Major api changes

- Remove of confirmation listener in providers
- Random selector has been capped down to 32 characters
- Monero is now semi-supported

src/app.ts

@@ -32,10 +32,9 @@ export let providerManager: ProviderManager = undefined;
 export let logger: winston.Logger;
 
 async function run() {
-    const { combine, timestamp, label, printf, prettyPrint } = winston.format;
+    const { combine, timestamp, printf, prettyPrint } = winston.format;
 
-    const myFormat = printf(({ level, message, label, timestamp }) => {
+    const myFormat = printf(({ level, message, timestamp }) => {
-        if (label !== undefined) return `${timestamp} ${level} (${label}) ${message}`;
         return `${timestamp} ${level} ${message}`;
     });
 

src/controllers/invoice.ts

@@ -90,7 +90,7 @@ export async function createInvoice(req: Request, res: Response) {
     const dueBy = new Date(Date.now() + 1000 * 60 * 15);    
     
     Invoice.create({
-        selector: randomString(128),
+        selector: randomString(32),
         paymentMethods,
         successUrl,
         cancelUrl,

src/helper/backendProvider.ts

@@ -1,3 +1,4 @@
+import { invoiceManager, providerManager } from '../app';
 import { IInvoice } from '../models/invoice/invoice.interface';
 import { CryptoUnits } from './types';
 
@@ -34,9 +35,10 @@ export abstract class BackendProvider {
     /**
      * Get a transaction from the blockchain.
      * @param txId Hash of the transcation you're looking for.
+     * @param context Invoice for context (required to calculate correct amount)
      * @returns See https://developer.bitcoin.org/reference/rpc/gettransaction.html for reference
      */
-    abstract getTransaction(txId: string): Promise<ITransaction>;
+    abstract getTransaction(txId: string, context?: IInvoice): Promise<ITransaction | null>;
 
     /**
      * Decode a raw transcation that was broadcasted in the network.
@@ -66,11 +68,6 @@ export abstract class BackendProvider {
      */
     abstract listener(): void;
 
-    /**
-     * Keep track of unconfirmed transactions.
-     */
-    abstract watchConfirmations(): void;
-
     /**
      * Provided is an array with pending invoices that have to be check.
      * 
@@ -93,21 +90,21 @@ export interface ITransactionDetails {
 }
 
 export interface ITransaction {
-    amount: number;
+    id: string;
-    fee: number;
+    blockhash: string;
+    amount: number;                 // Total transaction amount
+    fee?: number;
     confirmations: number;
     time: number;                   // Unix timestamp
-    details: ITransactionDetails[];
+    details?: ITransactionDetails[]; // In-/and Outputs of an transaction
-    hex: string;
 }
 
 // Special interface for RPC call `listreceivedbyaddress`
 export interface ITransactionList {
-    address: string;
+    address: string;        // Address that performed that action
-    amount: number;
+    amount: number;         // Amount that got transfered
     confirmation: number;
-    label: string;
+    txids?: string[];
-    txids: string[];
 }
 
 export interface IRawTransaction {

src/helper/invoiceManager.ts

@@ -21,15 +21,24 @@ export class InvoiceManager {
             logger.info(`There are ${invoices.length} invoices that are pending or unconfirmed`);
 
             invoices.forEach(invoice => {
+                if (invoice.status === PaymentStatus.DONE || invoice.status === PaymentStatus.CANCELLED) {
+                    this.removeInvoice(invoice);
+                    return;
+                }
+
+                if (invoice.status === PaymentStatus.PENDING) { this.pendingInvoices.push(invoice); }
+                if (invoice.status === PaymentStatus.UNCONFIRMED) { this.unconfirmedTranscations.push(invoice); }
+
                 providerManager.getProvider(invoice.paymentMethod).validateInvoice(invoice);
             });
         });
 
         this.expireScheduler();
+        this.watchConfirmations();
     }
 
     /**
-     * This function is basicly close all invoices that have not been paid in time.
+     * This function will basicly close all invoices that have not been paid in time.
      */
     private expireScheduler() {
         setInterval(async () => {
@@ -144,8 +153,26 @@ export class InvoiceManager {
         }
     }
 
+    /**
+     * This mehtod, once started, will check every n-seconds if the confirmation
+     * count of one unconfirmed transcation has changed.
+     */
+    async watchConfirmations() {
+        setInterval(() => {
+            this.unconfirmedTranscations.forEach(async invoice => {
+                const transcation = invoice.transcationHash;
+                
+                const provider = providerManager.getProvider(invoice.paymentMethod);
+                const tx = await provider.getTransaction(transcation);
+                this.setConfirmationCount(invoice, tx.confirmations);
+            });
+        }, 2_000);
+    }
+
     /**
      * This method checks if a payment has been made in time and that the right amount was sent.
+     * 
+     * **Only issue this method in the moment the payment has been made.**
      */
     async validatePayment(invoice: IInvoice, tx: string): Promise<void> {
         if (invoice.dueBy.getTime() < Date.now() && invoice.status <= PaymentStatus.PENDING && invoice.status >= PaymentStatus.REQUESTED) {
@@ -155,16 +182,13 @@ export class InvoiceManager {
             return; // Payment is too late
         }
 
-        const txInfo = await providerManager.getProvider(invoice.paymentMethod).getTransaction(tx);
+        const txInfo = await providerManager.getProvider(invoice.paymentMethod).getTransaction(tx, invoice);
-        const receivedTranscation = txInfo.details.find(detail => {
-            return (detail.address == invoice.receiveAddress && detail.amount > 0);    // We only want receiving transactions
-        });
         
         const price = this.getPriceByInvoice(invoice);
-        if (price === undefined) return;
+        if (price === 0) return;
 
-        // Transaction sent enough funds
+        // Sent enough funds
-        if (receivedTranscation.amount == price || receivedTranscation.amount > price) {
+        if (txInfo.amount == price || txInfo.amount > price) {
             invoice.transcationHash = tx;
             await invoice.save();
 
@@ -176,40 +200,12 @@ export class InvoiceManager {
              * know who the original sender was. Therefore if a customer sent not the right amount, he/she
              * should contact the support of the shop.
              */
-            logger.warning(`Transaction (${tx}) did not sent requested funds. (sent: ${receivedTranscation.amount} BTC, requested: ${price} BTC)`);
+            logger.warning(`Transaction (${tx}) did not sent requested funds. (sent: ${txInfo.amount}, requested: ${price})`);
             invoice.status = PaymentStatus.TOOLITTLE;
 
             await invoice.save();
 
             return;
-
-            // This is dead code and only exists because I'm yet unsure what to do with such payments.
-            let sendBack = receivedTranscation.amount;
-
-            // If the amount was too much, mark invoice as paid and try to send remaining funds back.
-            if (receivedTranscation.amount > price) {
-                sendBack = price - txInfo.amount;
-
-                // Sent amount was too much but technically the bill is paid (will get saved in upgradeInvoice)
-                invoice.transcationHash = tx;
-
-                this.upgradeInvoice(invoice);
-            }
-            
-            // We only have one input, we can be sure that the sender will receive the funds
-            if (txInfo.details.length === 1) {
-                if (txInfo.details[0].address.length !== 1) return;
-
-                const txBack = await providerManager.getProvider(invoice.paymentMethod).sendToAddress(txInfo.details[0].address[0], receivedTranscation.amount, null, null, true);
-                logger.info(`Sent ${receivedTranscation.amount} ${invoice.paymentMethod} back to ${txInfo.details[0].address[0]}: ${txBack}`);
-            } else {
-                // If we cannot send the funds back, save transaction id and mark invoice as failed.
-                invoice.transcationHash = tx;
-                invoice.status = PaymentStatus.TOOLITTLE;
-                this.removeInvoice(invoice);
-
-                await invoice.save();
-            }
         }
     }
 }

src/helper/providerManager.ts

@@ -1,7 +1,7 @@
 import { readdirSync } from 'fs';
 import { join } from 'path';
 import { config } from '../../config';
-import { invoiceManager, logger } from '../app';
+import { invoiceManager, logger, providerManager } from '../app';
 import { BackendProvider } from './backendProvider';
 import { CryptoUnits } from './types';
 
@@ -57,15 +57,16 @@ export class ProviderManager {
     /**
      * This provider will be no longer be used.
      */
-    disable(providerFor: CryptoUnits) {
+    disable(name: string) {
-        if (!this.cryptoProvider.has(providerFor)) {
+        this.cryptoProvider.forEach(provider => {
-            return;
+            if (provider.NAME === name) {
+                // Disable all coins that are supported by this provider.
+                provider.CRYPTO.forEach(crypto => {
+                    this.cryptoProvider.delete(crypto);
+                });
+                logger.warning(`Provider "${provider.NAME}" is now disabled.`);
             }
-
+        });
-        const provider = this.getProvider(providerFor);
-        logger.warn(`Provider "${provider.NAME}" will be disabled ...`);
-
-        this.cryptoProvider.delete(providerFor);
     }
 
 }

src/helper/providers/bitcoinCore.ts

@@ -3,7 +3,7 @@ import { Subscriber } from 'zeromq';
 import * as rpc from 'jayson';
 import { invoiceManager, logger } from '../../app';
 import { IInvoice } from '../../models/invoice/invoice.interface';
-import { BackendProvider, IRawTransaction, ITransaction, ITransactionList } from '../backendProvider';
+import { BackendProvider, IRawTransaction, ITransaction, ITransactionDetails, ITransactionList } from '../backendProvider';
 import { CryptoUnits, PaymentStatus } from '../types';
 
 export class Provider implements BackendProvider {
@@ -29,11 +29,8 @@ export class Provider implements BackendProvider {
         });
 
         this.listener();
-        this.watchConfirmations();
 
         return true;
-
-        //logger.info('The Bitcoin Core backend is now available!');
     }
 
     async getNewAddress(): Promise<string> {
@@ -49,7 +46,7 @@ export class Provider implements BackendProvider {
         });
     }
 
-    async getTransaction(txId: string): Promise<ITransaction> {
+    async getTransaction(txId: string, context?: IInvoice): Promise<ITransaction> {
         return new Promise<ITransaction>((resolve, reject) => {
             this.rpcClient.request('gettransaction', [txId], (err, message) => {
                 if (err) {
@@ -57,7 +54,28 @@ export class Provider implements BackendProvider {
                     return;
                 }
 
-                resolve(message.result);
+                // Calculate received funds
+                const details: ITransactionDetails[] = message.result.details;
+                let amount = 0;
+
+                if (context !== undefined) {
+                    for (let i = 0; i < details.length; i++) {
+                        if (details[i].category == 'receive' && details[i].address == context.receiveAddress) {
+                            amount += details[i].amount;
+                        }
+                    }
+                }
+
+                const ret: ITransaction = {
+                    id: message.result.txid,
+                    amount,
+                    blockhash: message.result.blockhash,
+                    confirmations: message.result.confirmations,
+                    time: message.result.time,
+                    fee: message.result.fee
+                }
+    
+                resolve(ret);
             });
         });
     }
@@ -107,7 +125,6 @@ export class Provider implements BackendProvider {
                     logger.debug(`${output.scriptPubKey.addresses} <-> ${invoice.receiveAddress}`);
                     // We found our transaction (https://developer.bitcoin.org/reference/rpc/decoderawtransaction.html)
                     if (output.scriptPubKey.addresses.indexOf(invoice.receiveAddress) !== -1) {
-                        const senderAddress = output.scriptPubKey.addresses[output.scriptPubKey.addresses.indexOf(invoice.receiveAddress)];
                         logger.info(`Transcation for invoice ${invoice.id} received! (${tx.hash})`);
 
                         // Change state in database
@@ -119,20 +136,7 @@ export class Provider implements BackendProvider {
         }
     }
     
-    async watchConfirmations() {
-        setInterval(() => {
-            invoiceManager.getUnconfirmedTransactions().filter(item => { return item.paymentMethod === CryptoUnits.BITCOIN }).forEach(async invoice => {
-                if (invoice.transcationHash.length === 0) return;
-                const transcation = invoice.transcationHash;
-                
-                const tx = await this.getTransaction(transcation);
-                invoiceManager.setConfirmationCount(invoice, tx.confirmations);
-            });
-        }, 2_000);
-    }
-    
     async validateInvoice(invoice: IInvoice) {
-        if (invoice.status === PaymentStatus.DONE || invoice.status === PaymentStatus.CANCELLED) return;
         if (invoice.paymentMethod !== CryptoUnits.BITCOIN) return;
 
         this.rpcClient.request('listreceivedbyaddress', [0, false, false, invoice.receiveAddress], async (err, message) => {

src/helper/providers/dogecoinCore.ts

@@ -29,7 +29,6 @@ export class Provider implements BackendProvider {
         });
 
         this.listener();
-        this.watchConfirmations();
 
         return true;
 
@@ -49,7 +48,7 @@ export class Provider implements BackendProvider {
         });
     }
 
-    async getTransaction(txId: string): Promise<ITransaction> {
+    async getTransaction(txId: string, context?: IInvoice): Promise<ITransaction> {
         return new Promise<ITransaction>((resolve, reject) => {
             this.rpcClient.request('gettransaction', [txId], (err, message) => {
                 if (err) {
@@ -57,7 +56,26 @@ export class Provider implements BackendProvider {
                     return;
                 }
 
-                resolve(message.result);
+                // Calculate received funds
+                const details: ITransactionDetails[] = message.result.details;
+                let amount = 0;
+
+                details.forEach(detail => {
+                    if (detail.category === 'receive' && detail.address === context.receiveAddress) {
+                        amount += detail.amount;
+                    }
+                })
+
+                const ret: ITransaction = {
+                    id: message.result.txid,
+                    amount,
+                    blockhash: message.result.blockhash,
+                    confirmations: message.result.confirmations,
+                    time: message.result.time,
+                    fee: message.result.fee
+                }
+    
+                resolve(ret);
             });
         });
     }
@@ -119,20 +137,7 @@ export class Provider implements BackendProvider {
         }
     }
     
-    async watchConfirmations() {
-        setInterval(() => {
-            invoiceManager.getUnconfirmedTransactions().filter(item => { return item.paymentMethod === CryptoUnits.DOGECOIN }).forEach(async invoice => {
-                if (invoice.transcationHash.length === 0) return;
-                const transcation = invoice.transcationHash;
-                
-                const tx = await this.getTransaction(transcation);
-                invoiceManager.setConfirmationCount(invoice, tx.confirmations);
-            });
-        }, 2_000);
-    }
-    
     async validateInvoice(invoice: IInvoice) {
-        if (invoice.status === PaymentStatus.DONE || invoice.status === PaymentStatus.CANCELLED) return;
         if (invoice.paymentMethod !== CryptoUnits.DOGECOIN) return;
 
         this.rpcClient.request('listreceivedbyaddress', [0, false, false], async (err, message) => {

src/helper/providers/litecoinCore.ts

@@ -3,7 +3,7 @@ import { Subscriber } from 'zeromq';
 import * as rpc from 'jayson';
 import { invoiceManager, logger } from '../../app';
 import { IInvoice } from '../../models/invoice/invoice.interface';
-import { BackendProvider, IRawTransaction, ITransaction, ITransactionList } from '../backendProvider';
+import { BackendProvider, IRawTransaction, ITransaction, ITransactionDetails, ITransactionList } from '../backendProvider';
 import { CryptoUnits, PaymentStatus } from '../types';
 
 export class Provider implements BackendProvider {
@@ -29,7 +29,6 @@ export class Provider implements BackendProvider {
         });
 
         this.listener();
-        this.watchConfirmations();
 
         return true;
     }
@@ -47,7 +46,7 @@ export class Provider implements BackendProvider {
         });
     }
 
-    async getTransaction(txId: string): Promise<ITransaction> {
+    async getTransaction(txId: string, context?: IInvoice): Promise<ITransaction> {
         return new Promise<ITransaction>((resolve, reject) => {
             this.rpcClient.request('gettransaction', [txId], (err, message) => {
                 if (err) {
@@ -55,7 +54,26 @@ export class Provider implements BackendProvider {
                     return;
                 }
 
-                resolve(message.result);
+                // Calculate received funds
+                const details: ITransactionDetails[] = message.result.details;
+                let amount = 0;
+
+                details.forEach(detail => {
+                    if (detail.category === 'receive' && detail.address === context.receiveAddress) {
+                        amount += detail.amount;
+                    }
+                })
+
+                const ret: ITransaction = {
+                    id: message.result.txid,
+                    amount,
+                    blockhash: message.result.blockhash,
+                    confirmations: message.result.confirmations,
+                    time: message.result.time,
+                    fee: message.result.fee
+                }
+    
+                resolve(ret);
             });
         });
     }
@@ -117,18 +135,6 @@ export class Provider implements BackendProvider {
         }
     }
     
-    async watchConfirmations() {
-        setInterval(() => {
-            invoiceManager.getUnconfirmedTransactions().filter(item => { return item.paymentMethod === CryptoUnits.LITECOIN }).forEach(async invoice => {
-                if (invoice.transcationHash.length === 0) return;
-                const transcation = invoice.transcationHash;
-                
-                const tx = await this.getTransaction(transcation);
-                invoiceManager.setConfirmationCount(invoice, tx.confirmations);
-            });
-        }, 2_000);
-    }
-    
     async validateInvoice(invoice: IInvoice) {
         if (invoice.status === PaymentStatus.DONE || invoice.status === PaymentStatus.CANCELLED) return;
         if (invoice.paymentMethod !== CryptoUnits.LITECOIN) return;

src/helper/providers/moneroCLI.js

@@ -1,85 +0,0 @@
-import * as rpc from 'jayson';
-import { Subscriber } from 'zeromq';
-
-import { logger, providerManager } from '../../app';
-import { BackendProvider, ITransaction } from '../backendProvider';
-import { CryptoUnits } from '../types';
-
-export class Provider implements BackendProvider {
-
-    private sock: Subscriber;
-    private rpcClient: rpc.HttpClient;
-
-    NAME = 'Monero CLI';
-    DESCRIPTION = 'This provider queries the Monero daemon running on your computer';
-    AUTHOR = 'LibrePay Team';
-    VERSION = '1.0';
-    CRYPTO = CryptoUnits.MONERO;
-
-    onEnable() {
-        logger.info('Monero CLI provider is now availabe!');
-
-        if (process.env.MONERO_WALLET_PASSWORD === undefined) {
-            logger.error(`Enviroment variable MONERO_WALLET_PASSWORD is required but not set!`);
-            return false;
-        }
-
-        if (process.env.MONERO_WALLET_NAME === undefined) {
-            logger.error(`Enviroment variable MONERO_WALLET_FILEPATH is required but not set!`);
-            return false;
-        }
-
-        if (process.env.MONERO_RPC_ADDRESS === undefined) {
-            logger.error(`Enviroment variable MONERO_RPC_ADDRESS is required but not set!`);
-            return false;
-        }
-
-        this.rpcClient = rpc.Client.http({
-            port: 18082,
-            version: 2,
-            auth: 'admin:admin'        
-        });
-        this.rpcClient.request('open_wallet', {
-            filename: process.env.MONERO_WALLET_NAME,
-            password: process.env.MONERO_WALLET_PASSWORD
-        }, (err, message) => {
-            if (err) {
-                logger.error(`Failed to open Monero wallet: ${err.message}\nMaybe a wrong password or path?`);
-                providerManager.disable(this.CRYPTO);
-                
-                return;
-            }
-            console.log(message);
-        });
-
-        this.listener();
-
-        return true;
-    }
-
-    listener() {
-        this.sock = new Subscriber();
-        this.sock.connect(process.env.MONERO_RPC_ADDRESS);
-        this.sock.subscribe('rawtx');
-    }
-
-    // Since we can safely use the same address everytime, we just need to return a address
-    // with an integrated payment id.
-    getNewAddress(): Promise<string> {
-        return new Promise<string>((resolve, reject) => {
-            const account_index = Number(process.env.MONERO_WALLET_ACCOUNT_INDEX) || 0;
-            this.rpcClient.request('make_integrated_address', {}, async (err, message) => {
-                if (err) {
-                    reject(err);
-                    return;
-                }
-    
-                resolve(message.result.integrated_address);
-            });
-        });
-    }
-
-    async getTransaction(txId: string): Promise<ITransaction> {
-        
-    }
-}

src/helper/providers/moneroCLI.ts

@@ -0,0 +1,217 @@
+import * as rpc from 'jayson';
+import { Subscriber } from 'zeromq';
+
+import { invoiceManager, logger } from '../../app';
+import { IInvoice } from '../../models/invoice/invoice.interface';
+import { Invoice } from '../../models/invoice/invoice.model';
+import { BackendProvider, ITransaction } from '../backendProvider';
+import { CryptoUnits } from '../types';
+
+export class Provider implements BackendProvider {
+
+    private sock: Subscriber;
+    private rpcClient: rpc.HttpClient;
+
+    NAME = 'Monero RPC Wallet';
+    DESCRIPTION = 'This provider queries the Monero daemon running on your computer';
+    AUTHOR = 'LibrePay Team';
+    VERSION = '0.1';
+    CRYPTO = [CryptoUnits.MONERO];
+
+    onEnable() {
+        if (process.env.MONERO_WALLET_PASSWORD === undefined) {
+            logger.error(`Enviroment variable MONERO_WALLET_PASSWORD is required but not set!`);
+            return false;
+        }
+
+        if (process.env.MONERO_WALLET_NAME === undefined) {
+            logger.error(`Enviroment variable MONERO_WALLET_FILEPATH is required but not set!`);
+            return false;
+        }
+
+        if (process.env.MONERO_ZMQ_ADDRESS === undefined) {
+            logger.error(`Enviroment variable MONERO_ZMQ_ADDRESS is required but not set!`);
+            return false;
+        }
+
+        this.rpcClient = rpc.Client.http({
+            path: '/json_rpc',
+            port: 38085
+        });
+        this.rpcClient.request('open_wallet', {
+            filename: process.env.MONERO_WALLET_NAME,
+            password: process.env.MONERO_WALLET_PASSWORD
+        }, (err, message) => {
+            if (err) {
+                console.log(err);
+                logger.error(`Failed to open Monero wallet: ${err}\nMaybe a wrong password or path?`);
+                return;
+            }
+        });
+
+        this.listener();
+
+        return true;
+    }
+
+    async listener() {
+        // Since we can't really use the ZeroMQ interface, we have to query every n-seconds.
+        // Technically there is a ZeroMQ interface but there is almost no to zero documentation for it.
+        setInterval(() => {
+            invoiceManager.getPendingInvoices().forEach(async invoice => {
+                if (invoice.paymentMethod !== CryptoUnits.MONERO) return;
+                
+                const tx = await this.getPaymentById(((await this.splitAddress(invoice.receiveAddress)).paymentId));
+                if (tx === null) {
+                    return;
+                }
+
+                logger.info(`Transcation for invoice ${invoice.id} received!`);
+                invoiceManager.validatePayment(invoice, tx.id);
+            });
+        }, 5_000);
+    }
+
+    // Since we can safely use the same address everytime, we just need to return a address
+    // with an integrated payment id.
+    getNewAddress(): Promise<string> {
+        return new Promise<string>((resolve, reject) => {
+            const account_index = Number(process.env.MONERO_WALLET_ACCOUNT_INDEX) || 0;
+            this.rpcClient.request('make_integrated_address', {}, async (err, message) => {
+                if (err) {
+                    reject(err);
+                    return;
+                }
+    
+                resolve(message.result.integrated_address);
+            });
+        });
+    }
+
+    /**
+     * @returns If a payment has not been made yet, `null` will be returned.
+     */
+    async getTransaction(txid: string, context?: IInvoice): Promise<ITransaction | null> {
+        return new Promise<ITransaction>(async (resolve, reject) => {            
+            // We're still missing the confirmation count, since we don't get it with this function.
+            this.rpcClient.request('get_transfer_by_txid', { txid }, async (err, message) => {
+                if (err) {
+                    reject(err);
+                    return;
+                }
+
+                const paymentTransaction = message.result.transfer;
+                if (paymentTransaction === undefined) {
+                    console.log(message)
+                    logger.warning(`Tried to get transfer by txid but failed: ${message}`);
+                    resolve(null);
+                    return;
+                }
+
+                // Renaming properties to make them fit into interface.
+                const ret: ITransaction = {
+                    id: paymentTransaction.txid,
+                    blockhash: paymentTransaction.txid,
+                    amount: this.decimalToFloat(paymentTransaction.amount),
+                    confirmations: paymentTransaction.confirmations,
+                    time: paymentTransaction.timestamp,
+                    fee: paymentTransaction.fee
+                };
+                resolve(ret);
+            });
+        });
+    }
+
+    sendToAddress(
+        recipient: string,
+        amount: number,
+        comment?: string,
+        commentTo?: string,
+        subtractFeeFromAmount?: boolean): Promise<string> {
+            return new Promise<string>((resolve, reject) => {
+                const account_index = Number(process.env.MONERO_WALLET_ACCOUNT_INDEX) || 0;
+                this.rpcClient.request('transfer', { destinations: [{ amount, address: recipient }] }, async (err, message) => {
+                    if (err) {
+                        reject(err);
+                        return;
+                    }
+                    
+                    logger.debug(`[Monero] Transaction has been made: ${message.result.tx_hash}`);
+                    resolve(message.result.tx_hash);
+                });
+            });
+        }
+
+    async validateInvoice(invoice: IInvoice) {
+        if (invoice.paymentMethod !== CryptoUnits.MONERO) return;
+
+        const split = await this.splitAddress(invoice);
+        if (split === null) {
+            return;
+        }
+        
+        const transaction = await this.getPaymentById(split.paymentId);
+
+        if (transaction === null) {
+            return; // Transaction has not been yet made.
+        }
+        
+        invoiceManager.validatePayment(invoice, transaction.blockhash);
+        /*this.rpcClient.request('get_payments', { payment_id }, async (err, message) => {
+            if (err) {
+                logger.error(`[Monero] There was an error while gettings payments of ${payment_id}: ${err}`);
+                return;
+            }
+
+            const payment = message.result.payments[0];
+            invoiceManager.validatePayment(invoice, payment.tx_hash);
+        });*/
+    }
+
+    private getPaymentById(payment_id: string): Promise<ITransaction> {
+        return new Promise(resolve => {
+            this.rpcClient.request('get_payments', { payment_id: payment_id }, async (err, message) => {
+                if (err) {
+                    resolve(null);
+                    return;
+                }
+    
+                console.log(payment_id, message);                
+    
+                // The payment has not been made yet
+                if (message.result.payments === undefined) {
+                    resolve(null);
+                    return;
+                }
+    
+                resolve(await this.getTransaction(message.result.payments[0].tx_hash));
+            });
+        })
+    }
+
+    /**
+     * This method will take the full receive address and will return the payment id and orignal address.
+     * @returns Will return `null` if input was invalid.
+     */
+    private splitAddress(context: IInvoice | string): Promise<{ address: string, paymentId: string } | null> {
+        return new Promise(resolve => {
+            const address = typeof(context) === 'string' ? context : context.receiveAddress;
+            this.rpcClient.request('split_integrated_address', { integrated_address: address }, async (err, message) => {
+                if (err) {
+                    logger.error(`[Monero] There was an error while splitting the address ${address}: ${err}`);
+                    resolve(null);
+                    return;
+                }                
+                resolve({ paymentId: message.result.payment_id, address: message.result.standard_address });
+            });
+        })
+    }
+
+    /**
+     * When querying the Monero RPC wallet we get full decimals back instead of floats. Maybe because
+     * floats can be a hussle sometimes. Anyway, we have to convert them back into the original format.
+     */
+    private decimalToFloat(int: number) {
+        return int / 1000000000000;
+    }
+}

src/models/invoice/invoice.schema.ts

@@ -19,7 +19,7 @@ const schemaPaymentMethods = new Schema({
 }, { _id: false });
 
 const schemaInvoice = new Schema({
-    selector: { type: String, length: 128, required: true },
+    selector: { type: String, length: 32, required: true },
     paymentMethods: [{ type: schemaPaymentMethods, required: true }],
     paymentMethod: { type: String, enum: Object.values(CryptoUnits), required: false },
     receiveAddress: { type: String, required: false },