing the module name, a uid and the type of subscription
+   * @param moduleType type of the module model being called
+   * @returns a promise of type void
+   */
+  async publish(
+    topic: string,
+    subscriptionType: SubscriptionType,
+    moduleType: ModuleType,
+  ) {
+    switch (subscriptionType) {
+      case SubscriptionType.Created:
+        await this.pubsub.publish(`${topic}/created`, moduleType);
+        break;
+      case SubscriptionType.Updated:
+        await this.pubsub.publish(`${topic}/updated`, moduleType);
+        break;
+      case SubscriptionType.Deleted:
+        await this.pubsub.publish(`${topic}/deleted`, moduleType);
+        break;
+      case SubscriptionType.DeleteMany:
+        await this.pubsub.publish(`${topic}/delete_many`, moduleType);
+        break;
+      default:
+        break;
+    }
+  }
+}
diff --git a/packages/hoppscotch-backend/src/types/module-types.ts b/packages/hoppscotch-backend/src/types/module-types.ts
new file mode 100644
index 000000000..356fcc816
--- /dev/null
+++ b/packages/hoppscotch-backend/src/types/module-types.ts
@@ -0,0 +1,4 @@
+import { UserEnvironment } from '../user-environment/user-environments.model';
+import { User } from '../user/user.model';
+
+export type ModuleTypes = UserEnvironment | User;
diff --git a/packages/hoppscotch-backend/src/types/primitive-types.ts b/packages/hoppscotch-backend/src/types/primitive-types.ts
new file mode 100644
index 000000000..11918cf33
--- /dev/null
+++ b/packages/hoppscotch-backend/src/types/primitive-types.ts
@@ -0,0 +1 @@
+export type PrimitiveTypes = number | string | boolean;