/*
  TruffleConfig Paths
  ===========================
  build_directory            /users/myPath/to/someProject/build
  contracts_directory.       /users/myPath/to/someProject/contracts
  working_directory          /users/myPath/to/someProject
  contracts_build_directory  /users/myPath/to/someProject/build/contracts

  Compilation options override
  ----------------------------
  build_directory            /users/myPath/to/someProject/.coverageArtifacts
  contracts_directory        /users/myPath/to/someProject/.coverageContracts

  Test options override
  ---------------------
  contracts_directory,       /users/myPath/to/someProject/.coverageContracts
  contracts_build_directory, /users/myPath/to/someProject/.coverageArtifacts/contracts
  provider                   ganache.provider (async b/c vm must be resolved)
  logger                     add filter for unused variables...

  Truffle Lib API
  ===============
  load:         const truffle = require("truffle") (or require("sc-truffle"))
  compilation:  await truffle.contracts.compile(config)
  test:         await truffle.test.run(config)
*/

const App = require('./../lib/app');
const req = require('req-cwd');
const death = require('death');
const path = require('path');
const dir = require('node-dir');
const Web3 = require('web3');
const util = require('util');
const ganache = require('ganache-core-sc');

async function plugin(truffleConfig){
  let app;
  let error;
  let testsErrored = false;

  try {
    // Load truffle lib & coverage config
    const truffle = loadTruffleLibrary();

    const coverageConfigPath = path.join(truffleConfig.working_directory, '.solcover.js');
    const coverageConfig = req.silent(coverageConfigPath) || {};

    coverageConfig.cwd = truffleConfig.working_directory;
    coverageConfig.contractsDir = truffleConfig.contracts_directory;

    // Start
    app = new App(coverageConfig);
    death(app.cleanUp);

    // Write instrumented sources to temp folder
    app.instrument();

    // Ask truffle to use temp folders
    truffleConfig.contracts_directory = paths.contracts(app);
    truffleConfig.build_directory = paths.build(app);
    truffleConfig.contracts_build_directory = paths.artifacts(truffleConfig, app);

    // Additional config
    truffleConfig.all = true;
    truffleConfig.test_files = tests(truffleConfig);
    truffleConfig.compilers.solc.settings.optimizer.enabled = false;

    // Compile
    await truffle.contracts.compile(truffleConfig);

    // Launch in-process provider
    const networkName = 'soliditycoverage';
    const provider = await app.provider(ganache);
    const accounts = await (new Web3(provider)).eth.getAccounts();

    truffleConfig.network = networkName;

    // Truffle alternately complains that fields are and
    // are not manually set
    try {
      truffleConfig.network_id = "*";
      truffleConfig.provider = provider;
    } catch (err){}

    truffleConfig.networks[networkName] = {
      network_id: "*",
      provider: provider,
      gas: app.gasLimit,
      gasPrice: app.gasPrice,
      from: accounts[0]
    }

    // Run tests
    try {
      failures = await truffle.test.run(truffleConfig)
    } catch (e) {
      error = e.stack;
    }

    // Run Istanbul
    await app.report();

  } catch(e){
    error = e;
  }

  // Finish
  await app.cleanUp();

  if (error !== undefined) throw new Error(error)
  if (failures > 0) throw new Error(`${failures} test(s) failed under coverage.`)
}

// -------------------------------------- Helpers --------------------------------------------------

function tests(truffle){
  const regex = /.*\.(js|ts|es|es6|jsx|sol)$/;
  const files = dir.files(truffle.test_directory, { sync: true }) || [];
  return files.filter(f => f.match(regex) != null);
}


function loadTruffleLibrary(){

  try { return require("truffle") }   catch(err) {};
  try { return require("./truffle.library")} catch(err) {};

  throw new Error('Missing truffle lib...')
}

/**
 * Functions to generate substitute paths for instrumented contracts and artifacts.
 * @type {Object}
 */
const paths = {
  // "contracts_directory":
  contracts: (app) => {
     return path.join(
      app.coverageDir,
      app.contractsDirName
    )
  },

  // "build_directory":
  build: (app) => {
    return path.join(
      app.coverageDir,
      app.artifactsDirName
    )
  },

  // "contracts_build_directory":
  artifacts: (truffle, app) => {
    return path.join(
      app.coverageDir,
      app.artifactsDirName,
      path.basename(truffle.contracts_build_directory)
    )
  }
}

module.exports = plugin;