add full version debts system

foundation for granting the full version while consuming the same amount
automatically at the next purchase

src/function/parent/create-family.ts

@@ -1,6 +1,6 @@
 /*
  * server component for the TimeLimit App
- * Copyright (C) 2019 - 2022 Jonas Lochmann
+ * 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
@@ -82,7 +82,8 @@ export async function createFamily ({
       fullVersionUntil: (Date.now() + 1000 * 60 * 60 * 24 * 14).toString(10),
       hasFullVersion: true,
       nextServerKeyRequestSeq: '1',
-      u2fKeysVersion: generateVersionId()
+      u2fKeysVersion: generateVersionId(),
+      fullVersionDebts: '0'
     }, { transaction })
 
     // create parent user

src/function/purchase/add-purchase.ts

@@ -1,6 +1,6 @@
 /*
  * server component for the TimeLimit App
- * Copyright (C) 2019 - 2022 Jonas Lochmann
+ * 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
@@ -57,11 +57,19 @@ export const addPurchase = async ({ database, familyId, type, service, transacti
   }
 
   const previousFullVersionEndTime = familyEntry.fullVersionUntil
+  const previousFullVersionDebts = parseInt(familyEntry.fullVersionDebts, 10)
 
-  const newFullVersionUntil = Math.max(parseInt(familyEntry.fullVersionUntil, 10), Date.now()) + (type === 'year' ? year : month)
+  const typeDuration = type === 'year' ? year : month
 
-  familyEntry.fullVersionUntil = newFullVersionUntil.toString(10)
-  familyEntry.hasFullVersion = true
+  if (typeDuration > previousFullVersionDebts) {
+    const newFullVersionUntil = Math.max(parseInt(familyEntry.fullVersionUntil, 10), Date.now()) + typeDuration - previousFullVersionDebts
+
+    familyEntry.fullVersionUntil = newFullVersionUntil.toString(10)
+    familyEntry.fullVersionDebts = '0'
+    familyEntry.hasFullVersion = true
+  } else {
+    familyEntry.fullVersionDebts = (previousFullVersionDebts - typeDuration).toString(10)
+  }
 
   await familyEntry.save({ transaction })
 
@@ -72,7 +80,7 @@ export const addPurchase = async ({ database, familyId, type, service, transacti
     type,
     loggedAt: Date.now().toString(10),
     previousFullVersionEndTime,
-    newFullVersionEndTime: newFullVersionUntil.toString(10)
+    newFullVersionEndTime: familyEntry.fullVersionUntil
   }, {
     transaction
   })

src/function/purchase/can-do-next-purchase.ts

@@ -1,6 +1,6 @@
 /*
  * server component for the TimeLimit App
- * Copyright (C) 2019 Jonas Lochmann
+ * 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
@@ -15,6 +15,9 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-export const canDoNextPurchase = ({ fullVersionUntil }: {fullVersionUntil: number}) => (
-  fullVersionUntil < (Date.now() + 1000 * 60 * 60 * 24 * 31)  // 31 days
+export const canDoNextPurchase = ({ fullVersionUntil, fullVersionDebts }: {
+  fullVersionUntil: number
+  fullVersionDebts: number
+}) => (
+  (fullVersionUntil - fullVersionDebts) < (Date.now() + 1000 * 60 * 60 * 24 * 31)  // 31 days
 )

src/function/purchase/require-family-entry.ts

@@ -1,6 +1,6 @@
 /*
  * server component for the TimeLimit App
- * Copyright (C) 2019 - 2020 Jonas Lochmann
+ * 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
@@ -43,7 +43,7 @@ export const requireFamilyEntry = async ({ database, deviceAuthToken, transactio
     where: {
       familyId: deviceEntry.familyId
     },
-    attributes: ['fullVersionUntil'],
+    attributes: ['fullVersionUntil', 'fullVersionDebts'],
     transaction
   })
 
@@ -52,7 +52,8 @@ export const requireFamilyEntry = async ({ database, deviceAuthToken, transactio
   }
 
   const familyEntry = {
-    fullVersionUntil: familyEntryUnsafe.fullVersionUntil
+    fullVersionUntil: familyEntryUnsafe.fullVersionUntil,
+    fullVersionDebts: familyEntryUnsafe.fullVersionDebts,
   }
 
   return familyEntry