'use strict'

const assert = require('assert')
const downloadFileFromGithub = require('./download-file-from-github')
const fs = require('fs-extra')
const path = require('path')
const semver = require('semver')
const spawnSync = require('./spawn-sync')
const syncRequest = require('sync-request')

const CONFIG = require('../config')

module.exports = function () {
  if (process.platform === 'darwin') {
    // Chromedriver is only distributed with the first patch release for any given
    // major and minor version of electron.
    const electronVersion = semver.parse(CONFIG.appMetadata.electronVersion)
    const electronVersionWithChromedriver = `${electronVersion.major}.${electronVersion.minor}.0`
    const electronAssets = getElectronAssetsForVersion(electronVersionWithChromedriver)
    const chromedriverAssets = electronAssets.filter(e => /chromedriver.*darwin-x64/.test(e.name))
    assert(chromedriverAssets.length === 1, 'Found more than one chrome driver asset to download!')
    const chromedriverAsset = chromedriverAssets[0]

    const chromedriverZipPath = path.join(CONFIG.electronDownloadPath, `electron-${electronVersionWithChromedriver}-${chromedriverAsset.name}`)
    if (!fs.existsSync(chromedriverZipPath)) {
      downloadFileFromGithub(chromedriverAsset.url, chromedriverZipPath)
    }

    const chromedriverDirPath = path.join(CONFIG.electronDownloadPath, 'chromedriver')
    unzipPath(chromedriverZipPath, chromedriverDirPath)
  } else {
    console.log('Skipping Chromedriver download because it is used only on macOS'.gray)
  }
}

function getElectronAssetsForVersion (version) {
  const releaseURL = `https://api.github.com/repos/electron/electron/releases/tags/v${version}`
  const response = syncRequest('GET', releaseURL, {'headers': {'User-Agent': 'Atom Build'}})

  if (response.statusCode === 200) {
    const release = JSON.parse(response.body)
    return release.assets.map(a => { return {name: a.name, url: a.browser_download_url} })
  } else {
    throw new Error(`Error getting assets for ${releaseURL}. HTTP Status ${response.statusCode}.`)
  }
}

function unzipPath (inputPath, outputPath) {
  if (fs.existsSync(outputPath)) {
    console.log(`Removing "${outputPath}"`)
    fs.removeSync(outputPath)
  }

  console.log(`Unzipping "${inputPath}" to "${outputPath}"`)
  spawnSync('unzip', [inputPath, '-d', outputPath])
}