feat(subgraph): Receipts improved (#13824)

* adding comments

* using the GNP_CHANGED event to identify values in subgraphs

* undue change

* extracting the unlock address

* fixed wasm

* fixing API

* fixing mocks

* adding more comments

* add test case for GNPChanged

* better mock

* unit test ok

* use data field in receipt instead of topics

* Update subgraph/src/receipt.ts

* Update subgraph/tests/mockTxReceipt.ts

---------

Co-authored-by: Clément Renaud <clement@unlock-protocol.com>
Co-authored-by: Clément Renaud <clement+git@clementrenaud.com>

subgraph/src/receipt.ts

@@ -1,5 +1,10 @@
-import { BigInt, log, Bytes, ethereum } from '@graphprotocol/graph-ts'
-import { ERC20_TRANSFER_TOPIC0, nullAddress } from '../tests/constants'
+import { BigInt, log, Bytes, ethereum, Address } from '@graphprotocol/graph-ts'
+import {
+  GNP_CHANGED_TOPIC0,
+  ERC20_TRANSFER_TOPIC0,
+  nullAddress,
+} from '../tests/constants'
+import { PublicLockV11 as PublicLock } from '../generated/templates/PublicLock/PublicLockV11'
 
 import { Lock, Receipt } from '../generated/schema'
 
@@ -32,13 +37,14 @@ export function createReceipt(event: ethereum.Event): void {
     ? lock.tokenAddress
     : Bytes.fromHexString(nullAddress)
 
+  const txReceipt = event.receipt!
+  const logs: ethereum.Log[] = txReceipt.logs
+
   if (tokenAddress != Bytes.fromHexString(nullAddress)) {
     log.debug('Creating receipt for ERC20 lock {} {}', [
       lockAddress,
       tokenAddress.toHexString(),
     ])
-    const txReceipt = event.receipt!
-    const logs: ethereum.Log[] = txReceipt.logs
 
     if (logs) {
       // If it is an ERC20 lock, there should be multiple events
@@ -76,9 +82,36 @@ export function createReceipt(event: ethereum.Event): void {
       // which means we don't need to create a receipt.
     }
   } else {
-    log.debug('Creating receipt for base currency lock {}', [lockAddress])
+    log.debug('Creating receipt for native currency lock {}', [lockAddress])
     receipt.payer = event.transaction.from.toHexString()
     receipt.amountTransferred = event.transaction.value
+    // We cannot trust `event.transaction.value` because the purchase function could in fact
+    // be happening inside of a larger transaction whose value is not the amount transfered,
+    // In that case, we need to look up the GNPChanged event
+    // This is a very fragile setup and we should consider moving to a more formal event triggered
+    // by the contract, like a `Receipt` event that would include everything we need.
+    if (logs) {
+      const lockContract = PublicLock.bind(Address.fromString(lockAddress))
+      const unlockAddress = lockContract.try_unlockProtocol()
+      let value = BigInt.zero()
+      for (let i = 0; i < logs.length; i++) {
+        const txLog = logs[i]
+        if (
+          txLog.address == unlockAddress.value &&
+          txLog.topics[0].toHexString() == GNP_CHANGED_TOPIC0
+        ) {
+          const decoded = ethereum
+            .decode('(uint256,uint256,address,uint256,address)', txLog.data)!
+            .toTuple()
+
+          const keyValue = decoded[1].toBigInt()
+          value = value.plus(keyValue)
+        }
+      }
+      if (value > BigInt.zero()) {
+        receipt.amountTransferred = value
+      }
+    }
   }
 
   const totalGas = event.transaction.gasPrice.plus(event.transaction.gasLimit)

subgraph/tests/constants.ts

@@ -8,6 +8,9 @@ export const lockManagers = [
   '0x0000000000000000000000000000000000000125',
 ]
 
+// protocol
+export const unlockAddress = '0x0000000000000000000000000000000000000018'
+
 // key
 export const keyOwnerAddress = '0x0000000000000000000000000000000000000002'
 export const tokenId = 1234
@@ -32,11 +35,15 @@ export const symbol = 'METAKEY'
 export const baseTokenURI = 'https:/custom-lock.com/api/key/'
 
 // default address used in newMockEvent() function
-export const defaultMockAddress = '0xa16081f360e3847006db660bae1c6d1b2e17ec2a'
+export const defaultMockAddress =
+  '0xA16081F360e3847006dB660bae1c6d1b2e17eC2A'.toLowerCase()
 export const nullAddress = '0x0000000000000000000000000000000000000000'
 
 // TODO: compile from contract ABI
 // WARNING : For some tokens it may be different. In that case we would move to a list!
 // TODO: for easier handling on future locks: trigger an "paid" event with the amount and data needed?
 export const ERC20_TRANSFER_TOPIC0 =
   '0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef'
+
+export const GNP_CHANGED_TOPIC0 =
+  '0x3b50eb9d9b4a8db204f2928c9e572c2865b0d02803493ccb6aa256848323ebb7'

subgraph/tests/keys-utils.ts

@@ -23,6 +23,7 @@ import {
   Transfer,
   RenewKeyPurchase,
 } from '../generated/templates/PublicLock/PublicLock'
+import { GNPChanged } from '../generated/Unlock/Unlock'
 
 import {
   now,
@@ -31,8 +32,9 @@ import {
   tokenId,
   keyOwnerAddress,
   lockOwner,
+  nullAddress,
 } from './constants'
-import { newTransactionReceipt } from './createCancelKeyEvent'
+import { newCancelKeyTransactionReceipt } from './mockTxReceipt'
 
 export function mockDataSourceV8(): void {
   const v8context = new DataSourceContext()
@@ -204,7 +206,7 @@ export function createCancelKeyEvent(
 ): CancelKey {
   const cancelKeyEvent = changetype<CancelKey>(newMockEvent())
 
-  cancelKeyEvent.receipt = newTransactionReceipt(tokenAddress, refund)
+  cancelKeyEvent.receipt = newCancelKeyTransactionReceipt(tokenAddress, refund)
   cancelKeyEvent.address = dataSource.address()
 
   cancelKeyEvent.parameters = []