/* eslint-disable */
import address from 'address';
import url from 'url';
import chalk from 'chalk';
import formatWebpackMessages from 'react-dev-utils/formatWebpackMessages';
import clearConsole from './clearConsole';

const isInteractive = process.stdout.isTTY;
let handleCompile;

// You can safely remove this after ejecting.
// We only use this block for testing of Create React App itself:
const isSmokeTest = process.argv.some(arg => arg.indexOf('--smoke-test') > -1);
if (isSmokeTest) {
  handleCompile = (err, stats) => {
    if (err || stats.hasErrors() || stats.hasWarnings()) {
      process.exit(1);
    } else {
      process.exit(0);
    }
  };
}

function prepareUrls(protocol, host, port) {
  const formatUrl = hostname =>
    url.format({
      protocol,
      hostname,
      port,
      pathname: '/',
    });
  const prettyPrintUrl = hostname =>
    url.format({
      protocol,
      hostname,
      port: chalk.bold(port),
      pathname: '/',
    });

  const isUnspecifiedHost = host === '0.0.0.0' || host === '::';
  let prettyHost, lanUrlForConfig, lanUrlForTerminal;
  if (isUnspecifiedHost) {
    prettyHost = 'localhost';
    try {
      // This can only return an IPv4 address
      lanUrlForConfig = address.ip();
      if (lanUrlForConfig) {
        // Check if the address is a private ip
        // https://en.wikipedia.org/wiki/Private_network#Private_IPv4_address_spaces
        if (
          /^10[.]|^172[.](1[6-9]|2[0-9]|3[0-1])[.]|^192[.]168[.]/.test(
            lanUrlForConfig,
          )
        ) {
          // Address is private, format it for later use
          lanUrlForTerminal = prettyPrintUrl(lanUrlForConfig);
        } else {
          // Address is not private, so we will discard it
          lanUrlForConfig = undefined;
        }
      }
    } catch (_e) {
      // ignored
    }
  } else {
    prettyHost = host;
  }
  const localUrlForTerminal = prettyPrintUrl(prettyHost);
  const localUrlForBrowser = formatUrl(prettyHost);
  return {
    lanUrlForConfig,
    lanUrlForTerminal,
    localUrlForTerminal,
    localUrlForBrowser,
  };
}

function printInstructions(appName, urls, useYarn) {
  console.log();
  console.log(`You can now view ${chalk.bold(appName)} in the browser.`);
  console.log();

  if (urls.lanUrlForTerminal) {
    console.log(
      `  ${chalk.bold('Local:')}            ${urls.localUrlForTerminal}`,
    );
    console.log(
      `  ${chalk.bold('On Your Network:')}  ${urls.lanUrlForTerminal}`,
    );
  } else {
    console.log(`  ${urls.localUrlForTerminal}`);
  }

  console.log();
  console.log('Note that the development build is not optimized.');
  console.log(
    `To create a production build, use ` +
      `${chalk.cyan(`${useYarn ? 'yarn' : 'npm run'} build`)}.`,
  );
  console.log();
}

function createCompiler(webpack, config, appName, urls, useYarn) {
  // "Compiler" is a low-level interface to Webpack.
  // It lets us listen to some events and provide our own custom messages.
  let compiler;
  try {
    compiler = webpack(config, handleCompile);
  } catch (err) {
    console.log(chalk.red('Failed to compile.'));
    console.log();
    console.log(err.stack);
    console.log();
    process.exit(1);
  }

  // "invalid" event fires when you have changed a file, and Webpack is
  // recompiling a bundle. WebpackDevServer takes care to pause serving the
  // bundle, so if you refresh, it'll wait instead of serving the old one.
  // "invalid" is short for "bundle invalidated", it doesn't imply any errors.
  compiler.plugin('invalid', () => {
    if (isInteractive) {
      clearConsole();
    }
    console.log('Compiling...');
  });

  let isFirstCompile = true;

  // "done" event fires when Webpack has finished recompiling the bundle.
  // Whether or not you have warnings or errors, you will get this event.
  compiler.plugin('done', stats => {
    if (isInteractive) {
      clearConsole();
    }

    // We have switched off the default Webpack output in WebpackDevServer
    // options so we are going to "massage" the warnings and errors and present
    // them in a readable focused way.
    const messages = formatWebpackMessages(stats.toJson({}, true));
    const isSuccessful = !messages.errors.length && !messages.warnings.length;
    if (isSuccessful) {
      console.log(chalk.green('Compiled successfully!'));
    }
    if (isSuccessful && (isInteractive || isFirstCompile)) {
      printInstructions(appName, urls, useYarn);
    }
    isFirstCompile = false;

    // If errors exist, only show errors.
    if (messages.errors.length) {
      // Only keep the first error. Others are often indicative
      // of the same problem, but confuse the reader with noise.
      if (messages.errors.length > 1) {
        messages.errors.length = 1;
      }
      console.log(chalk.red('Failed to compile.\n'));
      console.log(messages.errors.join('\n\n'));
      return;
    }

    // Show warnings if no errors were found.
    if (messages.warnings.length) {
      console.log(chalk.yellow('Compiled with warnings.\n'));
      console.log(messages.warnings.join('\n\n'));

      // Teach some ESLint tricks.
      console.log(
        '\nSearch for the ' +
          chalk.underline(chalk.yellow('keywords')) +
          ' to learn more about each warning.',
      );
      console.log(
        'To ignore, add ' +
          chalk.cyan('// eslint-disable-next-line') +
          ' to the line before.\n',
      );
    }
  });
  return compiler;
}

function resolveLoopback(proxy) {
  const o = url.parse(proxy);
  o.host = undefined;
  if (o.hostname !== 'localhost') {
    return proxy;
  }
  // Unfortunately, many languages (unlike node) do not yet support IPv6.
  // This means even though localhost resolves to ::1, the application
  // must fall back to IPv4 (on 127.0.0.1).
  // We can re-enable this in a few years.
  /*try {
    o.hostname = address.ipv6() ? '::1' : '127.0.0.1';
  } catch (_ignored) {
    o.hostname = '127.0.0.1';
  }*/

  try {
    // Check if we're on a network; if we are, chances are we can resolve
    // localhost. Otherwise, we can just be safe and assume localhost is
    // IPv4 for maximum compatibility.
    if (!address.ip()) {
      o.hostname = '127.0.0.1';
    }
  } catch (_ignored) {
    o.hostname = '127.0.0.1';
  }
  return url.format(o);
}

// We need to provide a custom onError function for httpProxyMiddleware.
// It allows us to log custom error messages on the console.
function onProxyError(proxy) {
  return (err, req, res) => {
    const host = req.headers && req.headers.host;
    console.log(
      chalk.red('Proxy error:') +
        ' Could not proxy request ' +
        chalk.cyan(req.url) +
        ' from ' +
        chalk.cyan(host) +
        ' to ' +
        chalk.cyan(proxy) +
        '.',
    );
    console.log(
      'See https://nodejs.org/api/errors.html#errors_common_system_errors for more information (' +
        chalk.cyan(err.code) +
        ').',
    );
    console.log();

    // And immediately send the proper error response to the client.
    // Otherwise, the request will eventually timeout with ERR_EMPTY_RESPONSE on the client side.
    if (res.writeHead && !res.headersSent) {
      res.writeHead(500);
    }
    res.end(
      'Proxy error: Could not proxy request ' +
        req.url +
        ' from ' +
        host +
        ' to ' +
        proxy +
        ' (' +
        err.code +
        ').',
    );
  };
}

module.exports = {
  createCompiler,
  prepareUrls,
};