1603/endpoint to check if user email exists

server/src/subscriber/subscriber.controller.ts

@@ -169,4 +169,46 @@ export class SubscriberController {
     });
     return;
   }
+
+  @Get("/subscribers/email/:email")
+  async getEmail(@Param() params, @Res() response) {
+    if (!validateEmail(params.email)) {
+      response.status(400).send({
+        error: "Invalid email address."
+      })
+      return;
+    }
+
+    const existingUser = await this.subscriberService.findByEmail(params.email);
+    if (existingUser.code === 404) {
+      response.status(404).send({
+        error: "User not found."
+      })
+      return;
+    }
+
+    const userExistsInCurrentList = existingUser['1'].result[params.email].contact.list_ids.includes(this.list);
+    const existingUserListConfirmed = existingUser['1'].result[params.email].contact.custom_fields[`zap_${this.sendgridEnvironment}_confirmed`];
+
+    if (userExistsInCurrentList && existingUserListConfirmed) {
+      response.status(201).send({
+        confirmed: true,
+        message: "User already subscribed."
+      })
+      return;
+    }
+
+    if (existingUserListConfirmed === 0) {
+      response.status(201).send({
+        confirmed: false,
+        message: "User is subscribed but must confirm."
+      })
+      return;
+    }
+
+    response.status(404).send({
+      error: "Not found."
+    })
+    return;
+  }
 }