adding in stored balances (#49)

* adding in offerings for stored balances

* show balances

* simplify stored balance

* adding in stored balances

* add readme on stored balance

README.md

@@ -148,6 +148,14 @@ a quote, place an order, and finally check for status.
 Each interaction happens in the context of an "Exchange" which is a record of
 the interaction between the customer and the PFI.
 
+This PFI has support for "stored balances", to try this out: 
+
+```bash
+npm run example-stored-balance
+```
+
+This uses the special "STORED_BALANCE" payin and payout offerings to add/remove/send funds from the PFI's stored balance.
+
 
 ## Implementing a PFI
 

db/migrations/20230910041108_create-offering-table.sql

@@ -2,8 +2,8 @@
 CREATE TABLE offering (
   id SERIAL PRIMARY KEY,
   offeringid VARCHAR(255) NOT NULL,
-  basecurrency CHAR(3) NOT NULL,
-  quotecurrency CHAR(3) NOT NULL,
+  basecurrency VARCHAR(255) NOT NULL,
+  quotecurrency VARCHAR(255) NOT NULL,
   offering JSON NOT NULL,
   CONSTRAINT offeringid_idx UNIQUE (offeringid)
 );

package.json

@@ -53,6 +53,7 @@
     "example-create-issuer": "npm run _debug -- dist/example/create-issuer.js",
     "example-issue-credential": "npm run _debug -- dist/example/issue-credential.js",
     "example-e2e-exchange": "npm run _debug -- dist/example/full-tbdex-exchange.js",
+    "example-stored-balance": "npm run _debug -- dist/example/full-stored-balances.js",
     "lint": "eslint . --ext .ts --max-warnings 0",
     "lint:fix": "eslint . --ext .ts --fix",
     "seed-offerings": "npm run _start -- dist/seed-offerings.js",

src/db/balances-repository.ts

@@ -0,0 +1,33 @@
+import type { BalancesApi, Quote } from '@tbdex/http-server'
+import { Balance } from '@tbdex/http-server'
+import { config } from '../config.js'
+
+let available = '1000'
+
+export class _BalancesRepository implements BalancesApi {
+  async getBalances({ requesterDid }): Promise<Balance[]> {
+    console.log('getBalances for:', requesterDid)
+    const bal = Balance.create({
+      data: {
+        currencyCode: 'USDC',
+        available: available,
+      },
+      metadata: {
+        from: config.pfiDid.uri,
+      }
+    })
+    return [bal]
+  }
+
+  withdraw(quote: Quote) {
+    // substract this from available
+    available = (parseFloat(available) - parseFloat(quote.data.payout.amount)).toString()
+  }
+
+  deposit(quote: Quote) {
+    // add this to available
+    available = (parseFloat(available) + parseFloat(quote.data.payin.amount)).toString()
+  }
+}
+
+export const BalancesRepository = new _BalancesRepository()

src/db/exchange-repository.ts

@@ -1,7 +1,9 @@
-import { Message, Close, Order, OrderStatus, Quote, ExchangesApi, Rfq, Parser, Exchange } from '@tbdex/http-server'
+import { Message, Close, Order, OrderStatus, Quote, ExchangesApi, Rfq, Parser, Exchange, Offering } from '@tbdex/http-server'
 import type { MessageModel, MessageKind, GetExchangesFilter } from '@tbdex/http-server'
+import { OfferingRepository } from './offering-repository.js'
 import { Postgres } from './postgres.js'
 import { config } from '../config.js'
+import { BalancesRepository } from './balances-repository.js'
 
 class _ExchangeRepository implements ExchangesApi {
 
@@ -77,6 +79,8 @@ class _ExchangeRepository implements ExchangesApi {
     return await this.getMessage({ exchangeId: opts.exchangeId, messageKind: 'rfq' }) as Rfq
   }
 
+
+
   async getQuote(opts: { exchangeId: string }): Promise<Quote> {
     return await this.getMessage({ exchangeId: opts.exchangeId, messageKind: 'quote' }) as Quote
   }
@@ -123,6 +127,7 @@ class _ExchangeRepository implements ExchangesApi {
     }
   }
 
+
   async addMessage(opts: { message: Message }) {
     const { message } = opts
     const subject = aliceMessageKinds.has(message.kind) ? message.from : message.to
@@ -140,25 +145,17 @@ class _ExchangeRepository implements ExchangesApi {
     console.log(`Add ${message.kind} Result: ${JSON.stringify(result, null, 2)}`)
 
     if (message.kind == 'rfq') {
-      const quote = Quote.create({
-        metadata: {
-          from: config.pfiDid.uri,
-          to: message.from,
-          exchangeId: message.exchangeId
-        },
-        data: {
-          expiresAt: new Date(new Date().getTime() + 60 * 60000).toISOString(),
-          payin: {
-            currencyCode: 'BTC',
-            amount: '1000.00'
-          },
-          payout: {
-            currencyCode: 'KES',
-            amount: '123456789.00'
-          }
-        }
-      })
-      await quote.sign(config.pfiDid)
+      const rfq = message as Rfq
+      let quote: Quote
+      if (rfq.data.payin.kind == 'STORED_BALANCE' && rfq.data.payout.kind == 'WIRE_TRANSFER') {
+        quote = await this.withdrawalQuote(rfq)
+      }
+      if (rfq.data.payin.kind == 'WIRE_TRANSFER' && rfq.data.payout.kind == 'STORED_BALANCE') {
+        quote = await this.depositQuote(rfq)
+      }
+      else {
+        quote = await this.BtcKesQuote(rfq)
+      }
       this.addMessage({ message: quote as Quote})
     }
 
@@ -176,6 +173,13 @@ class _ExchangeRepository implements ExchangesApi {
       await orderStatus.sign(config.pfiDid)
       this.addMessage({ message: orderStatus as OrderStatus})
 
+      const quote = await this.getQuote({ exchangeId: message.exchangeId })
+      if (quote.data.payout.currencyCode == 'STORED_BALANCE') {
+        BalancesRepository.deposit(quote)
+      } else if (quote.data.payin.currencyCode == 'STORED_BALANCE') {
+        BalancesRepository.withdraw(quote)
+      }
+
       await new Promise(resolve => setTimeout(resolve, 1000)) // 1 second delay
 
       orderStatus = OrderStatus.create({
@@ -207,6 +211,77 @@ class _ExchangeRepository implements ExchangesApi {
       this.addMessage({ message: close as Close })
     }
   }
+
+
+  private async depositQuote(rfq: Rfq) {
+    const quote = Quote.create({
+      metadata: {
+        from: config.pfiDid.uri,
+        to: rfq.from,
+        exchangeId: rfq.exchangeId
+      },
+      data: {
+        expiresAt: new Date(new Date().getTime() + 60 * 60000).toISOString(),
+        payin: {
+          currencyCode: 'WIRE_TRANSFER',
+          amount: rfq.data.payin.amount
+        },
+        payout: {
+          currencyCode: 'STORED_BALANCE',
+          amount: rfq.data.payin.amount
+        }
+      }
+    })
+    await quote.sign(config.pfiDid)
+    return quote
+
+  }
+
+  private async withdrawalQuote(rfq: Rfq) {
+    const quote = Quote.create({
+      metadata: {
+        from: config.pfiDid.uri,
+        to: rfq.from,
+        exchangeId: rfq.exchangeId
+      },
+      data: {
+        expiresAt: new Date(new Date().getTime() + 60 * 60000).toISOString(),
+        payin: {
+          currencyCode: 'STORED_BALANCE',
+          amount: rfq.data.payin.amount
+        },
+        payout: {
+          currencyCode: 'WIRE_TRANSFER',
+          amount: rfq.data.payin.amount
+        }
+      }
+    })
+    await quote.sign(config.pfiDid)
+    return quote
+  }
+
+  private async BtcKesQuote(rfq: Rfq) {
+    const quote = Quote.create({
+      metadata: {
+        from: config.pfiDid.uri,
+        to: rfq.from,
+        exchangeId: rfq.exchangeId
+      },
+      data: {
+        expiresAt: new Date(new Date().getTime() + 60 * 60000).toISOString(),
+        payin: {
+          currencyCode: 'BTC',
+          amount: '1000.00'
+        },
+        payout: {
+          currencyCode: 'KES',
+          amount: '123456789.00'
+        }
+      }
+    })
+    await quote.sign(config.pfiDid)
+    return quote
+  }
 }
 
 const aliceMessageKinds = new Set(['rfq', 'order'])

src/db/index.ts

@@ -1,3 +1,4 @@
 export * from './offering-repository.js'
 export * from './exchange-repository.js'
+export * from './balances-repository.js'
 export * from './postgres.js'

src/example/full-stored-balances.ts

@@ -0,0 +1,140 @@
+import {
+  TbdexHttpClient,
+  Rfq,
+  Quote,
+  Order,
+  OrderStatus,
+  Close,
+} from '@tbdex/http-client'
+import { createOrLoadDid } from './utils.js'
+import { BearerDid } from '@web5/dids'
+import fs from 'fs'
+
+
+// load pfiDid from pfiDid.txt
+const pfiDid = fs.readFileSync('pfiDid.txt', 'utf-8').trim()
+
+
+const signedCredential = fs.readFileSync('signedCredential.txt', 'utf-8').trim()
+
+//
+//  Connect to the PFI and get the list of offerings (offerings are resources - anyone can ask for them)
+//
+const offerings = await TbdexHttpClient.getOfferings({ pfiDid: pfiDid })
+console.log('got offerings:', JSON.stringify(offerings, null, 2))
+
+
+//
+// Load alice's private key to sign RFQ
+//
+const alice = await createOrLoadDid('alice.json')
+
+const [balances] = await TbdexHttpClient.getBalances({ pfiDid: pfiDid, did: alice })
+console.log('got balances:', JSON.stringify(balances, null, 2))
+
+// lets make a deposit
+let offering = offerings[1]
+console.log('deposit offering', offering)
+const rfq = Rfq.create({
+  metadata: { from: alice.uri, to: pfiDid },
+  data: {
+    offeringId: offerings[1].id,
+    payin: {
+      kind: 'WIRE_TRANSFER',
+      amount: '100.00',
+      paymentDetails: {},
+    },
+    payout: {
+      kind: 'STORED_BALANCE',
+      paymentDetails: {},
+    },
+    claims: [], // no claims for now - will add in kcc soon
+  },
+})
+
+await rfq.sign(alice)
+
+try {
+  await TbdexHttpClient.createExchange(rfq)
+} catch (error) {
+  console.log('Can\'t create:', error)
+}
+console.log('sent RFQ: ', JSON.stringify(rfq, null, 2))
+
+let quote
+
+//Wait for Quote message to appear in the exchange
+while (!quote) {
+  const exchange = await TbdexHttpClient.getExchange({
+    pfiDid: pfiDid,
+    did: alice,
+    exchangeId: rfq.exchangeId
+  })
+
+  quote = exchange.find(msg => msg instanceof Quote)
+
+  if (!quote) {
+    // Wait 2 seconds before making another request
+    await new Promise(resolve => setTimeout(resolve, 2000))
+  }
+}
+
+//
+//
+// All interaction with the PFI happens in the context of an exchange.
+// This is where for example a quote would show up in result to an RFQ:
+const exchange = await TbdexHttpClient.getExchange({
+  pfiDid: pfiDid,
+  did: alice,
+  exchangeId: rfq.exchangeId
+})
+
+console.log('got exchange:', JSON.stringify(exchange, null, 2))
+
+// Place an order against that quote:
+const order = Order.create({
+  metadata: {
+    from: alice.uri,
+    to: pfiDid,
+    exchangeId: quote.exchangeId
+  },
+})
+await order.sign(alice)
+await TbdexHttpClient.submitOrder(order)
+console.log('Sent order: ', JSON.stringify(order, null, 2))
+
+await pollForStatus(order, pfiDid, alice)
+
+
+
+/*
+   * This is a very simple polling function that will poll for the status of an order.
+   */
+async function pollForStatus(order: Order, pfiDid: string, did: BearerDid) {
+  let close: Close
+  while (!close) {
+    const exchange = await TbdexHttpClient.getExchange({
+      pfiDid: pfiDid,
+      did: did,
+      exchangeId: order.exchangeId
+    })
+
+    for (const message of exchange) {
+      if (message instanceof OrderStatus) {
+        console.log('we got a new order status')
+        const orderStatus = message as OrderStatus
+        console.log('orderStatus', JSON.stringify(orderStatus, null, 2))
+      } else if (message instanceof Close) {
+        console.log('we have a close message')
+        close = message as Close
+        console.log('close', JSON.stringify(close, null, 2))
+        return close
+      }
+    }
+  }
+}
+
+const [end_balances] = await TbdexHttpClient.getBalances({ pfiDid: pfiDid, did: alice })
+console.log('starting balances:', JSON.stringify(balances, null, 2))
+console.log('end balances:', JSON.stringify(end_balances, null, 2))
+

src/example/full-tbdex-exchange.ts

@@ -23,11 +23,14 @@ const signedCredential = fs.readFileSync('signedCredential.txt', 'utf-8').trim()
 const [offering] = await TbdexHttpClient.getOfferings({ pfiDid: pfiDid })
 console.log('got offering:', JSON.stringify(offering, null, 2))
 
+
 //
 // Load alice's private key to sign RFQ
 //
 const alice = await createOrLoadDid('alice.json')
 
+const [balances] = await TbdexHttpClient.getBalances({ pfiDid: pfiDid, did: alice })
+console.log('got balances:', JSON.stringify(balances, null, 2))
 //
 // And here we go with tbdex-protocol!
 //