nft-backed loans subgraph entities

schema.graphql

type Loan @entity {
  id: ID!
  closed: Boolean!
  perSecondInterestRate: BigInt!
  accumulatedInterest: BigInt!
  lastAccumulatedTimestamp: BigInt!
  durationSeconds: BigInt!
  loanAmount: BigInt!
  collateralTokenId: BigInt!
  collateralContractAddress: Bytes!
  loanAssetContractAddress: Bytes!
  # not in contract
  creator: Bytes!
  borrowTickerHolder: Bytes
  lendTicketHolder: Bytes
  createdAt: Int!
  loanAssetSymbol: String!
  loanAssetDecimal: Int!
  collateralAssetName: String!
  # event references
  lendEvents: [LendEvent!] @derivedFrom(field: "loan")
  buyoutEvents: [BuyoutEvent!] @derivedFrom(field: "loan")
  repaymentEvent: RepaymentEvent @derivedFrom(field: "loan")
  collateralSeizureEvent: CollateralSeizureEvent @derivedFrom(field: "loan")
}

type LendEvent @entity {
  id: ID!
  loan: Loan!
  lender: Bytes!
  loanAmount: BigInt!
  durationSeconds: BigInt!
  perSecondInterestRate: BigInt!
  timestamp: Int!
}

type BuyoutEvent @entity {
  id: ID!
  loan: Loan!
  newLender: Bytes!
  previousLender: Bytes!
  loanAmount: BigInt!
  interestEarned: BigInt!
  timestamp: Int!
}

type RepaymentEvent @entity {
  id: ID!
  loan: Loan!
  repayer: Bytes!
  paidTo: Bytes!
  loanAmount: BigInt!
  interestEarned: BigInt!
  timestamp: Int!
}

type CollateralSeizureEvent @entity {
  id: ID!
  loan: Loan!
  timestamp: Int!
}