mempool/backend/src/api/liquid/elements-parser.ts

import { IBitcoinApi } from '../bitcoin/bitcoin-api.interface';
import bitcoinClient from '../bitcoin/bitcoin-client';
import bitcoinSecondClient from '../bitcoin/bitcoin-second-client';
import { Common } from '../common';
import { DB } from '../../database';
import logger from '../../logger';

class ElementsParser {
  private isRunning = false;

  constructor() { }

  public async $parse() {
    if (this.isRunning) {
      return;
    }
    try {
      this.isRunning = true;
      const result = await bitcoinClient.getChainTips();
      const tip = result[0].height;
      const latestBlockHeight = await this.$getLatestBlockHeightFromDatabase();
      for (let height = latestBlockHeight + 1; height <= tip; height++) {
        const blockHash: IBitcoinApi.ChainTips = await bitcoinClient.getBlockHash(height);
        const block: IBitcoinApi.Block = await bitcoinClient.getBlock(blockHash, 2);
        await this.$parseBlock(block);
        await this.$saveLatestBlockToDatabase(block.height);
      }
      this.isRunning = false;
    } catch (e) {
      this.isRunning = false;
      throw new Error(e instanceof Error ? e.message : 'Error');
    }
  }

  public async $getPegDataByMonth(): Promise<any> {
    const connection = await DB.getConnection();
    const query = `SELECT SUM(amount) AS amount, DATE_FORMAT(FROM_UNIXTIME(datetime), '%Y-%m-01') AS date FROM elements_pegs GROUP BY DATE_FORMAT(FROM_UNIXTIME(datetime), '%Y%m')`;
    const [rows] = await connection.query<any>(query);
    connection.release();
    return rows;
  }

  protected async $parseBlock(block: IBitcoinApi.Block) {
    for (const tx of block.tx) {
      await this.$parseInputs(tx, block);
      await this.$parseOutputs(tx, block);
    }
  }

  protected async $parseInputs(tx: IBitcoinApi.Transaction, block: IBitcoinApi.Block) {
    for (const [index, input] of tx.vin.entries()) {
      if (input.is_pegin) {
        await this.$parsePegIn(input, index, tx.txid, block);
      }
    }
  }

  protected async $parsePegIn(input: IBitcoinApi.Vin, vindex: number, txid: string, block: IBitcoinApi.Block) {
    const bitcoinTx: IBitcoinApi.Transaction = await bitcoinSecondClient.getRawTransaction(input.txid, true);
    const prevout = bitcoinTx.vout[input.vout || 0];
    const outputAddress = prevout.scriptPubKey.address || (prevout.scriptPubKey.addresses && prevout.scriptPubKey.addresses[0]) || '';
    await this.$savePegToDatabase(block.height, block.time, prevout.value * 100000000, txid, vindex,
      outputAddress, bitcoinTx.txid, prevout.n, 1);
  }

  protected async $parseOutputs(tx: IBitcoinApi.Transaction, block: IBitcoinApi.Block) {
    for (const output of tx.vout) {
      if (output.scriptPubKey.pegout_chain) {
        await this.$savePegToDatabase(block.height, block.time, 0 - output.value * 100000000, tx.txid, output.n,
          (output.scriptPubKey.pegout_addresses && output.scriptPubKey.pegout_addresses[0] || ''), '', 0, 0);
      }
      if (!output.scriptPubKey.pegout_chain && output.scriptPubKey.type === 'nulldata'
        && output.value && output.value > 0 && output.asset && output.asset === Common.nativeAssetId) {
        await this.$savePegToDatabase(block.height, block.time, 0 - output.value * 100000000, tx.txid, output.n,
          (output.scriptPubKey.pegout_addresses && output.scriptPubKey.pegout_addresses[0] || ''), '', 0, 1);
      }
    }
  }

  protected async $savePegToDatabase(height: number, blockTime: number, amount: number, txid: string,
    txindex: number, bitcoinaddress: string, bitcointxid: string, bitcoinindex: number, final_tx: number): Promise<void> {
    const connection = await DB.getConnection();
    const query = `INSERT INTO elements_pegs(
        block, datetime, amount, txid, txindex, bitcoinaddress, bitcointxid, bitcoinindex, final_tx
      ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`;

    const params: (string | number)[] = [
      height, blockTime, amount, txid, txindex, bitcoinaddress, bitcointxid, bitcoinindex, final_tx
    ];
    await connection.query(query, params);
    connection.release();
    logger.debug(`Saved L-BTC peg from block height #${height} with TXID ${txid}.`);
  }

  protected async $getLatestBlockHeightFromDatabase(): Promise<number> {
    const connection = await DB.getConnection();
    const query = `SELECT number FROM state WHERE name = 'last_elements_block'`;
    const [rows] = await connection.query<any>(query);
    connection.release();
    return rows[0]['number'];
  }

  protected async $saveLatestBlockToDatabase(blockHeight: number) {
    const connection = await DB.getConnection();
    const query = `UPDATE state SET number = ? WHERE name = 'last_elements_block'`;
    await connection.query<any>(query, [blockHeight]);
    connection.release();
  }
}

export default new ElementsParser();