const util = require('util');
const Web3 = require('web3');
const metamgr = require('./metamgr');
const utils = require('./utils');
const sync = require("./sync");
const log = require("./log");
const C = require("./C");

class BlockChain {

  constructor() {
    this.currBlockNumber = 0;
    this.refreshCond = new sync.Cond();
    this.lastRefreshTime = utils.getUtcTime();
    this.actived = false;
  }

  async initInstance(user, address, jsonUrl) {
    const json = utils.readJsonFromFile(jsonUrl);
    return new this.web3.eth.Contract(
      json.abi,
      address,
      { from: user }
    );
  }

  async init() {
    this.web3 = new Web3(metamgr.getWeb3Conf()['block_server']);
    this.web3.eth.accounts.wallet.add(metamgr.getWalletAccount());
    for (const data of metamgr.getContracts()) {
      this[`${data.name}Instance`] = await this.initInstance
      (metamgr.getUserAddress(), data.address, data.json);
    }
    setTimeout(this.refreshBlockNumber.bind(this), 1000 * 0.01);
    await this.mustBeActive();
    utils.emitEvent(C.BC_INITIALIZED_EVENT);
  }

  async mustBeActive() {
    while (!this.actived) {
      await utils.sleep(1000);
    }
  }

  async refreshBlockNumber() {
    const logClass = 'refreshBlockNumber';
    while (true) {
      try {
        this.currBlockNumber = await this.web3.eth.getBlockNumber();
        this.actived = true;
        this.lastRefreshTime = utils.getUtcTime();
      } catch (e) {
        this.actived = false;
        log.warning(util.format('%s err:%s',
                                logClass,
                                e
                               ));
      }
      await this.refreshCond.wait(1000 * 3);
    }
  }

  getCurrBlockNumber() {
    return this.currBlockNumber;
  }

}

module.exports = new BlockChain();