/*global web3*/
const fs = require('fs');
const process = require('process');

const ContractSources = require('./contract_sources');

// Set up the web3 extension
web3.extend({
  property: 'debug',
  methods: [{name: 'traceTransaction', call: 'debug_traceTransaction', params: 2}]
});

class CodeCoverage {
  constructor(embark, _options) {
    this.events = embark.events;
    this.logger = embark.logger;

    embark.events.on('contracts:compile:solc', this.compileSolc.bind(this));
    embark.events.on('contracts:compiled:solc', this.compiledSolc.bind(this));
    embark.events.on('contracts:run:solc', this.runSolc.bind(this));
    embark.events.on('block:header', this.runSolc.bind(this));

    this.seenTransactions = {};

    var self = this;
    process.on('exit', (code) => {
      fs.writeFileSync('/tmp/coverage.json', JSON.stringify(this.coverageReport));
    });
  }

  compileSolc(input) {
    var sources = {};

    Object.keys(input.sources).forEach((path) => {
      sources[path] = input.sources[path].content;
    });

    this.contractSources = new ContractSources(sources);
  }

  compiledSolc(output) {
    this.contractSources.parseSolcOutput(output);
  }

  async runSolc(receipt) {
    var block = await web3.eth.getBlock(receipt.number);
    for(var i in block.transactions) {
      var txHash = block.transactions[i];

      if(this.seenTransactions[txHash]) return;

      this.seenTransactions[txHash] = true;
      var trace = await web3.debug.traceTransaction(txHash, {});
      var cov = this.contractSources.generateCodeCoverage(trace);
      this.coverageReport = cov;
    }
  }
}

module.exports = CodeCoverage;