Historical Events

import { type Address } from 'viem';
import { base } from 'viem/chains';
import { getFeeBps } from '@/utils/contract';

import { CONTRACT_ADDRESS } from '@/utils/constants';

const API_URL = 'https://basescan.org';
const API_KEY = process.env.BASESCAN_API_KEY as string;

const PURCHASE_TICKET_TOPIC = "0xd72c70202ab87b3549553b1d4ceb2a632c83cb96fa2dfe65c30282862fe11ade";
const JACKPOT_RUN_TOPIC = "0x3208da215cdfa0c44cf3d81565b27f57d4c505bf1a48e40957e53aaf3ba2aa82";

const FEEBPS = await getFeeBps();

// fetch ticket purchases for all users
type TicketPurchaseInfo = { blockNumber: number; ticketsPurchased: number };
const fetchTicketPurchases = async (token: string) => {
  const batchSize = 500; // Maximum allowed by the API
  let allEvents: any[] = [];
  let page = 1;
  let hasMoreEvents = true;

  while (hasMoreEvents) {
    const urlParams = new URLSearchParams({
      module: 'logs',
      action: 'getLogs',
      address: CONTRACT_ADDRESS,
      topic0: PURCHASE_TICKET_TOPIC,
      apikey: API_KEY,
      page: page.toString(),
      offset: batchSize.toString(),
    });

    const request = `${API_URL}?${urlParams}`;
    const response = await fetch(request);
    const body = await response?.json();

    const request = `${API_URL}?${urlParams}`;
    const response = await fetch(request);
    const body = await response?.json();

    if (body.status === '1' && body.result && body.result.length > 0) {
      allEvents = allEvents.concat(body.result);
      if (body.result.length < batchSize) {
        hasMoreEvents = false;
      } else {
        page++;
        // Add a small delay to avoid rate limiting
        await new Promise((resolve) => setTimeout(resolve, 200));
      }
    } else {
      hasMoreEvents = false;
    }
  }

  const ticketPurchases = new Map<string, TicketPurchaseInfo[]>();
  allEvents.forEach((event: any) => {
    const userAddress = `0x${event.topics[1].substring(26, 66)}`;
    let ticketsPurchased;
    // The tickets purchased is the first 32 bytes of the data
    ticketsPurchased =
      parseInt(event.data.substring(0, 66), 16) /
        10000 /
        ((100 - FEEBPS) / 100);
    // The referrer address is the next 32 bytes, if you need to use it
    const referrerAddress = `0x${event.data.substring(66, 130)}`;
    const blockNumber = parseInt(event.blockNumber, 16);
    if (!ticketPurchases.has(userAddress)) {
      ticketPurchases.set(userAddress, []);
    }
    ticketPurchases.get(userAddress)?.push({ blockNumber, ticketsPurchased });
  });

  return ticketPurchases;
};

// Add this function to get the current block number
const getCurrentBlockNumber = async () => {
  const urlParams = new URLSearchParams({
    module: 'block',
    action: 'getblocknobytime',
    timestamp: Math.floor(Date.now() / 1000).toString(),
    closest: 'before',
    apikey: API_KEY,
  });
  const request = `${API_URL}?${urlParams}`;
  const response = await fetch(request);
  const body = await response?.json();
  return parseInt(body.result);
};

// fetch jackpot info (winnerAddress, winAmount, ticketsPurchasedByWinner, blockNumber, transactionHash) for all jackpots
type JackpotInfo = {
  winnerAddress: string;
  winAmount: number;
  ticketsPurchasedByWinner: number;
  blockNumber: number;
  transactionHash: string;
  estimatedTimestamp: number;
};
const fetchJackpotInfo = async (token: string) => {
  const urlParams = new URLSearchParams({
    module: 'logs',
    action: 'getLogs',
    address: CONTRACT_ADDRESS,
    topic0: JACKPOT_RUN_TOPIC,
    apikey: API_KEY,
  });
  const request = `${API_URL}?${urlParams}`;
  const response = await fetch(request);
  const body = await response?.json();
  const events = body.result;
  const currentBlockNumber = await getCurrentBlockNumber();
  const currentTimestamp = Math.floor(Date.now() / 1000);

  const jackpotInfos: JackpotInfo[] = [];
  events.forEach((event: any) => {
    // field 1 [66:130]
    const winner = event.data.substring(66, 130);
    const winnerAddress =
      parseInt(winner, 16) === 0
        ? 'LP_WINNER'
        : `0x${winner.substring(24, 64)}`;
    // field 3 [194:258]
    const winAmount = parseInt(event.data.substring(194, 258), 16) / 10 ** 18;
    // field 4 [258:322]
    const ticketsPurchasedByWinner =
      parseInt(event.data.substring(258, 322), 16) /
      10000 /
      ((100 - FEEBPS) / 100);
    const blockNumber = parseInt(event.blockNumber, 16);
    const transactionHash = event.transactionHash;
    const estimatedTimestamp =
      currentTimestamp - (currentBlockNumber - blockNumber) * 2; // 2 seconds per block

    const jackpotInfo = {
      winnerAddress,
      winAmount,
      ticketsPurchasedByWinner,
      blockNumber,
      transactionHash,
      estimatedTimestamp,
    };
    jackpotInfos.push(jackpotInfo);
  });

  return jackpotInfos;
};

// build jackpot history for a user address by fetching jackpot info and merging with user's ticket purchase count
type UserJackpotInfo = {
  winnerAddress: string;
  winAmount: number;
  ticketsPurchasedByWinner: number;
  blockNumber: number;
  transactionHash: string;
  ticketsPurchasedByUser: number;
  estimatedTimestamp: number;
};
const buildUserJackpotHistory = async (
  userAddress: string | undefined,
  token: string
) => {
  const jackpotInfos = await fetchJackpotInfo(token);

  if (!userAddress) {
    return jackpotInfos.map((info) => ({
      ...info,
      ticketsPurchasedByUser: 0,
    }));
  }

  const ticketPurchases = await fetchTicketPurchases(token);
  const userTicketPurchases =
    ticketPurchases.get(userAddress.toLowerCase()) || [];
  const userJackpotHistory: UserJackpotInfo[] = [];
  let prevBlock = 0;
  jackpotInfos.forEach((jackpotInfo) => {
    let ticketsPurchasedByUser = 0;
    userTicketPurchases.forEach((userTicketPurchase) => {
      if (
        prevBlock <= userTicketPurchase.blockNumber &&
        userTicketPurchase.blockNumber < jackpotInfo.blockNumber
      ) {
        ticketsPurchasedByUser += userTicketPurchase.ticketsPurchased;
      }
    });
    prevBlock = jackpotInfo.blockNumber;
    userJackpotHistory.push({
      ...jackpotInfo,
      ticketsPurchasedByUser,
    });
  });

  return userJackpotHistory;
};

export { buildUserJackpotHistory, type UserJackpotInfo };