Modify PRE operator schema's entity

- Entity name changed to PREOperator, which is more descriptive.
- Added OperatorBonded event handler, so PREOperator instance is
created when a new operator is bonded.
- Added confirmationTimestamp field, which will store the time in which
the operator is confirmed.
- Update getEpochStakeId function to accept epoch ID. If no argument
passed, the function takes the current epoch count.

schema.graphql

@@ -22,7 +22,7 @@ type StakeData @entity {
 type EpochStake @entity {
   # ID is the staking prov. add. + epoch counter
   id: ID!
-  stakingProvider: Bytes! # address
+  stakingProvider: Bytes!
   amount: BigInt!
 }
 
@@ -77,10 +77,11 @@ type TokenholderDelegation implements Delegation @entity {
   delegators: [Account!] @derivedFrom(field: "delegatee")
 }
 
-type ConfirmedOperator @entity {
+type PREOperator @entity {
+  # ID is the staking provider address
   id: ID!
-  stakingProvider: Bytes! # address
-  operator: Bytes! # address
+  operator: Bytes!
+  confirmationTimestamp: BigInt
 }
 
 type DAOMetric @entity {

src/mapping.ts

@@ -1,5 +1,8 @@
 import { crypto, ByteArray, BigInt, log } from "@graphprotocol/graph-ts"
-import { OperatorConfirmed } from "../generated/SimplePREApplication/SimplePREApplication"
+import {
+  OperatorBonded,
+  OperatorConfirmed,
+} from "../generated/SimplePREApplication/SimplePREApplication"
 import {
   Staked,
   ToppedUp,
@@ -13,9 +16,9 @@ import {
   StakeData,
   Epoch,
   EpochStake,
-  ConfirmedOperator,
   Account,
   MinStakeAmount,
+  PREOperator,
 } from "../generated/schema"
 import {
   getDaoMetric,
@@ -68,7 +71,7 @@ export function handleStaked(event: Staked): void {
   lastEpoch.save()
 
   const epochStakes = populateNewEpochStakes(lastEpoch.stakes)
-  const epochStakeId = getEpochStakeId(stakingProvider.toHexString())
+  const epochStakeId = getEpochStakeId(stakingProvider)
   const epochStake = new EpochStake(epochStakeId)
   epochStake.stakingProvider = stakingProvider
   epochStake.amount = stakeAmount
@@ -138,7 +141,7 @@ export function handleToppedUp(event: ToppedUp): void {
   lastEpoch.save()
 
   const epochStakes = populateNewEpochStakes(lastEpoch.stakes)
-  const epochStakeId = getEpochStakeId(stakingProvider.toHexString())
+  const epochStakeId = getEpochStakeId(stakingProvider)
   let epochStake = EpochStake.load(epochStakeId)
   if (!epochStake) {
     epochStake = new EpochStake(epochStakeId)
@@ -222,7 +225,7 @@ export function handleUnstaked(event: Unstaked): void {
   lastEpoch.save()
 
   const epochStakes = populateNewEpochStakes(lastEpoch.stakes)
-  const epochStakeId = getEpochStakeId(stakingProvider.toHexString())
+  const epochStakeId = getEpochStakeId(stakingProvider)
   const epochStake = EpochStake.load(epochStakeId)
   epochStake!.amount = epochStake!.amount.minus(amount)
   epochStake!.save()
@@ -272,16 +275,21 @@ export function handleDelegateVotesChanged(event: DelegateVotesChanged): void {
   daoMetric.save()
 }
 
+export function handleOperatorBonded(event: OperatorBonded): void {
+  const preOperator = new PREOperator(
+    event.params.stakingProvider.toHexString()
+  )
+  preOperator.operator = event.params.operator
+  preOperator.save()
+}
+
 export function handleOperatorConfirmed(event: OperatorConfirmed): void {
-  let operator = ConfirmedOperator.load(
+  const preOperator = new PREOperator(
     event.params.stakingProvider.toHexString()
   )
-  if (!operator) {
-    operator = new ConfirmedOperator(event.params.stakingProvider.toHexString())
-  }
-  operator.stakingProvider = event.params.stakingProvider
-  operator.operator = event.params.operator
-  operator.save()
+  preOperator.operator = event.params.operator
+  preOperator.confirmationTimestamp = event.block.timestamp
+  preOperator.save()
 }
 
 export function handleMinStakeAmountChanged(

src/utils/epochs.ts

@@ -1,12 +1,15 @@
-import { BigInt } from "@graphprotocol/graph-ts"
+import { Address, BigInt } from "@graphprotocol/graph-ts"
 import { Epoch, EpochStake, EpochCounter } from "../../generated/schema"
 
 const STAKING_CONTRACT_DEPLOY_TIMESTAMP = 1643633638
 const EPOCH_COUNTER_ID = "epoch-counter"
 
-export function getEpochStakeId(stakingProvider: string): string {
-  const epochCount = getEpochCount()
-  return `${stakingProvider}-${epochCount}`
+export function getEpochStakeId(
+  stakingProvider: Address,
+  epoch: i32 = -1
+): string {
+  const epochCount = epoch == -1 ? getEpochCount() : epoch
+  return `${stakingProvider.toHexString()}-${epochCount}`
 }
 
 export function getOrCreateLastEpoch(): Epoch {
@@ -27,7 +30,8 @@ export function getOrCreateLastEpoch(): Epoch {
 export function populateNewEpochStakes(stakes: string[]): string[] {
   for (let i = 0; i < stakes.length; i++) {
     const epochStake = EpochStake.load(stakes[i])
-    epochStake!.id = getEpochStakeId(epochStake!.stakingProvider.toHexString())
+    const stakingProvider = Address.fromBytes(epochStake!.stakingProvider)
+    epochStake!.id = getEpochStakeId(stakingProvider)
     epochStake!.save()
     stakes[i] = epochStake!.id
   }

subgraph.yaml

@@ -71,11 +71,13 @@ dataSources:
       apiVersion: 0.0.5
       language: wasm/assemblyscript
       entities:
-        - Operator
+        - PREOperator
       abis:
         - name: SimplePREApplication
           file: ./abis/SimplePREApplication.json
       eventHandlers:
         - event: OperatorConfirmed(indexed address,indexed address)
           handler: handleOperatorConfirmed
+        - event: OperatorBonded(indexed address,indexed address,uint256)
+          handler: handleOperatorBonded
       file: ./src/mapping.ts