refactor products as type.

lib/product.ts

@@ -1,6 +1,4 @@
 import uuid from "react-native-uuid";
-import { Area } from "convert";
-import { Transform } from "class-transformer";
 import { dimensions_t, area_t } from "./dimensions";
 import { matchDimensions } from "./dimensions";
 
@@ -15,85 +13,66 @@ export type ProductAttributes = {
     description?: string,
     depth?: string,
     currency?: Currency,
-    // [index:string]: any,
+    [index:string]: any,
 }
 export function dimensionArea(d: dimensions_t) {
     return "w" in d ? d.w * d.l : 0;
 }
 
-export type ProductData = {
+export type product_type_t = "lumber" | "area_rug"
+
+export type Product = {
     id?: Id;
     pricePerUnit: number;
     dimensions: dimensions_t;
+    type: product_type_t;
     attributes?: ProductAttributes;
 };
 
-
+export type LumberProduct = Product & {
-export class Product {
+    type: "lumber"
-
-    public id?: Id;
-
-    constructor(public pricePerUnit: number, public dimensions: dimensions_t, public attributes: ProductAttributes = {},
-        id?: Id,
-    ) {
-        this.id = id || uuid.v4().toString();
 }
 
-    public priceFor(dimensions: dimensions_t, damage : number): number {
+export type AreaRugProduct = Product & {
+    type: "lumber"
+}
+
+export function productPriceFor(product : Product, dimensions: dimensions_t, damage: number): number {
     if (Number.isNaN(damage)) damage = 0;
-        const dim = matchDimensions(dimensions, this.dimensions);
+    const dim = matchDimensions(dimensions, product.dimensions);
     return (
-            dim.w ? dimensionArea(dim) / dimensionArea(this.dimensions) * this.pricePerUnit
+        dim.w ? dimensionArea(dim) / dimensionArea(product.dimensions) * product.pricePerUnit
-                : (dim.l / this.dimensions.l) * this.pricePerUnit
+            : (dim.l / product.dimensions.l) * product.pricePerUnit
     ) * (1.0 - damage);
 }
 
-    get priceDisplay() {
+export function priceDisplay(price : number) {
-        return this.pricePerUnit.toLocaleString(undefined, {
+    return price.toLocaleString(undefined, {
         minimumFractionDigits: 2,
         maximumFractionDigits: 2,
     })
 }
 
-    get pricePerUnitDisplay() {
+export function pricePerUnitDisplay(product : Product) {
-        const p = this.priceDisplay;
+        const p = priceDisplay(product.pricePerUnit);
-        const { l, u } = this.dimensions;
+        const { l, u } = product.dimensions;
-        const w = (this.dimensions as area_t).w || null;
+        const w = (product.dimensions as area_t).w || null;
         const d = w ? `${l}${u} x ${w}${u}` : `${l}${u}`;
         return `$${p} per ${d}`
 }
 
-    get attributesAsList() {
+export function attributesAsList(attributes : {[key:string]: any}) {
-        return Object.entries(this.attributes).map(([key, value]) => {
+    return Object.entries(attributes).map(([key, value]) => {
         return { key, value }
     })
 }
 
-    public removeAttribute(key: string) {
+export function removeAttribute(attributes: {[key: string]: any}, key: string) {
-        this.attributes = Object.fromEntries(
+    return Object.fromEntries(
-            Object.entries(this.attributes).filter(
+        Object.entries(attributes).filter(
             ([k, v]) => {
                 k == key;
             }
         )
     );
 }
-
-    get asObject(): ProductData {
-        return {
-            id: this.id,
-            pricePerUnit: this.pricePerUnit,
-            dimensions: this.dimensions,
-            attributes: this.attributes,
-        }
-    }
-
-    static fromObject({ id, pricePerUnit, dimensions, attributes }: ProductData) {
-        return new Product(
-            pricePerUnit,
-            dimensions,
-            attributes,
-            id,
-        )
-    }
-}