From ef46cdbe2968a80db81f76b1602beb967792f262 Mon Sep 17 00:00:00 2001
From: dmitriylaukhin <laukhin@dementiy.com>
Date: Mon, 6 Jul 2026 12:00:07 +0500
Subject: [PATCH] Add paid-access and usage limit helpers for clean-pdf

---
 src/lib/clean-pdf/__tests__/access.test.ts | 43 ++++++++++++++++
 src/lib/clean-pdf/access.ts                | 60 ++++++++++++++++++++++
 2 files changed, 103 insertions(+)
 create mode 100644 src/lib/clean-pdf/__tests__/access.test.ts
 create mode 100644 src/lib/clean-pdf/access.ts

diff --git a/src/lib/clean-pdf/__tests__/access.test.ts b/src/lib/clean-pdf/__tests__/access.test.ts
new file mode 100644
index 0000000..1910569
--- /dev/null
+++ b/src/lib/clean-pdf/__tests__/access.test.ts
@@ -0,0 +1,43 @@
+import { describe, expect, it } from "vitest";
+import { decidePaidAccess, monthStartUtc } from "@/lib/clean-pdf/access";
+
+const now = new Date("2026-07-06T10:00:00Z");
+const freeSlug = "obsidian-start";
+
+describe("decidePaidAccess", () => {
+  it("платный enrollment без срока — да", () => {
+    expect(decidePaidAccess({ role: "student", banned: false, freeSlug, now,
+      enrollments: [{ courseSlug: "zotero", expiresAt: null }] })).toBe(true);
+  });
+
+  it("только бесплатный курс — нет", () => {
+    expect(decidePaidAccess({ role: "student", banned: false, freeSlug, now,
+      enrollments: [{ courseSlug: "obsidian-start", expiresAt: null }] })).toBe(false);
+  });
+
+  it("без enrollments — нет", () => {
+    expect(decidePaidAccess({ role: "student", banned: false, freeSlug, now, enrollments: [] })).toBe(false);
+  });
+
+  it("истёкший платный — нет, живой срок — да", () => {
+    expect(decidePaidAccess({ role: "student", banned: false, freeSlug, now,
+      enrollments: [{ courseSlug: "zotero", expiresAt: new Date("2026-01-01") }] })).toBe(false);
+    expect(decidePaidAccess({ role: "student", banned: false, freeSlug, now,
+      enrollments: [{ courseSlug: "zotero", expiresAt: new Date("2027-01-01") }] })).toBe(true);
+  });
+
+  it("admin и curator — да даже без курсов", () => {
+    expect(decidePaidAccess({ role: "admin", banned: false, freeSlug, now, enrollments: [] })).toBe(true);
+    expect(decidePaidAccess({ role: "curator", banned: false, freeSlug, now, enrollments: [] })).toBe(true);
+  });
+
+  it("бан всё перекрывает", () => {
+    expect(decidePaidAccess({ role: "admin", banned: true, freeSlug, now, enrollments: [] })).toBe(false);
+  });
+});
+
+describe("monthStartUtc", () => {
+  it("возвращает первое число месяца 00:00 UTC", () => {
+    expect(monthStartUtc(new Date("2026-07-06T23:59:59Z")).toISOString()).toBe("2026-07-01T00:00:00.000Z");
+  });
+});
diff --git a/src/lib/clean-pdf/access.ts b/src/lib/clean-pdf/access.ts
new file mode 100644
index 0000000..a56b3eb
--- /dev/null
+++ b/src/lib/clean-pdf/access.ts
@@ -0,0 +1,60 @@
+import { prisma } from "@/lib/prisma";
+
+// НЕ "clean-pdf": так CopyButton логирует копирования — они не должны тратить лимит
+export const PDF_TOOL_ID = "clean-pdf-generate";
+export const BURST_LIMIT = 5; // успешных генераций в минуту
+const BURST_WINDOW_MS = 60_000;
+
+export function decidePaidAccess(input: {
+  role: string;
+  banned: boolean;
+  enrollments: { courseSlug: string; expiresAt: Date | null }[];
+  freeSlug: string;
+  now?: Date;
+}): boolean {
+  const now = input.now ?? new Date();
+  if (input.banned) return false;
+  if (input.role === "admin" || input.role === "curator") return true;
+  return input.enrollments.some(
+    (e) => e.courseSlug !== input.freeSlug && (e.expiresAt === null || e.expiresAt > now),
+  );
+}
+
+export async function hasPaidAccess(userId: string): Promise<boolean> {
+  const user = await prisma.user.findUnique({
+    where: { id: userId },
+    select: {
+      role: true,
+      banned: true,
+      enrollments: { select: { expiresAt: true, course: { select: { slug: true } } } },
+    },
+  });
+  if (!user) return false;
+  return decidePaidAccess({
+    role: user.role,
+    banned: user.banned ?? false,
+    freeSlug: process.env.FREE_COURSE_SLUG ?? "obsidian-start",
+    enrollments: user.enrollments.map((e) => ({ courseSlug: e.course.slug, expiresAt: e.expiresAt })),
+  });
+}
+
+export function monthStartUtc(now: Date): Date {
+  return new Date(Date.UTC(now.getUTCFullYear(), now.getUTCMonth(), 1));
+}
+
+export function getMonthlyLimit(): number {
+  const n = Number(process.env.PDF_MONTHLY_LIMIT);
+  return Number.isFinite(n) && n > 0 ? n : 100;
+}
+
+export async function getMonthlyUsage(userId: string): Promise<number> {
+  return prisma.toolUsage.count({
+    where: { userId, tool: PDF_TOOL_ID, createdAt: { gte: monthStartUtc(new Date()) } },
+  });
+}
+
+export async function getBurstUsage(userId: string): Promise<number> {
+  return prisma.toolUsage.count({
+    where: { userId, tool: PDF_TOOL_ID, createdAt: { gte: new Date(Date.now() - BURST_WINDOW_MS) } },
+  });
+}