// @remove-file-on-eject
/**
 * Copyright (c) 2015-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

import * as chalk from 'chalk'
import * as fs from 'fs'
import * as path from 'path'

// We assume that having wrong versions of these
// in the tree will likely break your setup.
// This is a relatively low-effort way to find common issues.
function verifyPackageTree() {
  const depsToCheck = [
    // These are packages most likely to break in practice.
    // I have not included Babel here because plugins typically don't import Babel (so it's not affected).
    'webpack',
    'webpack-dev-server'
  ]
  // Inlined from semver-regex, MIT license.
  // Don't want to make this a dependency after ejecting.
  const getSemverRegex = () =>
    /\bv?(?:0|[1-9]\d*)\.(?:0|[1-9]\d*)\.(?:0|[1-9]\d*)(?:-[\da-z-]+(?:\.[\da-z-]+)*)?(?:\+[\da-z-]+(?:\.[\da-z-]+)*)?\b/gi
  const ownPackageJson = require('../../../package.json')
  const expectedVersionsByDep = {}
  // Gather wanted deps
  depsToCheck.forEach(dep => {
    const expectedVersion = ownPackageJson.dependencies[dep]
    if (!expectedVersion) {
      throw new Error('This dependency list is outdated, fix it.')
    }
    if (!getSemverRegex().test(expectedVersion)) {
      throw new Error(
        `The ${dep} package should be pinned, instead got version ${expectedVersion}.`
      )
    }
    expectedVersionsByDep[dep] = expectedVersion
  })
  // Verify we don't have other versions up the tree
  let currentDir = __dirname
  // eslint-disable-next-line no-constant-condition
  while (true) {
    const previousDir = currentDir
    currentDir = path.resolve(currentDir, '..')
    if (currentDir === previousDir) {
      // We've reached the root.
      break
    }
    const maybeNodeModules = path.resolve(currentDir, 'node_modules')
    if (!fs.existsSync(maybeNodeModules)) {
      // eslint-disable-next-line no-continue
      continue
    }
    depsToCheck.forEach(dep => {
      const maybeDep = path.resolve(maybeNodeModules, dep)
      if (!fs.existsSync(maybeDep)) {
        return
      }
      const maybeDepPackageJson = path.resolve(maybeDep, 'package.json')
      if (!fs.existsSync(maybeDepPackageJson)) {
        return
      }
      const depPackageJson = JSON.parse(
        fs.readFileSync(maybeDepPackageJson, 'utf8')
      )
      const expectedVersion = expectedVersionsByDep[dep]
      if (depPackageJson.version !== expectedVersion) {
        console.error(
          `${chalk.red(
            `\nThere might be a problem with the project dependency tree.\n` +
              `It is likely ${chalk.bold(
                'not'
              )} a bug in Berun, but something you need to fix locally.\n\n`
          )}The ${chalk.bold(
            ownPackageJson.name
          )} package provided by Berun requires a dependency:\n\n${chalk.green(
            `  "${chalk.bold(dep)}": "${chalk.bold(expectedVersion)}"\n\n`
          )}Don't try to install it manually: your package manager does it automatically.\n` +
            `However, a different version of ${chalk.bold(
              dep
            )} was detected higher up in the tree:\n\n` +
            `  ${chalk.bold(chalk.red(maybeDep))} (version: ${chalk.bold(
              chalk.red(depPackageJson.version)
            )}) \n\n` +
            `Manually installing incompatible versions is known to cause hard-to-debug issues.\n` +
            `To fix the dependency tree, try following the steps below in the exact order:\n\n` +
            `  ${chalk.cyan('1.')} Delete ${chalk.bold(
              'package-lock.json'
            )} (${chalk.underline('not')} ${chalk.bold(
              'package.json'
            )}!) and/or ${chalk.bold(
              'yarn.lock'
            )} in your project folder.\n\n` +
            `  ${chalk.cyan('2.')} Delete ${chalk.bold(
              'node_modules'
            )} in your project folder.\n\n` +
            `  ${chalk.cyan('3.')} Remove "${chalk.bold(
              dep
            )}" from ${chalk.bold('dependencies')} and/or ${chalk.bold(
              'devDependencies'
            )} in the ${chalk.bold(
              'package.json'
            )} file in your project folder.\n\n` +
            `  ${chalk.cyan('4.')} Run ${chalk.bold(
              'npm install'
            )} or ${chalk.bold(
              'yarn'
            )}, depending on the package manager you use.\n\n` +
            `In most cases, this should be enough to fix the problem.\n` +
            `If this has not helped, there are a few other things you can try:\n\n` +
            `  ${chalk.cyan('5.')} If you used ${chalk.bold(
              'npm'
            )}, install ${chalk.bold(
              'yarn'
            )} (http://yarnpkg.com/) and repeat the above steps with it instead.\n` +
            `     This may help because npm has known issues with package hoisting which may get resolved in future versions.\n\n` +
            `  ${chalk.cyan('6.')} Check if ${chalk.bold(
              maybeDep
            )} is outside your project directory.\n` +
            `     For example, you might have accidentally installed something in your home folder.\n\n` +
            `  ${chalk.cyan('7.')} Try running ${chalk.bold(
              `npm ls ${dep}`
            )} in your project folder.\n` +
            `     This will tell you which ${chalk.underline(
              'other'
            )} package (apart from the expected ${chalk.bold(
              ownPackageJson.name
            )}) installed ${chalk.bold(dep)}.\n\n` +
            `If nothing else helps, add ${chalk.bold(
              'SKIP_PREFLIGHT_CHECK=true'
            )} to an ${chalk.bold('.env')} file in your project.\n` +
            `That would permanently disable this preflight check in case you want to proceed anyway.\n\n${chalk.cyan(
              `P.S. We know this message is long but please read the steps above :-) We hope you find them helpful!\n`
            )}`
        )
        process.exit(1)
      }
    })
  }
}

export default verifyPackageTree