Fas 2 steg 3: Household Trust Score (admin + i18n status i appen)

packages/inventory-engine/src/trust.ts

@@ -19,6 +19,7 @@ export interface InventoryItemLike {
   lastVerifiedAt: Date | string | null;
   quantity: number;
   updatedAt: Date | string;
+  depletedAt?: Date | string | null;
 }
 
 export interface TrustResult {
@@ -118,6 +119,103 @@ export function itemTrustState(
   return computeTrust(item, now, profile).state;
 }
 
+export interface HouseholdTrustInput {
+  items: InventoryItemLike[];
+  /** Antal justeringstransaktioner senaste 30 dagarna (korrigeringsfrekvens). */
+  correctionCount30d: number;
+  /** Totalt antal transaktioner senaste 30 dagarna (används för korrigeringsfrekvens). */
+  transactionCount30d: number;
+}
+
+export interface HouseholdTrustResult {
+  score: number; // 0–100
+  status: "up_to_date" | "needs_check" | "uncertain";
+}
+
+export const TRUST_STATUS_THRESHOLDS = {
+  upToDate: 80,
+  needsCheck: 50,
+} as const;
+
+/**
+ * Deterministisk household trust score 0–100.
+ *
+ * Viktade komponenter (Fas 2 §5.3):
+ * - 25% verifierade poster (verifiedByUser)
+ * - 25% ålder på senaste kontroll (nyare = bättre)
+ * - 20% andel uppskattade mängder (lägre confidence ger mer osäkerhet)
+ * - 15% poster som borde vara slut (låg quantity utan depletedAt straffar)
+ * - 15% korrigeringsfrekvens (fler korrigeringar = lägre förtroende)
+ *
+ * Decay påverkar FORTROENDE, inte ätbarhet.
+ */
+export function householdTrustScore(
+  input: HouseholdTrustInput,
+  now: Date = new Date(),
+): HouseholdTrustResult {
+  const items = input.items.filter((i) => i.quantity > 0 && !i.depletedAt);
+  if (items.length === 0) {
+    return { score: 100, status: "up_to_date" };
+  }
+
+  const nowMs = now.getTime();
+
+  // 1. Andel verifierade (0–100)
+  const verifiedRatio = items.filter((i) => i.verifiedByUser).length / items.length;
+  const verifiedScore = verifiedRatio * 100;
+
+  // 2. Ålder på senaste kontroll (0–100, 100 = alla kontrollerade inom 7 dagar)
+  const ageScore =
+    items.reduce((sum, i) => {
+      const verifiedMs = i.lastVerifiedAt ? new Date(i.lastVerifiedAt).getTime() : null;
+      const referenceMs = verifiedMs ?? new Date(i.updatedAt).getTime();
+      const days = Math.max(0, (nowMs - referenceMs) / 86_400_000);
+      return sum + Math.max(0, 100 - (days / 30) * 100);
+    }, 0) / items.length;
+
+  // 3. Andel uppskattade mängder (0–100, 100 = alla har confidence 1)
+  const confidenceScore =
+    items.reduce((sum, i) => sum + Math.min(1, Math.max(0, i.confidence)), 0) / items.length * 100;
+
+  // 4. Poster som borde vara slut (0–100, 100 = inga låga kvantiteter)
+  const depletionScore =
+    items.reduce((sum, i) => {
+      const qty = i.quantity;
+      if (qty <= 0) return sum + 0;
+      if (qty < 0.2) return sum + 40;
+      if (qty < 0.5) return sum + 70;
+      return sum + 100;
+    }, 0) / items.length;
+
+  // 5. Korrigeringsfrekvens (0–100, 100 = inga korrigeringar)
+  const correctionRatio =
+    input.transactionCount30d > 0
+      ? input.correctionCount30d / input.transactionCount30d
+      : 0;
+  const correctionScore = Math.max(0, 100 - correctionRatio * 200);
+
+  const score = Math.round(
+    verifiedScore * 0.25 +
+      ageScore * 0.25 +
+      confidenceScore * 0.20 +
+      depletionScore * 0.15 +
+      correctionScore * 0.15,
+  );
+
+  const clamped = Math.max(0, Math.min(100, score));
+
+  let status: HouseholdTrustResult["status"];
+  if (clamped >= TRUST_STATUS_THRESHOLDS.upToDate) {
+    status = "up_to_date";
+  } else if (clamped >= TRUST_STATUS_THRESHOLDS.needsCheck) {
+    status = "needs_check";
+  } else {
+    status = "uncertain";
+  }
+
+  return { score: clamped, status };
+}
+
 /** Pick the most urgent trust state from a list (used for household summary). */
 export function worstTrustState(states: TrustState[]): TrustState {
   const order: TrustState[] = ["stale", "decaying", "unverified", "trusted"];