Add domme-converters/assets/js/store.js

domme-converters/assets/js/store.js

@@ -0,0 +1,110 @@
+"use strict";
+
+/**
+ * Winkelmandje-store met persistentie in localStorage en een eenvoudig
+ * publish/subscribe-mechanisme. Alle pagina's delen dezelfde toestand, zodat
+ * het mandje behouden blijft tijdens het navigeren.
+ */
+(function () {
+  const STORAGE_KEY = "converterland.cart.v1";
+  const TAX_RATE = 0.21;
+
+  const CL = (window.CL = window.CL || {});
+  const products = window.PRODUCTS || [];
+  const findProduct = (id) => products.find((p) => p.id === id);
+
+  /** @type {Map<string, number>} product-id -> aantal */
+  const cart = new Map();
+  const listeners = new Set();
+
+  function load() {
+    try {
+      const raw = localStorage.getItem(STORAGE_KEY);
+      if (!raw) return;
+      const entries = JSON.parse(raw);
+      if (Array.isArray(entries)) {
+        for (const [id, qty] of entries) {
+          if (findProduct(id) && Number.isFinite(qty) && qty > 0) {
+            cart.set(id, Math.floor(qty));
+          }
+        }
+      }
+    } catch (err) {
+      // Beschadigde opslag negeren en met een leeg mandje starten.
+    }
+  }
+
+  function persist() {
+    try {
+      localStorage.setItem(STORAGE_KEY, JSON.stringify([...cart.entries()]));
+    } catch (err) {
+      // Opslag kan geblokkeerd zijn (privémodus); de store werkt dan in-memory.
+    }
+  }
+
+  function emit() {
+    persist();
+    for (const fn of listeners) fn();
+  }
+
+  const store = {
+    TAX_RATE,
+
+    subscribe(fn) {
+      listeners.add(fn);
+      return () => listeners.delete(fn);
+    },
+
+    entries() {
+      return [...cart.entries()];
+    },
+
+    size() {
+      return cart.size;
+    },
+
+    quantityOf(id) {
+      return cart.get(id) || 0;
+    },
+
+    add(id, amount = 1) {
+      const product = findProduct(id);
+      if (!product) return;
+      cart.set(id, (cart.get(id) || 0) + amount);
+      emit();
+    },
+
+    setQuantity(id, qty) {
+      if (!findProduct(id)) return;
+      if (qty <= 0) cart.delete(id);
+      else cart.set(id, Math.floor(qty));
+      emit();
+    },
+
+    step(id, delta) {
+      if (!cart.has(id)) return;
+      this.setQuantity(id, cart.get(id) + delta);
+    },
+
+    clear() {
+      cart.clear();
+      emit();
+    },
+
+    totals() {
+      let count = 0;
+      let subtotal = 0;
+      for (const [id, qty] of cart) {
+        const product = findProduct(id);
+        if (!product) continue;
+        count += qty;
+        subtotal += product.price * qty;
+      }
+      const tax = subtotal * TAX_RATE;
+      return { count, subtotal, tax, total: subtotal + tax };
+    },
+  };
+
+  load();
+  CL.store = store;
+})();