import { log } from '../log'
import { FoundBrowser, Browser, NotInstalledError } from '../types'
import * as execa from 'execa'
import { normalize, join } from 'path'
import { trim, tap } from 'ramda'
import { pathExists } from 'fs-extra'
import { homedir } from 'os'

const notInstalledErr = (name: string) => {
  const err: NotInstalledError = new Error(
    `Browser not installed: ${name}`
  ) as NotInstalledError
  err.notInstalled = true
  return err
}

function formFullAppPath(name: string) {
  const prefix = 'C:/Program Files (x86)/Google/Chrome/Application'
  return normalize(join(prefix, `${name}.exe`))
}

function formChromiumAppPath() {
  const exe = 'C:/Program Files (x86)/Google/chrome-win32/chrome.exe'
  return normalize(exe)
}

function formChromeCanaryAppPath() {
  const home = homedir()
  const exe = join(
    home,
    'AppData',
    'Local',
    'Google',
    'Chrome SxS',
    'Application',
    'chrome.exe'
  )
  return normalize(exe)
}

type NameToPath = (name: string) => string

interface WindowsBrowserPaths {
  [index: string]: NameToPath
  chrome: NameToPath
  canary: NameToPath
  chromium: NameToPath
}

const formPaths: WindowsBrowserPaths = {
  chrome: formFullAppPath,
  canary: formChromeCanaryAppPath,
  chromium: formChromiumAppPath
}

function getWindowsBrowser(
  name: string,
  binary: string
): Promise<FoundBrowser> {
  const getVersion = (stdout: string): string => {
    // result from wmic datafile
    // "Version=61.0.3163.100"
    const wmicVersion = /^Version=(\S+)$/
    const m = wmicVersion.exec(stdout)
    if (m) {
      return m[1]
    }
    log('Could not extract version from %s using regex %s', stdout, wmicVersion)
    throw notInstalledErr(binary)
  }

  const formFullAppPathFn: any = formPaths[name] || formFullAppPath
  const exePath = formFullAppPathFn(name)
  log('exe path %s', exePath)

  const doubleEscape = (s: string) => s.replace(/\\/g, '\\\\')

  return pathExists(exePath)
    .then(exists => {
      log('found %s ?', exePath, exists)
      if (!exists) {
        throw notInstalledErr(`Browser ${name} file not found at ${exePath}`)
      }
      // on Windows using "--version" seems to always start the full
      // browser, no matter what one does.
      const args: [string] = [
        'datafile',
        'where',
        `name="${doubleEscape(exePath)}"`,
        'get',
        'Version',
        '/value'
      ]
      return execa('wmic', args)
        .then(result => result.stdout)
        .then(trim)
        .then(tap(log))
        .then(getVersion)
        .then((version: string) => {
          log("browser %s at '%s' version %s", name, exePath, version)
          return {
            name,
            version,
            path: exePath
          }
        })
    })
    .catch(() => {
      throw notInstalledErr(name)
    })
}

export function detectBrowserWindows(browser: Browser) {
  return getWindowsBrowser(browser.name, browser.binary)
}