Exchange tokens via mento broker

.changeset/empty-beans-sell.md

@@ -0,0 +1,5 @@
+---
+'@celo/celocli': major
+---
+
+Remove the deprecated exchange:gold command. exchange:celo is a drop in replacement

.changeset/light-humans-smell.md

@@ -0,0 +1,5 @@
+---
+'@celo/celocli': minor
+---
+
+Add support for swapping celo -- cStables via mento broker

packages/cli/package.json

@@ -23,7 +23,7 @@
   },
   "scripts": {
     "clean": "tsc -b . --clean",
-    "dev": "ts-node ./bin/dev.js",
+    "dev": "yarn build && ts-node ./bin/dev.js",
     "build": "tsc -b .",
     "docs": "./generate_docs.sh",
     "lint": "yarn run --top-level eslint -c .eslintrc.js ",
@@ -47,6 +47,7 @@
     "@celo/wallet-local": "^5.1.1",
     "@ethereumjs/util": "8.0.5",
     "@ledgerhq/hw-transport-node-hid": "^6.27.4",
+    "@mento-protocol/mento-sdk": "^0.2.2",
     "@oclif/core": "^3.18.1",
     "@oclif/plugin-autocomplete": "^3.0.5",
     "@oclif/plugin-commands": "^3.1.1",
@@ -60,6 +61,7 @@
     "chalk": "^2.4.2",
     "command-exists": "^1.2.9",
     "debug": "^4.1.1",
+    "ethers": "5",
     "fs-extra": "^8.1.0",
     "humanize-duration": "^3.29.0",
     "path": "^0.12.7",
@@ -130,7 +132,7 @@
         "description": "Participate in and view the state of Validator Elections"
       },
       "exchange": {
-        "description": "Exchange Celo Dollars and CELO via the stability mechanism"
+        "description": "Exchange Celo Dollars and CELO via Mento"
       },
       "governance": {
         "description": "Interact with on-chain governance proposals and hotfixes"

packages/cli/src/commands/exchange/celo.ts

@@ -1,21 +1,21 @@
 import { StableToken } from '@celo/contractkit'
 import { stableTokenInfos } from '@celo/contractkit/lib/celo-tokens'
-import { Flags } from '@oclif/core'
+import { Flags, ux } from '@oclif/core'
 import BigNumber from 'bignumber.js'
 import { BaseCommand } from '../../base'
 import { newCheckBuilder } from '../../utils/checks'
-import { displaySendTx, failWith } from '../../utils/cli'
+import { binaryPrompt, displaySendEthersTxViaCK, displaySendTx } from '../../utils/cli'
 import { CustomFlags } from '../../utils/command'
 import { checkNotDangerousExchange } from '../../utils/exchange'
 import { enumEntriesDupWithLowercase } from '../../utils/helpers'
+import { getMentoBroker } from '../../utils/mento-broker-adaptor'
 
-const largeOrderPercentage = 1
-const deppegedPricePercentage = 20
+const depeggedPricePercentage = 20
 
 const stableTokenOptions = enumEntriesDupWithLowercase(Object.entries(StableToken))
 export default class ExchangeCelo extends BaseCommand {
   static description =
-    'Exchange CELO for StableTokens via the stability mechanism. (Note: this is the equivalent of the old exchange:gold)'
+    'Exchange CELO for StableTokens via Mento. (Note: this is the equivalent of the old exchange:gold)'
 
   static flags = {
     ...BaseCommand.flags,
@@ -49,40 +49,68 @@ export default class ExchangeCelo extends BaseCommand {
     const minBuyAmount = res.flags.forAtLeast
     const stableToken = stableTokenOptions[res.flags.stableToken]
 
-    let exchange
-    try {
-      exchange = await kit.contracts.getExchange(stableToken)
-    } catch {
-      failWith(`The ${stableToken} token was not deployed yet`)
-    }
-
     await newCheckBuilder(this).hasEnoughCelo(res.flags.from, sellAmount).runChecks()
 
+    const [celoToken, stableTokenAddress, { mento, brokerAddress }] = await Promise.all([
+      kit.contracts.getGoldToken(),
+      kit.registry.addressFor(stableTokenInfos[stableToken].contract),
+      getMentoBroker(kit.connection),
+    ])
+
+    async function getQuote(tokenIn: string, tokenOut: string, amount: string) {
+      const quoteAmountOut = await mento.getAmountOut(tokenIn, tokenOut, amount)
+      const expectedAmountOut = quoteAmountOut.mul(99).div(100)
+      return expectedAmountOut
+    }
+
+    ux.action.start(`Fetching Quote`)
+    const expectedAmountToReceive = await getQuote(
+      celoToken.address,
+      stableTokenAddress,
+      sellAmount.toFixed()
+    )
+    ux.action.stop()
     if (minBuyAmount.toNumber() === 0) {
       const check = await checkNotDangerousExchange(
         kit,
         sellAmount,
-        largeOrderPercentage,
-        deppegedPricePercentage,
-        true,
+        new BigNumber(expectedAmountToReceive.toString()),
+        depeggedPricePercentage,
         stableTokenInfos[stableToken]
       )
-
       if (!check) {
-        console.log('Cancelled')
-        return
+        ux.info('Cancelled')
+        ux.exit(0)
+      }
+    } else if (expectedAmountToReceive.lt(minBuyAmount.toString())) {
+      const check = await binaryPrompt(
+        'Warning: the expected amount to receive is less than the minimum amount to receive. Are you sure you want to continue?',
+        false
+      )
+      if (!check) {
+        ux.info('Cancelled')
+        ux.exit(0)
       }
     }
 
-    const celoToken = await kit.contracts.getGoldToken()
-
     await displaySendTx(
       'increaseAllowance',
-      celoToken.increaseAllowance(exchange.address, sellAmount.toFixed())
+      celoToken.increaseAllowance(brokerAddress, sellAmount.toFixed())
     )
 
-    const exchangeTx = exchange.exchange(sellAmount.toFixed(), minBuyAmount!.toFixed(), true)
-    // Set explicit gas based on github.com/celo-org/celo-monorepo/issues/2541
-    await displaySendTx('exchange', exchangeTx, { gas: 300000 })
+    ux.log(
+      'Swapping',
+      sellAmount.toFixed(),
+      'CELO for at least',
+      expectedAmountToReceive.toString(),
+      stableToken
+    )
+    const tx = await mento.swapIn(
+      celoToken.address,
+      stableTokenAddress,
+      sellAmount.toFixed(),
+      expectedAmountToReceive
+    )
+    await displaySendEthersTxViaCK('exchange', tx, kit.connection)
   }
 }

packages/cli/src/commands/exchange/dollars.ts

@@ -2,7 +2,7 @@ import { StableToken } from '@celo/contractkit'
 import ExchangeStableBase from '../../exchange-stable-base'
 import { CustomFlags } from '../../utils/command'
 export default class ExchangeDollars extends ExchangeStableBase {
-  static description = 'Exchange Celo Dollars for CELO via the stability mechanism'
+  static description = 'Exchange Celo Dollars for CELO via Mento'
 
   static flags = {
     ...ExchangeStableBase.flags,

packages/cli/src/commands/exchange/euros.ts

@@ -2,7 +2,7 @@ import { StableToken } from '@celo/contractkit'
 import ExchangeStableBase from '../../exchange-stable-base'
 import { CustomFlags } from '../../utils/command'
 export default class ExchangeEuros extends ExchangeStableBase {
-  static description = 'Exchange Celo Euros for CELO via the stability mechanism'
+  static description = 'Exchange Celo Euros for CELO via Mento'
 
   static flags = {
     ...ExchangeStableBase.flags,

packages/cli/src/commands/exchange/reals.ts

@@ -2,7 +2,7 @@ import { StableToken } from '@celo/contractkit'
 import ExchangeStableBase from '../../exchange-stable-base'
 import { CustomFlags } from '../../utils/command'
 export default class ExchangeEuros extends ExchangeStableBase {
-  static description = 'Exchange Celo Brazilian Real (cREAL) for CELO via the stability mechanism'
+  static description = 'Exchange Celo Brazilian Real (cREAL) for CELO via Mento'
 
   static flags = {
     ...ExchangeStableBase.flags,

packages/cli/src/commands/exchange/show.ts

@@ -1,7 +1,7 @@
-import { StableTokenInfo } from '@celo/contractkit/lib/celo-tokens'
 import { Flags, ux } from '@oclif/core'
 
 import { BaseCommand } from '../../base'
+import { getExchangeRates } from '../../utils/mento-broker-adaptor'
 
 export default class ExchangeShow extends BaseCommand {
   static description = 'Show the current exchange rates offered by the Exchange'
@@ -23,21 +23,16 @@ export default class ExchangeShow extends BaseCommand {
     const { flags: parsedFlags } = await this.parse(ExchangeShow)
 
     ux.action.start('Fetching exchange rates...')
-    const exchangeAmounts = await kit.celoTokens.forStableCeloToken(
-      async (info: StableTokenInfo) => {
-        const exchange = await kit.contracts.getContract(info.exchangeContract)
-        return {
-          buy: await exchange.getBuyTokenAmount(parsedFlags.amount as string, true),
-          sell: await exchange.getBuyTokenAmount(parsedFlags.amount as string, false),
-        }
-      }
-    )
+    const exchangeAmounts = await getExchangeRates(kit.connection, parsedFlags.amount as string)
     ux.action.stop()
 
-    Object.entries(exchangeAmounts).forEach((element) => {
-      this.log(`CELO/${element[0]}:`)
-      this.log(`${parsedFlags.amount} CELO => ${element[1]!.buy} ${element[0]}`)
-      this.log(`${parsedFlags.amount} ${element[0]} => ${element[1]!.sell} CELO`)
-    })
+    exchangeAmounts
+      .filter((element) => element !== undefined)
+      .forEach((element) => {
+        this.log(`CELO/${element?.symbol}:`)
+        this.log(`${parsedFlags.amount} CELO => ${element?.buy} ${element?.symbol}`)
+        this.log(`${parsedFlags.amount} ${element?.symbol} => ${element?.sell} CELO`)
+      })
+    ux.exit(0)
   }
 }

packages/cli/src/commands/exchange/stable.ts

@@ -5,7 +5,7 @@ import { enumEntriesDupWithLowercase } from '../../utils/helpers'
 
 const stableTokenOptions = enumEntriesDupWithLowercase(Object.entries(StableToken))
 export default class ExchangeStable extends ExchangeStableBase {
-  static description = 'Exchange Stable Token for CELO via the stability mechanism'
+  static description = 'Exchange Stable Token for CELO via Mento'
 
   static flags = {
     ...ExchangeStableBase.flags,

packages/cli/src/exchange-stable-base.ts

@@ -1,14 +1,14 @@
-import { StableToken } from '@celo/contractkit'
+import { CeloContract, StableToken } from '@celo/contractkit'
 import { stableTokenInfos } from '@celo/contractkit/lib/celo-tokens'
+import { ux } from '@oclif/core'
 import BigNumber from 'bignumber.js'
 import { BaseCommand } from './base'
 import { newCheckBuilder } from './utils/checks'
-import { displaySendTx, failWith } from './utils/cli'
+import { binaryPrompt, displaySendEthersTxViaCK, displaySendTx } from './utils/cli'
 import { CustomFlags } from './utils/command'
 import { checkNotDangerousExchange } from './utils/exchange'
-
-const largeOrderPercentage = 1
-const deppegedPricePercentage = 20
+import { getMentoBroker } from './utils/mento-broker-adaptor'
+const depeggedPricePercentage = 20
 export default class ExchangeStableBase extends BaseCommand {
   static flags = {
     ...BaseCommand.flags,
@@ -31,8 +31,8 @@ export default class ExchangeStableBase extends BaseCommand {
   async run() {
     const kit = await this.getKit()
     const res = await this.parse()
-    const sellAmount = res.flags.value
-    const minBuyAmount = res.flags.forAtLeast
+    const sellAmount = res.flags.value as BigNumber
+    const minBuyAmount = res.flags.forAtLeast as BigNumber
 
     if (!this._stableCurrency) {
       throw new Error('Stable currency not set')
@@ -41,38 +41,72 @@ export default class ExchangeStableBase extends BaseCommand {
       .hasEnoughStable(res.flags.from, sellAmount, this._stableCurrency)
       .runChecks()
 
-    let stableToken
-    let exchange
-    try {
-      stableToken = await kit.contracts.getStableToken(this._stableCurrency)
-      exchange = await kit.contracts.getExchange(this._stableCurrency)
-    } catch {
-      failWith(`The ${this._stableCurrency} token was not deployed yet`)
+    const [stableToken, celoNativeTokenAddress, { mento, brokerAddress }] = await Promise.all([
+      kit.contracts.getStableToken(this._stableCurrency),
+      kit.registry.addressFor(CeloContract.GoldToken),
+      getMentoBroker(kit.connection),
+    ])
+
+    ux.debug(`Prepare to exchange ${stableToken.address} for ${celoNativeTokenAddress}`)
+
+    // note using getAmountIn here to match way rate is shown in the oracles
+    async function getQuote(tokenIn: string, tokenOut: string, amount: string) {
+      const quoteAmountOut = await mento.getAmountIn(tokenIn, tokenOut, amount)
+      const expectedAmountOut = quoteAmountOut.mul(99).div(100)
+      return expectedAmountOut
     }
 
+    ux.action.start(`Fetching Quote`)
+
+    const expectedAmountToReceive = await getQuote(
+      stableToken.address,
+      celoNativeTokenAddress,
+      sellAmount.toFixed()
+    )
+    ux.action.stop()
     if (minBuyAmount.toNumber() === 0) {
       const check = await checkNotDangerousExchange(
         kit,
         sellAmount,
-        largeOrderPercentage,
-        deppegedPricePercentage,
-        false,
-        stableTokenInfos[this._stableCurrency]
+        new BigNumber(expectedAmountToReceive.toString()),
+        depeggedPricePercentage,
+        stableTokenInfos[this._stableCurrency as StableToken]
       )
 
       if (!check) {
-        console.log('Cancelled')
-        return
+        ux.log('Cancelled')
+        ux.exit(0)
+      }
+    } else if (expectedAmountToReceive.lt(minBuyAmount.toString())) {
+      const check = await binaryPrompt(
+        'Warning: the expected amount to receive is less than the minimum amount to receive. Are you sure you want to continue?',
+        false
+      )
+      if (!check) {
+        ux.log('Cancelled')
+        ux.exit(0)
       }
     }
 
     await displaySendTx(
       'increaseAllowance',
-      stableToken.increaseAllowance(exchange.address, sellAmount.toFixed())
+      stableToken.increaseAllowance(brokerAddress, sellAmount.toFixed())
     )
 
-    const exchangeTx = exchange.exchange(sellAmount.toFixed(), minBuyAmount!.toFixed(), false)
-    // Set explicit gas based on github.com/celo-org/celo-monorepo/issues/2541
-    await displaySendTx('exchange', exchangeTx, { gas: 300000 })
+    ux.info(
+      'Swapping',
+      sellAmount.toFixed(),
+      this._stableCurrency,
+      ' for at least',
+      expectedAmountToReceive.toString(),
+      ' CELO'
+    )
+    const tx = await mento.swapIn(
+      stableToken.address,
+      celoNativeTokenAddress,
+      sellAmount.toFixed(),
+      expectedAmountToReceive
+    )
+    await displaySendEthersTxViaCK('exchange', tx, kit.connection)
   }
 }