Disallow downgrades in package shop

resources/js/admin/mobile/lib/packageShop.ts

@@ -1,23 +1,76 @@
 import type { Package } from '../../api';
 
-export function classifyPackageTier(price: number, activePrice: number | null): {
+type PackageChange = {
   isUpgrade: boolean;
   isDowngrade: boolean;
-} {
-  if (activePrice === null) {
+};
+
+function collectFeatures(pkg: Package | null): Set<string> {
+  if (!pkg?.features) {
+    return new Set();
+  }
+
+  return new Set(Object.entries(pkg.features).filter(([, enabled]) => enabled).map(([key]) => key));
+}
+
+function compareLimit(candidate: number | null, active: number | null): number {
+  if (active === null) {
+    return candidate === null ? 0 : -1;
+  }
+
+  if (candidate === null) {
+    return 1;
+  }
+
+  if (candidate > active) return 1;
+  if (candidate < active) return -1;
+  return 0;
+}
+
+export function classifyPackageChange(pkg: Package, active: Package | null): PackageChange {
+  if (!active) {
     return { isUpgrade: false, isDowngrade: false };
   }
 
-  return {
-    isUpgrade: price > activePrice,
-    isDowngrade: price < activePrice,
-  };
+  const activeFeatures = collectFeatures(active);
+  const candidateFeatures = collectFeatures(pkg);
+
+  const hasFeatureUpgrade = Array.from(candidateFeatures).some((feature) => !activeFeatures.has(feature));
+  const hasFeatureDowngrade = Array.from(activeFeatures).some((feature) => !candidateFeatures.has(feature));
+
+  const limitKeys: Array<keyof Package> = ['max_photos', 'max_guests', 'gallery_days'];
+  let hasLimitUpgrade = false;
+  let hasLimitDowngrade = false;
+
+  limitKeys.forEach((key) => {
+    const candidateLimit = pkg[key] ?? null;
+    const activeLimit = active[key] ?? null;
+    const delta = compareLimit(candidateLimit, activeLimit);
+    if (delta > 0) {
+      hasLimitUpgrade = true;
+    } else if (delta < 0) {
+      hasLimitDowngrade = true;
+    }
+  });
+
+  const hasUpgrade = hasFeatureUpgrade || hasLimitUpgrade;
+  const hasDowngrade = hasFeatureDowngrade || hasLimitDowngrade;
+
+  if (hasUpgrade) {
+    return { isUpgrade: true, isDowngrade: false };
+  }
+
+  if (hasDowngrade) {
+    return { isUpgrade: false, isDowngrade: true };
+  }
+
+  return { isUpgrade: false, isDowngrade: false };
 }
 
 export function selectRecommendedPackageId(
   packages: Package[],
   feature: string | null,
-  activePrice: number | null
+  activePackage: Package | null
 ): number | null {
   if (!feature) {
     return null;
@@ -28,12 +81,8 @@ export function selectRecommendedPackageId(
     return null;
   }
 
-  const upgradeCandidates =
-    activePrice === null
-      ? candidates
-      : candidates.filter((pkg) => pkg.price > activePrice);
-
-  const pool = upgradeCandidates.length ? upgradeCandidates : candidates;
+  const upgrades = candidates.filter((pkg) => classifyPackageChange(pkg, activePackage).isUpgrade);
+  const pool = upgrades.length ? upgrades : candidates;
   const sorted = [...pool].sort((a, b) => a.price - b.price);
 
   return sorted[0]?.id ?? null;