const app = require('j7/app');
const utils = require('j7/utils');
const bcutils = require('j7/bcutils');
const log = require('j7/log');
const bc = require('../blockchain');

class EventProcess extends BaseService {

  async init(instance, cb) {
    this.instance = instance;
    this.cb = cb;
  }

  async start() {
    while (true) {
      await this.pullEvent();
      await utils.sleep(8000 + utils.randRange(500, 1500));
    }
  }

  async pullEvent() {
    const logClass = this.getInstanceName() + ' pullEvent:';
    while (true) {
      try {
        const fromBlock = await getFromBlock();
        const toBlock = fromBlock + 3000;
        const events = await bc[this.getInstanceName()].getPastEvents(
          this.instance['eventName'],
          {
            fromBlock: fromBlock,
            toBlock: toBlock,
          },
        );
        await this.processEvents(events, toBlock);
        await this.saveLastBlockNumber(toBlock);
        return;
      } catch (err) {
        log.error(logClass + err);
      }
    }
    await utils.sleep(2000 + utils.randRange(500, 1500));
  }

  getInstanceName() {
    return this.instance['name'];
  }

  async processEvents(events, toBlock) {
    this.instance['last_block_number'] = toBlock;
    for (let i in events) {
      while (true) {
        try {
          await cb(event);
          break;
        } catch (err) {
        }
        await utils.sleep(8000 + utils.randRange(500, 1500));
      }
    }
  }

  async getFromBlock() {

  }

  async saveLastBlockNumber(blockNumber) {

  }

}


module.exports = EventProcess;