// Native
const path = require('path')
const url = require('url')
const childProcess = require('child_process')

// Packages
const fs = require('fs-extra')
const download = require('download')
const tmp = require('tmp-promise')
const isURL = require('is-url')

const cloneRepo = (parts, tmpDir) =>
  new Promise((resolve, reject) => {
    let host

    switch (parts.type) {
      case 'GitLab':
        host = `gitlab.com`
        break
      case 'Bitbucket':
        host = `bitbucket.org`
        break
      default:
        host = `github.com`
    }

    const url = `https://${host}/${parts.main}`
    const ref = parts.ref || (parts.type === 'Bitbucket' ? 'default' : 'master')
    const cmd = `git clone ${url} --single-branch ${ref}`

    childProcess.exec(cmd, { cwd: tmpDir.path }, (err, stdout) => {
      if (err) {
        reject(err)
      }

      resolve(stdout)
    })
  })

const renameRepoDir = async (pathParts, tmpDir) => {
  const tmpContents = await fs.readdir(tmpDir.path)

  const oldTemp = path.join(tmpDir.path, tmpContents[0])
  const newTemp = path.join(tmpDir.path, pathParts.main.replace('/', '-'))

  await fs.rename(oldTemp, newTemp)
  tmpDir.path = newTemp

  return tmpDir
}

const capitalizePlatform = name => {
  const names = {
    github: 'GitHub',
    gitlab: 'GitLab',
    bitbucket: 'Bitbucket'
  }

  return names[name]
}

const splittedURL = fullURL => {
  const parsedURL = url.parse(fullURL)
  const pathParts = parsedURL.path.split('/')

  pathParts.shift()

  // Set path to repo...
  const main = pathParts[0] + '/' + pathParts[1]

  // ...and then remove it from the parts
  pathParts.splice(0, 2)

  // Assign Git reference
  let ref = pathParts.length >= 2 ? pathParts[1] : ''

  // Firstly be sure that we haven know the ref type
  if (pathParts[0]) {
    // Then shorten the SHA of the commit
    if (pathParts[0] === 'commit' || pathParts[0] === 'commits') {
      ref = ref.substring(0, 7)
    }
  }

  // We're deploying master by default,
  // so there's no need to indicate it explicitly
  if (ref === 'master') {
    ref = ''
  }

  return {
    main,
    ref,
    type: capitalizePlatform(parsedURL.host.split('.')[0])
  }
}

const gitPathParts = main => {
  let ref = ''

  if (isURL(main)) {
    return splittedURL(main)
  }

  if (main.split('/')[1].includes('#')) {
    const parts = main.split('#')

    ref = parts[1]
    main = parts[0]
  }

  return {
    main,
    ref,
    type: capitalizePlatform('github')
  }
}

const downloadRepo = async repoPath => {
  const pathParts = gitPathParts(repoPath)

  const tmpDir = await tmp.dir({
    // We'll remove it manually once deployment is done
    keep: true,
    // Recursively remove directory when calling respective method
    unsafeCleanup: true
  })

  let gitInstalled = true

  try {
    await cloneRepo(pathParts, tmpDir)
  } catch (err) {
    gitInstalled = false
  }

  if (gitInstalled) {
    const renaming = await renameRepoDir(pathParts, tmpDir)
    return renaming
  }

  let url

  switch (pathParts.type) {
    case 'GitLab': {
      const ref = pathParts.ref ? `?ref=${pathParts.ref}` : ''
      url = `https://gitlab.com/${pathParts.main}/repository/archive.tar` + ref
      break
    }
    case 'Bitbucket':
      url = `https://bitbucket.org/${pathParts.main}/get/${pathParts.ref || 'default'}.zip`
      break
    default:
      url = `https://api.github.com/repos/${pathParts.main}/tarball/${pathParts.ref}`
  }

  try {
    await download(url, tmpDir.path, {
      extract: true
    })
  } catch (err) {
    tmpDir.cleanup()
    return false
  }

  const renaming = await renameRepoDir(pathParts, tmpDir)
  return renaming
}

const isRepoPath = path => {
  if (!path) {
    return false
  }

  const allowedHosts = ['github.com', 'gitlab.com', 'bitbucket.org']

  if (isURL(path)) {
    const urlParts = url.parse(path)
    const slashSplitted = urlParts.path.split('/').filter(n => n)
    const notBare = slashSplitted.length >= 2

    if (allowedHosts.includes(urlParts.host) && notBare) {
      return true
    }

    const err = new Error(`Host "${urlParts.host}" is unsupported.`)
    err.code = 'INVALID_URL'
    err.userError = true
    throw err
  }

  return /[^\s\\]\/[^\s\\]/g.test(path)
}

const fromGit = async (path, debug) => {
  let tmpDir = false

  try {
    tmpDir = await downloadRepo(path)
  } catch (err) {
    if (debug) {
      console.log(`Could not download "${path}" repo from GitHub`)
    }
  }

  return tmpDir
}

module.exports = {
  gitPathParts,
  isRepoPath,
  fromGit
}