Fas 3 steg 3b: minimala efterfrågor + hushållsantagandeprofiler per ingrediens

packages/inventory-engine/src/cooking-profiles.ts

@@ -0,0 +1,64 @@
+/**
+ * Antagandeprofiler för matlagning (Fas 3 §6.2).
+ * Rensa, deterministiska funktioner för att uppdatera per-hushålls-per-ingrediens-profiler
+ * utifrån faktiska svar efter en cooking session.
+ */
+
+export interface ProfileUpdateInput {
+  householdId: string;
+  canonicalIngredientId: string;
+  plannedPortions: number;
+  actualPortionsEaten: number;
+  leftoverEstimatePortions: number;
+  sessionId: string;
+  date: string;
+}
+
+export interface ExistingProfile {
+  averageEatenPortions: number | null;
+  averageLeftoverPortions: number | null;
+  observationCount: number;
+  lastSessionAnswers?: Array<{ sessionId: string; eaten: number; leftovers: number; date: string }> | null;
+}
+
+/**
+ * Beräkna nya profilvärden med exponentiellt glidande medelvärde.
+ * alpha = 1 / (observationCount + 1) ger jämn viktning över tid.
+ */
+export function updateCookingAssumptionProfile(
+  input: ProfileUpdateInput,
+  existing: ExistingProfile,
+): {
+  averageEatenPortions: number;
+  averageLeftoverPortions: number;
+  observationCount: number;
+  lastSessionAnswers: Array<{ sessionId: string; eaten: number; leftovers: number; date: string }>;
+} {
+  const eaten = clamp(input.actualPortionsEaten, 0, input.plannedPortions);
+  const leftovers = clamp(input.leftoverEstimatePortions, 0, input.plannedPortions - eaten);
+
+  const prevEaten = existing.averageEatenPortions ?? eaten;
+  const prevLeftovers = existing.averageLeftoverPortions ?? leftovers;
+  const prevCount = existing.observationCount ?? 0;
+
+  const alpha = 1 / (prevCount + 1);
+  const averageEatenPortions = round2(prevEaten + alpha * (eaten - prevEaten));
+  const averageLeftoverPortions = round2(prevLeftovers + alpha * (leftovers - prevLeftovers));
+  const observationCount = prevCount + 1;
+
+  const history = existing.lastSessionAnswers ?? [];
+  const lastSessionAnswers = [
+    { sessionId: input.sessionId, eaten, leftovers, date: input.date },
+    ...history,
+  ].slice(0, 10);
+
+  return { averageEatenPortions, averageLeftoverPortions, observationCount, lastSessionAnswers };
+}
+
+function clamp(n: number, min: number, max: number): number {
+  return Math.max(min, Math.min(max, n));
+}
+
+function round2(n: number): number {
+  return Math.round(n * 100) / 100;
+}

packages/inventory-engine/src/index.ts

@@ -6,3 +6,4 @@ export * from "./forecast.js";
 export * from "./trust.js";
 export * from "./reconciliation.js";
 export * from "./scan-diff.js";
+export * from "./cooking-profiles.js";