#!/usr/bin/env node

const now = Date.now()

const { resolve } = require('path')

const {
  readFileSync,
  readJSONSync,
  writeFileSync,
  copySync,
  removeSync
} = require('fs-extra')

// Dirs
const rootDir = resolve(__dirname, '..')
const startDir = resolve(rootDir, 'start')

// Read main package.json
const packageJSON = readJSONSync(resolve(rootDir, 'package.json'))

// Required and Excluded packages for start
let requires = ['minimist']

const excludes = ['path', 'fs', 'http', 'module', 'crypto'].concat(
  Object.keys(packageJSON.devDependencies)
)

// Parse dist/core.js for all external dependencies
const requireRegex = /require\('([-@/\w]+)'\)/g
const rawCore = readFileSync(resolve(rootDir, 'dist/nuxt-start.js'))
let match = requireRegex.exec(rawCore)
while (match) {
  requires.push(match[1])
  match = requireRegex.exec(rawCore)
}

// Apply Excludes
requires = requires.filter(r => excludes.indexOf(r) === -1)

// Resolve version constrains
const dependencies = {}
requires.forEach((r) => {
  if (!packageJSON.dependencies[r]) {
    // eslint-disable-next-line no-console
    console.warn('Cannot resolve dependency version for ' + r)
    return
  }
  dependencies[r] = packageJSON.dependencies[r]
})

// Drop fields
const drops = ['devDependencies', 'scripts', 'nyc', 'types']
drops.forEach(k => delete packageJSON[k])

// Update dependencies
packageJSON.dependencies = dependencies

// Update package meta
packageJSON.name = packageJSON.name + '-start'
packageJSON.description = 'runtime-only build for nuxt'
packageJSON.bin = {
  'nuxt-start': './bin/nuxt-start'
}

// Update package.json
writeFileSync(
  resolve(startDir, 'package.json'),
  JSON.stringify(packageJSON, null, 2)
)

// Copy required files
const excludeFiles = ['README.md', '.gitignore']
packageJSON.files.forEach((file) => {
  if (excludeFiles.indexOf(file) !== -1) {
    return
  }
  const src = resolve(rootDir, file)
  const dst = resolve(startDir, file)
  // console.log(relative(rootDir, src), '~>', relative(rootDir, dst))
  removeSync(dst)
  copySync(src, dst)
})

// Remove extras
const extraFiles = [
  'bin/nuxt-build',
  'bin/nuxt-generate',
  'bin/nuxt-dev',
  'bin/nuxt',
  'dist/nuxt.js',
  'dist/nuxt.js.map'
]
extraFiles.forEach(file => removeSync(resolve(startDir, file)))

// Patch bin/nuxt-start
const binStart = resolve(startDir, 'bin/nuxt-start')
writeFileSync(
  binStart,
  String(readFileSync(binStart)).replace(/nuxt start/g, 'nuxt-start')
)

// eslint-disable-next-line no-console
console.log(
  `Generated ${packageJSON.name}@${packageJSON.version} in ${Date.now() -
    now}ms`
)