Invoices can be created

- Transactions can now be tracked

src/models/invoice/invoice.schema.ts

@@ -0,0 +1,58 @@
+import { NativeError, Schema, SchemaTypes } from 'mongoose';
+import { CryptoUnits, FiatUnits, PaymentStatus } from '../../helper/types';
+import { IInvoice } from './invoice.interface';
+
+const urlRegex = /((([A-Za-z]{3,9}:(?:\/\/)?)(?:[\-;:&=\+\$,\w]+@)?[A-Za-z0-9\.\-]+|(?:www\.|[\-;:&=\+\$,\w]+@)[A-Za-z0-9\.\-]+)((?:\/[\+~%\/\.\w\-_]*)?\??(?:[\-\+=&;%@\.\w_]*)#?(?:[\.\!\/\\\w]*))?)/
+
+const schemaCart = new Schema({
+    price: { type: Number, required: true },
+    name: { type: String, trim: true, required: true },
+    image: { type: String, match: urlRegex, required: true },
+    quantity: { type: Number, default: 1 }
+})
+
+const schemaInvoice = new Schema({
+    paymentMethods: [{ type: String, enum: Object.values(CryptoUnits), default: [CryptoUnits.BITCOIN], required: true }],
+    receiveAddress: { type: String, required: true },
+    paidWith: { type: String, enum: CryptoUnits },
+    transcationHash: { type: String, required: false },
+    cart: [{ type: schemaCart, required: false }],
+    totalPrice: { type: Number, required: false },
+    currency: { type: String, enum: Object.values(FiatUnits), required: false },
+    dueBy: { type: Number, required: true },
+    status: { type: Number, enum: Object.values(PaymentStatus), default: PaymentStatus.PENDING },
+    email: { type: String, required: false },
+    successUrl: { type: String, match: urlRegex, required: false },
+    cancelUrl: { type: String, match: urlRegex, required: false }
+}, {
+    timestamps: {
+        createdAt: true,
+    },
+    versionKey: false
+});
+
+// Validate values
+schemaInvoice.post('validate', function (res, next) {
+    let self = this as IInvoice;
+    
+    // If cart is undefined and price too, error.
+    if ((self.cart === undefined || self.cart.length === 0) && self.totalPrice === undefined) {
+        next(new Error('Either cart or price has to be defined!'));
+        return;
+    }
+
+    // If cart is provided, calculate price.
+    if (self.cart !== undefined && self.totalPrice === undefined) {
+        let totalPrice = 0;
+        
+        for (let i = 0; i < self.cart.length; i++) {
+            const item = self.cart[i];
+            totalPrice += item.price * item.quantity;
+        }
+
+        self.set({ totalPrice });
+    }
+    next();
+})
+
+export { schemaInvoice }