const { GitProcess } = require('dugite')
const fs = require('fs')
const path = require('path')

const ELECTRON_DIR = path.resolve(__dirname, '..', '..')
const SRC_DIR = path.resolve(ELECTRON_DIR, '..')

const RELEASE_BRANCH_PATTERN = /(\d)+-(?:(?:[0-9]+-x$)|(?:x+-y$))/

require('colors')
const pass = '✓'.green
const fail = '✗'.red

function getElectronExec () {
  const OUT_DIR = getOutDir()
  switch (process.platform) {
    case 'darwin':
      return `out/${OUT_DIR}/Electron.app/Contents/MacOS/Electron`
    case 'win32':
      return `out/${OUT_DIR}/electron.exe`
    case 'linux':
      return `out/${OUT_DIR}/electron`
    default:
      throw new Error('Unknown platform')
  }
}

function getOutDir (options = {}) {
  const shouldLog = options.shouldLog || false

  if (options.outDir || process.env.ELECTRON_OUT_DIR) {
    const outDir = options.outDir || process.env.ELECTRON_OUT_DIR
    const outPath = path.resolve(SRC_DIR, 'out', outDir)

    // Check that user-set variable is a valid/existing directory
    if (fs.existsSync(outPath)) {
      if (shouldLog) console.log(`OUT_DIR is: ${outDir}`)
      return outDir
    }

    // Throw error if user passed/set nonexistent directory.
    throw new Error(`${outDir} directory not configured on your machine.`)
  } else {
    for (const buildType of ['Testing', 'Release', 'Default', 'Debug']) {
      const outPath = path.resolve(SRC_DIR, 'out', buildType)
      if (fs.existsSync(outPath)) {
        if (shouldLog) console.log(`OUT_DIR is: ${buildType}`)
        return buildType
      }
    }
  }
}

function getAbsoluteElectronExec () {
  return path.resolve(SRC_DIR, getElectronExec())
}

async function handleGitCall (args, gitDir) {
  const details = await GitProcess.exec(args, gitDir)
  if (details.exitCode === 0) {
    return details.stdout.replace(/^\*|\s+|\s+$/, '')
  } else {
    const error = GitProcess.parseError(details.stderr)
    console.log(`${fail} couldn't parse git process call: `, error)
    process.exit(1)
  }
}

async function getCurrentBranch (gitDir) {
  let branch = await handleGitCall(['rev-parse', '--abbrev-ref', 'HEAD'], gitDir)
  if (branch !== 'master' && !RELEASE_BRANCH_PATTERN.test(branch)) {
    const lastCommit = await handleGitCall(['rev-parse', 'HEAD'], gitDir)
    const branches = (await handleGitCall([
      'branch',
      '--contains',
      lastCommit,
      '--remote'
    ], gitDir)).split('\n')

    branch = branches.filter(b => b.trim() === 'master' || RELEASE_BRANCH_PATTERN.test(b.trim()))[0]
    if (!branch) {
      console.log(`${fail} no release branch exists for this ref`)
      process.exit(1)
    }
    if (branch.startsWith('origin/')) branch = branch.substr('origin/'.length)
  }
  return branch.trim()
}

module.exports = {
  getCurrentBranch,
  getElectronExec,
  getOutDir,
  getAbsoluteElectronExec,
  ELECTRON_DIR,
  SRC_DIR
}