From bd59a3dbd85b77261fe79a159e28a6890d1e614e Mon Sep 17 00:00:00 2001
From: trevor-anderson <43518091+trevor-anderson@users.noreply.github.com>
Date: Sat, 22 Jun 2024 14:21:36 -0400
Subject: [PATCH] feat: add auth method
 verifyUserIsAuthorizedToAccessPaidContent

---
 ...serIsAuthorizedToAccessPaidContent.test.ts | 61 +++++++++++++
 ...rifyUserIsAuthorizedToAccessPaidContent.ts | 87 +++++++++++++++++++
 2 files changed, 148 insertions(+)
 create mode 100644 src/services/AuthService/verifyUserIsAuthorizedToAccessPaidContent.test.ts
 create mode 100644 src/services/AuthService/verifyUserIsAuthorizedToAccessPaidContent.ts

diff --git a/src/services/AuthService/verifyUserIsAuthorizedToAccessPaidContent.test.ts b/src/services/AuthService/verifyUserIsAuthorizedToAccessPaidContent.test.ts
new file mode 100644
index 0000000..7a8c053
--- /dev/null
+++ b/src/services/AuthService/verifyUserIsAuthorizedToAccessPaidContent.test.ts
@@ -0,0 +1,61 @@
+import { MOCK_USERS, MOCK_USER_SCAs } from "@/tests/staticMockItems";
+import { verifyUserIsAuthorizedToAccessPaidContent } from "./verifyUserIsAuthorizedToAccessPaidContent.js";
+import type { UserSubscription } from "@/types/graphql.js";
+import type { AuthTokenPayload } from "@/types/open-api.js";
+
+describe("verifyUserIsAuthorizedToAccessPaidContent()", () => {
+  const YEAR_2000 = new Date(2000, 0);
+  const YEAR_9999 = new Date(9999, 0);
+
+  const mockUserWithSubFields = (
+    subFieldsToTest: Pick<UserSubscription, "status" | "currentPeriodEnd">
+  ): AuthTokenPayload => ({
+    ...MOCK_USERS.USER_A,
+    stripeConnectAccount: MOCK_USER_SCAs.SCA_A,
+    subscription: { id: "", ...subFieldsToTest },
+  });
+
+  test(`does not throw when called with a valid "active" subscription`, () => {
+    expect(() => {
+      verifyUserIsAuthorizedToAccessPaidContent({
+        authenticatedUser: mockUserWithSubFields({
+          status: "active",
+          currentPeriodEnd: YEAR_9999,
+        }),
+      });
+    }).not.toThrow();
+  });
+
+  test(`does not throw when called with a valid "trialing" subscription`, () => {
+    expect(() => {
+      verifyUserIsAuthorizedToAccessPaidContent({
+        authenticatedUser: mockUserWithSubFields({
+          status: "trialing",
+          currentPeriodEnd: YEAR_9999,
+        }),
+      });
+    }).not.toThrow();
+  });
+
+  test(`throws an error when called with a subscription with an invalid status`, () => {
+    expect(() => {
+      verifyUserIsAuthorizedToAccessPaidContent({
+        authenticatedUser: mockUserWithSubFields({
+          status: "past_due",
+          currentPeriodEnd: YEAR_9999,
+        }),
+      });
+    }).toThrow("past due");
+  });
+
+  test(`throws an error when called with an expired subscription`, () => {
+    expect(() => {
+      verifyUserIsAuthorizedToAccessPaidContent({
+        authenticatedUser: mockUserWithSubFields({
+          status: "active",
+          currentPeriodEnd: YEAR_2000,
+        }),
+      });
+    }).toThrow("expired");
+  });
+});
diff --git a/src/services/AuthService/verifyUserIsAuthorizedToAccessPaidContent.ts b/src/services/AuthService/verifyUserIsAuthorizedToAccessPaidContent.ts
new file mode 100644
index 0000000..99ef974
--- /dev/null
+++ b/src/services/AuthService/verifyUserIsAuthorizedToAccessPaidContent.ts
@@ -0,0 +1,87 @@
+import { hasKey } from "@nerdware/ts-type-safety-utils";
+import dayjs from "dayjs";
+import { PaymentRequiredError } from "@/utils/httpErrors.js";
+import type { SubscriptionStatus } from "@/types/graphql.js";
+import type { AuthTokenPayload } from "@/types/open-api.js";
+
+/**
+ * ### AuthService: Verify User Is Authorized To Access Paid Content
+ *
+ * Verify whether a User's existing subscription is valid for service-access.
+ *
+ * A UserSubscription is only considered valid for service-access if all of the following are true:
+ *
+ *    1. The subscription's status is `active` or `trialing`.
+ *    2. The subscription's `currentPeriodEnd` timestamp is in the future.
+ */
+export const verifyUserIsAuthorizedToAccessPaidContent = ({
+  authenticatedUser,
+}: {
+  authenticatedUser: AuthTokenPayload;
+}) => {
+  // Destructure necessary fields
+  const { status, currentPeriodEnd } = authenticatedUser.subscription ?? {};
+
+  if (
+    !status ||
+    !hasKey(SUB_STATUS_AUTH_METADATA, status) ||
+    SUB_STATUS_AUTH_METADATA[status]?.isValid !== true ||
+    !currentPeriodEnd ||
+    !dayjs(currentPeriodEnd).isValid()
+  ) {
+    throw new Error(
+      !!status && hasKey(SUB_STATUS_AUTH_METADATA, status)
+        ? SUB_STATUS_AUTH_METADATA[status]?.reason ?? "Invalid subscription."
+        : "Invalid subscription."
+    );
+  }
+
+  // Coerce to unix timestamp in seconds and compare
+  if (dayjs().unix() >= dayjs(currentPeriodEnd).unix()) {
+    throw new PaymentRequiredError(
+      "This subscription has expired — please update your payment settings to re-activate your subscription."
+    );
+  }
+};
+
+/**
+ * Subscription-Status authorization metadata objects:
+ *
+ * - Subscription statuses which indicate a sub IS VALID for Fixit service usage
+ *   contain `isValid: true`.
+ * - Subscription statuses which indicate a sub IS NOT VALID for Fixit service
+ *   usage contain a `reason` plainly explaining to end users _why_ their sub is
+ *   invalid, and what their course of action should be to resolve the issue.
+ *
+ * @see https://stripe.com/docs/api/subscriptions/object#subscription_object-status
+ */
+export const SUB_STATUS_AUTH_METADATA: Readonly<
+  Record<
+    SubscriptionStatus,
+    { isValid: true; reason?: never } | { isValid?: false; reason: string }
+  >
+> = {
+  // Statuses which indicate a subscription IS VALID for service usage:
+  active: {
+    isValid: true,
+  },
+  trialing: {
+    isValid: true,
+  },
+  // Statuses which indicate a subscription IS NOT VALID for service usage:
+  incomplete: {
+    reason: "Sorry, your subscription payment is incomplete.",
+  },
+  incomplete_expired: {
+    reason: "Sorry, please try again.",
+  },
+  past_due: {
+    reason: "Sorry, payment for your subscription is past due. Please submit payment and try again.", // prettier-ignore
+  },
+  canceled: {
+    reason: "Sorry, this subscription was canceled.",
+  },
+  unpaid: {
+    reason: "Sorry, payment for your subscription is past due. Please submit payment and try again.", // prettier-ignore
+  },
+};