From ae7b3e5612b5a99870ee0ae6d17b36732d6c3292 Mon Sep 17 00:00:00 2001
From: Mark Tan <marktanrj@gmail.com>
Date: Thu, 1 Dec 2022 10:42:23 +0800
Subject: [PATCH] Extend createDeFiTx

---
 .../__tests__/txn/txn_builder_p2wpkh.test.ts  | 46 ++++++++++++++++++-
 .../src/txn/txn_builder.ts                    | 16 +++++--
 2 files changed, 56 insertions(+), 6 deletions(-)

diff --git a/packages/jellyfish-transaction-builder/__tests__/txn/txn_builder_p2wpkh.test.ts b/packages/jellyfish-transaction-builder/__tests__/txn/txn_builder_p2wpkh.test.ts
index 6e0740cad4..e6d8da354a 100644
--- a/packages/jellyfish-transaction-builder/__tests__/txn/txn_builder_p2wpkh.test.ts
+++ b/packages/jellyfish-transaction-builder/__tests__/txn/txn_builder_p2wpkh.test.ts
@@ -1,9 +1,9 @@
 import BigNumber from 'bignumber.js'
 import { MasterNodeRegTestContainer } from '@defichain/testcontainers'
 import { getProviders, MockProviders } from '../provider.mock'
-import { P2WPKHTxnBuilder } from '../../src'
+import { P2WPKHTxnBuilder, Prevout } from '../../src'
 import { fundEllipticPair } from '../test.utils'
-import { CDfTx, DeFiOpUnmapped, OP_CODES, OP_DEFI_TX } from '@defichain/jellyfish-transaction'
+import { CDfTx, DeFiOpUnmapped, OP_CODES, OP_DEFI_TX, Vin, Vout } from '@defichain/jellyfish-transaction'
 import { RegTest } from '@defichain/jellyfish-network'
 
 // P2WPKHTxnBuilder is abstract and not instantiable
@@ -92,4 +92,46 @@ describe('createDeFiTx()', () => {
     expect(result.vout[1].value.gt(new BigNumber(99.999).minus(spendAmount))).toBeTruthy()
     expect(result.vout[1].value.lt(new BigNumber(100).minus(spendAmount))).toBeTruthy()
   })
+
+  it('should create DfTx stack correctly with custom vin and vout', async () => {
+    const script = await providers.elliptic.script()
+
+    const collateralPrevout: Prevout = {
+      txid: '1111111122222222333333334444444455555555666666667777777788888888',
+      vout: 0,
+      script: script,
+      value: new BigNumber(15),
+      tokenId: 0
+    }
+    const collateralVout: Vout = {
+      script: script,
+      value: new BigNumber(15),
+      tokenId: 0
+    }
+    const collateralVin: Vin = {
+      txid: '1111111122222222333333334444444455555555666666667777777788888888',
+      index: 1,
+      script: { stack: [] },
+      sequence: 0xffffffff
+    }
+    const customVinVout = {
+      prevout: collateralPrevout,
+      vin: collateralVin,
+      vout: collateralVout
+    }
+
+    const result = await builder.createDeFiTx(dummyDfTx, script, undefined, [customVinVout])
+
+    expect(result.vin.length).toStrictEqual(8)
+    expect(result.vout.length).toStrictEqual(3)
+
+    expect(result.vout[0].value).toStrictEqual(new BigNumber(0))
+    expect(result.vout[1]).toStrictEqual(expect.objectContaining({
+      value: new BigNumber(15),
+      script: script
+    }))
+    expect(result.vout[2].value.gt(99.999)).toBeTruthy()
+    expect(result.vout[2].value.lt(100)).toBeTruthy()
+    expect(result.vout[2].script).toStrictEqual(script)
+  })
 })
diff --git a/packages/jellyfish-transaction-builder/src/txn/txn_builder.ts b/packages/jellyfish-transaction-builder/src/txn/txn_builder.ts
index 90300bb787..3289e2e397 100644
--- a/packages/jellyfish-transaction-builder/src/txn/txn_builder.ts
+++ b/packages/jellyfish-transaction-builder/src/txn/txn_builder.ts
@@ -89,6 +89,8 @@ export abstract class P2WPKHTxnBuilder {
    * Craft a transaction with OP_DEFI_TX from the output of OP_CODES.OP_DEFI_TX_.
    * This is a helper method for creating custom defi transactions.
    *
+   * Optionally, allow for custom inputs with vin and vout.
+   *
    * As DeFi custom transaction will always require small amount of DFI,
    * collectPrevouts() is set to search for at least 0.001 DFI amount of prevout.
    * This will also evidently merge small prevout during the operation.
@@ -98,15 +100,21 @@ export abstract class P2WPKHTxnBuilder {
    * @param {OP_DEFI_TX} opDeFiTx to create
    * @param {Script} changeScript to send unspent to after deducting the fees
    * @param {BigNumber} [outValue=0] for the opDeFiTx, usually always be 0.
+   * @param {Array<{ vin: Vin, vout: Vout, prevout: Prevout }>} [customVinVout = []] for custom vin and vout
    */
   async createDeFiTx (
     opDeFiTx: OP_DEFI_TX,
     changeScript: Script,
-    outValue: BigNumber = new BigNumber('0')
+    outValue: BigNumber = new BigNumber('0'),
+    customVinVout: Array<{ vin: Vin, vout: Vout, prevout: Prevout }> = []
   ): Promise<TransactionSegWit> {
     const minFee = outValue.plus(0.001) // see JSDoc above
     const { prevouts, vin, total } = await this.collectPrevouts(minFee)
 
+    const customVins = customVinVout.map(({ vin }) => vin)
+    const customPrevouts = customVinVout.map(({ prevout }) => prevout)
+    const customVouts = customVinVout.map(({ vout }) => vout)
+
     const deFiOut: Vout = {
       value: outValue,
       script: {
@@ -123,15 +131,15 @@ export abstract class P2WPKHTxnBuilder {
 
     const txn: Transaction = {
       version: DeFiTransactionConstants.Version,
-      vin: vin,
-      vout: [deFiOut, change],
+      vin: [...vin, ...customVins],
+      vout: [deFiOut, ...customVouts, change],
       lockTime: 0x00000000
     }
 
     const fee = await this.calculateFee(txn)
     change.value = total.minus(outValue).minus(fee)
 
-    return await this.sign(txn, prevouts)
+    return await this.sign(txn, [...prevouts, ...customPrevouts])
   }
 
   /**