feat: add update price modifier for existing customers based on last license date

shop/lib/license-transform.ts

@@ -86,7 +86,8 @@ export function buildOrderSnapshot(
   products: Product[],
   categories: Category[],
   billingInterval?: 'one_time' | 'monthly',
-  moduleQuantities?: Record<string, number>
+  moduleQuantities?: Record<string, number>,
+  lastLicenseDate?: string | null
 ): OrderSnapshot {
   const items: OrderItem[] = []
   let subtotal = 0
@@ -131,14 +132,43 @@ export function buildOrderSnapshot(
     })
   }
 
-  const taxAmount = Math.round(subtotal * (dominantTaxRate / 100) * 100) / 100
-  const total = Math.round((subtotal + taxAmount) * 100) / 100
-
   // Wenn billingInterval übergeben, dieses nutzen; sonst automatisch ermitteln
   const billingCycle = billingInterval || (items.every((i) => i.billing_interval === 'one_time')
     ? 'one_time'
     : 'monthly')
 
+  let multiplier = 1
+  if (lastLicenseDate && billingCycle === 'one_time') {
+    const lastDate = new Date(lastLicenseDate)
+    const today = new Date()
+    const yearsDiff = today.getFullYear() - lastDate.getFullYear()
+    const monthsDiff = today.getMonth() - lastDate.getMonth()
+    const months = yearsDiff * 12 + monthsDiff
+
+    if (months <= 12) {
+      multiplier = 0
+    } else if (months <= 14) {
+      multiplier = 0.15
+    } else if (months <= 25) {
+      multiplier = 0.30
+    } else if (months <= 37) {
+      multiplier = 0.45
+    } else if (months <= 49) {
+      multiplier = 0.60
+    } else {
+      multiplier = 0.90
+    }
+
+    // Multiply item_total in items by multiplier
+    items.forEach(item => {
+      item.item_total = item.item_total * multiplier
+    })
+    subtotal = subtotal * multiplier
+  }
+
+  const taxAmount = Math.round(subtotal * (dominantTaxRate / 100) * 100) / 100
+  const total = Math.round((subtotal + taxAmount) * 100) / 100
+
   return {
     schema_version: 1,
     billing_cycle: billingCycle,
@@ -147,6 +177,8 @@ export function buildOrderSnapshot(
     tax_rate: dominantTaxRate,
     tax_amount: taxAmount,
     total,
+    last_license_date: lastLicenseDate || null,
+    price_multiplier: lastLicenseDate && billingCycle === 'one_time' ? multiplier : null,
   }
 }