feat(project): init

lib/quota.ts

@@ -0,0 +1,101 @@
+import "server-only";
+
+import { toPublicUser } from "@/lib/auth";
+import {
+  getSettingsSnapshot,
+  getUsageForUser,
+  listUserSummaries,
+} from "@/lib/db";
+import { getCurrentPeriodKey } from "@/lib/quota-core";
+import type { AdminSnapshot, QuotaSnapshot, UserRecord } from "@/lib/types";
+
+type QuotaUser = Pick<UserRecord, "id" | "role" | "monthlyQuota">;
+
+export function getQuotaSnapshotForUser(
+  user: QuotaUser | null | undefined,
+): QuotaSnapshot {
+  const periodKey = getCurrentPeriodKey();
+
+  if (!user || user.role === "admin") {
+    return {
+      periodKey,
+      limit: null,
+      used: user ? getUsageForUser(user.id, periodKey) : 0,
+      remaining: null,
+      isUnlimited: true,
+    };
+  }
+
+  const settings = getSettingsSnapshot();
+  const limit =
+    user.monthlyQuota === null
+      ? settings.defaultMonthlyQuota
+      : user.monthlyQuota;
+  const used = getUsageForUser(user.id, periodKey);
+
+  return {
+    periodKey,
+    limit,
+    used,
+    remaining: Math.max(limit - used, 0),
+    isUnlimited: false,
+  };
+}
+
+export function assertCanGenerate(user: QuotaUser): QuotaSnapshot {
+  const quotaSnapshot = getQuotaSnapshotForUser(user);
+  const remaining = quotaSnapshot.remaining ?? 0;
+
+  if (!quotaSnapshot.isUnlimited && remaining <= 0) {
+    const error = new Error(
+      "本月额度已用完，请联系管理员调整额度。",
+    ) as Error & {
+      statusCode?: number;
+    };
+    error.statusCode = 403;
+    throw error;
+  }
+
+  return quotaSnapshot;
+}
+
+export function buildAdminQuotaSummaries(): AdminSnapshot {
+  const settings = getSettingsSnapshot();
+  const periodKey = getCurrentPeriodKey();
+  const users = listUserSummaries(periodKey).map((user) => {
+    const publicUser = toPublicUser(user);
+
+    if (!publicUser) {
+      throw new Error("Failed to sanitize user record.");
+    }
+
+    if (user.role === "admin") {
+      return {
+        ...publicUser,
+        usedThisPeriod: user.usedThisPeriod,
+        limit: null,
+        remaining: null,
+        isUnlimited: true,
+      };
+    }
+
+    const limit =
+      user.monthlyQuota === null
+        ? settings.defaultMonthlyQuota
+        : user.monthlyQuota;
+
+    return {
+      ...publicUser,
+      usedThisPeriod: user.usedThisPeriod,
+      limit,
+      remaining: Math.max(limit - user.usedThisPeriod, 0),
+      isUnlimited: false,
+    };
+  });
+
+  return {
+    settings,
+    periodKey,
+    users,
+  };
+}