add update notification campaign

src/function/sync/get-server-data-status/campaign.ts

@@ -0,0 +1,64 @@
+/*
+ * server component for the TimeLimit App
+ * Copyright (C) 2019 - 2026 Jonas Lochmann
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import { createHash } from 'crypto'
+
+const updateMessage =
+  'Please update the TimeLimit App to the latest release. ' +
+  'In your current version, synchronization and purchases may not work as expected.' +
+  '\n\n' +
+  'Bitte die TimeLimit-App aktualisieren. ' +
+  'Mit der momentan installierten Version kann es zu Einschränkungen bei der Synchronisation und bei Käufen kommen.'
+
+export function getCampaign({ familyId, isClient750OrNewer }: {
+  familyId: string
+  isClient750OrNewer: boolean
+}): string | undefined {
+  const now = Date.now()
+
+  const campaigns = [
+    {
+      enable: !isClient750OrNewer,
+      seed: 'Q05NwM4nyUfiYg6K', // require('crypto').randomBytes(12).toString('base64')
+      startTime: 1784160000000, // new Date('2026-07-16').valueOf()
+      endTime: 1785369600000, // new Date('2026-07-30').valueOf()
+      startPercentage: 0,
+      endPercentage: 10,
+      message: updateMessage,
+    }
+  ]
+
+  for (const campaign of campaigns) {
+    if (!campaign.enable) continue
+    if (now < campaign.startTime) continue
+
+    const progress = Math.min((now - campaign.startTime) / (campaign.endTime - campaign.startTime), 1)
+    const chanceInPercent = campaign.startPercentage + progress * (campaign.endPercentage - campaign.startPercentage)
+
+    const hasher = createHash('SHA3-224')
+
+    hasher.update(campaign.seed, 'base64')
+    hasher.update(familyId)
+
+    const hash = hasher.digest().readUInt32BE(0)
+    const match = hash < chanceInPercent * Math.pow(2, 32) / 100
+
+    if (match) return campaign.message
+  }
+
+  return undefined
+}