juna/src/blur/GhostApi.ts

A cross platform NFT lending client for serious lenders

import { PrivateKeyAccount, createWalletClient, WalletClient, http } from "viem";
import { mainnet } from "viem/chains";
import { privateKeyToAccount } from "viem/accounts";
import { BlurLoan, BlurOffer } from "./support/types";
import { LendingPlatform, Offer, OfferType } from "../types";
import { BETH } from "../support/currencies";
import { config } from "../config";
import { Axios } from "axios";

export class GhostApi {
  private axios: Axios;
  private client: WalletClient;
  private account: PrivateKeyAccount;

  constructor(
    privateKey: `0x${string}`,
    rpcUrl: `https://${string}` = config.defaultRpc,
    apiKey: string,
    walletAddress?: string,
  ) {
    this.account = privateKeyToAccount(privateKey);
    this.client = createWalletClient({
      account: this.account,
      chain: mainnet,
      transport: http(rpcUrl),
    });
    this.axios = new Axios({
      headers: {
        "x-api-key": apiKey,
        "x-wallet-address": walletAddress ?? this.account.address,
      },
    });
  }

  public async getLiens(address: `0x${string}`): Promise<BlurLoan[]> {
    const result = await this.axios.get(`${config.blur.baseUrlPortfolio}/${address.toLowerCase()}/liens`);
    return JSON.parse(result.data).liens;
  }

  public async getLoanOffers(accountAddress: `0x${string}`, collectionAddress?: `0x${string}`): Promise<BlurOffer[]> {
    const result = await this.axios.get(
      `${config.blur.baseUrlPortfolio}/${accountAddress.toLowerCase()}/loan-offers?contractAddress=${collectionAddress}`,
    );
    return JSON.parse(result.data).loanOffers;
  }

  public async postLoanOffer(
    collectionAddress: `0x${string}`,
    principal: number,
    limit: number,
    apr: number,
    expiryInMinutes: number,
  ): Promise<Offer> {
    // Format the query
    const payload = {
      contractAddress: collectionAddress.toLowerCase(),
      orders: [
        {
          contractAddress: collectionAddress.toLowerCase(),
          expirationTime: new Date(new Date().getTime() + expiryInMinutes * 60 * 1000).toISOString(),
          maxAmount: principal.toString(),
          rate: apr * 10000,
          totalAmount: limit.toString(),
        },
      ],
      userAddress: this.account.address.toLowerCase(),
    };
    const result = await this.axios.post(`${config.blur.baseUrlBlend}/loan-offer/format`, JSON.stringify(payload), {
      headers: { "Content-Type": "application/json" },
    });
    const format = JSON.parse(result.data);

    // Signing
    const signData = format.signatures[0].signData;
    signData.value.minAmount = BigInt(signData.value.minAmount.hex);
    signData.value.maxAmount = BigInt(signData.value.maxAmount.hex);
    signData.value.totalAmount = BigInt(signData.value.totalAmount.hex);
    signData.value.salt = BigInt(signData.value.salt.hex);
    signData.value.auctionDuration = BigInt(signData.value.auctionDuration.hex);
    signData.value.expirationTime = BigInt(signData.value.expirationTime.hex);

    const signature = await this.account.signTypedData({
      domain: signData.domain,
      types: signData.types,
      primaryType: "LoanOffer",
      message: signData.value,
    });

    // Submit the offer
    const payload2 = {
      contractAddress: collectionAddress.toLowerCase(),
      orders: [
        {
          contractAddress: collectionAddress.toLowerCase(),
          expirationTime: new Date(new Date().getTime() + expiryInMinutes * 60 * 1000).toISOString(),
          maxAmount: principal.toString(),
          rate: apr * 10000,
          totalAmount: limit.toString(),
          signature: signature,
          marketplaceData: format.signatures[0].marketplaceData,
        },
      ],
      userAddress: this.account.address.toLowerCase(),
    };
    const result2 = await this.axios.post(`${config.blur.baseUrlBlend}/loan-offer/submit`, JSON.stringify(payload2), {
      headers: { "Content-Type": "application/json" },
    });
    const response = JSON.parse(result2.data);

    return {
      id: response.hashes[0],
      platform: LendingPlatform.blur,
      lender: this.account.address,
      offerDate: new Date(),
      expiryDate: new Date(new Date().getTime() + expiryInMinutes * 60 * 1000),
      type: OfferType.collectionOffer,
      currency: BETH,
      principal: principal,
      durationInDays: 0,
      apr: apr,
      collateral: {
        collectionAddress: collectionAddress,
        collectionName: "",
        nftId: "",
      },
    };
  }

  public async recallLoan(collectionAddress: `0x${string}`, loanId: string, nftId: string) {
    // Fetching the tx data
    const payload = {
      userAddress: this.account.address.toLowerCase(),
      contractAddress: collectionAddress.toLowerCase(),
      lienRequests: [
        {
          lienId: loanId,
          tokenId: nftId,
        },
      ],
    };
    const result = await this.axios.post(`${config.blur.baseUrlBlend}/loan-offer/end`, JSON.stringify(payload), {
      headers: { "Content-Type": "application/json" },
    });
    const format = JSON.parse(result.data);

    // Sending the transaction
    const tx = format.data.actions[0].txnData;
    await this.client.sendTransaction(tx);
  }
}