/* eslint-disable no-console */

const fse = require('fs-extra')
const path = require('path')
const globber = require('glob')
const Promise = require('bluebird')
const la = require('lazy-ass')
const is = require('check-more-types')
const debug = require('debug')('cypress:link')
const _ = require('lodash')

const isRelative = (s) => !path.isAbsolute(s)

const fs = Promise.promisifyAll(fse)
const glob = Promise.promisify(globber)

const pathToPackages = path.join('node_modules', '@packages')

function deleteOutputFolder () {
  const wildcard = `${pathToPackages}/*`
  console.log('deleting all', wildcard)
  return glob(wildcard)
    .map((filename) => fs.unlinkAsync(filename))
    .catch(_.noop)
}

function proxyModule (name, pathToMain, pathToBrowser) {
  la(is.unemptyString(name), 'missing name')
  la(is.unemptyString(pathToMain), 'missing path to main', pathToMain)
  la(isRelative(pathToMain), 'path to main should be relative', pathToMain)

  const pkg = {
    name,
    version: '0.0.0',
    description: `fake proxy module ${name}`,
    main: pathToMain,
  }
  if (pathToBrowser) {
    la(isRelative(pathToBrowser),
      'path to browser module should be relative', pathToBrowser)
    pkg.browser = pathToBrowser
  }

  return pkg
}

function proxyRegister (name) {
  return `module.exports = require('../../../packages/${name}/register')`
}

function needsRegister (name) {
  return name === '@packages/coffee' || name === '@packages/ts'
}

function makeProxies () {
  return glob('./packages/*/package.json')
  .map((filename) =>
    fs.readJsonAsync(filename)
    .then((json) => ({ filename, json }))
  )
  .map(({ filename, json }) => {
    if (!json.main) {
      throw new Error(`Package ${json.name} is missing main`)
    }
    const dirname = path.dirname(filename)
    const bareName = json.name.split('/')[1]
    debug(json.name, 'bare name', bareName, 'main', json.main)
    const destinationFolder = path.join(pathToPackages, bareName)
    const destPackageFilename = path.join(destinationFolder, 'package.json')
    const registerPath = path.join(destinationFolder, 'register.js')
    const fullMain = path.resolve(dirname, json.main)
    debug('full name', fullMain)
    const relativePathToMain = path.relative(destinationFolder, fullMain)
    debug('relative path to main', relativePathToMain)

    // for browserify, some packages use "browser" field
    // need to pass it as well
    let relativePathToBrowser
    if (is.unemptyString(json.browser)) {
      debug('package has browser field %s', json.browser)
      relativePathToBrowser = path.relative(destinationFolder,
        path.resolve(dirname, json.browser)
      )
      debug('relative path to browser', relativePathToBrowser)
    }

    const proxy = proxyModule(json.name, relativePathToMain, relativePathToBrowser)
    console.log(path.dirname(destPackageFilename), '->', relativePathToMain)

    return fs.outputJsonAsync(destPackageFilename, proxy)
      .then(() => {
        if (needsRegister(json.name)) {
          console.log('adding register file', registerPath)
          return fs.outputFileAsync(registerPath, proxyRegister(bareName), 'utf8')
        }
      })
  })
}

function linkPackages () {
  return deleteOutputFolder()
  .then(makeProxies)
  .then(() => {
    console.log('✅  require("@packages/<name>") should work now!')
  })
}

module.exports = linkPackages

if (!module.parent) {
  linkPackages()
}