import { pathExists } from 'fs-extra'
import { resolve } from 'path'
import execa from 'execa'

export function isGitRepo(cwd = '.'): Promise<boolean> {
  return pathExists(resolve(cwd, '.git'))
}

export async function getCurrGitBranch(cwd?: string): Promise<string> {
  // https://stackoverflow.com/questions/6245570/how-to-get-the-current-branch-name-in-git/6245587#6245587
  // git rev-parse --abbrev-ref HEAD
  const obj = await execa('git', ['rev-parse', '--abbrev-ref', 'HEAD'], { cwd })
  return obj.stdout
}

export async function getUnpushedGitCommits(cwd?: string): Promise<string> {
  try {
    const branch = await getCurrGitBranch(cwd)
    // https://stackoverflow.com/questions/2016901/viewing-unpushed-git-commits
    // git log @{u}..
    // @{u} won't work if the local branch isn't configured with an upstream. WTF...
    const obj = await execa('git', ['log', `origin/${branch}..${branch}`], {
      cwd,
    })
    return obj.stdout
  } catch (err) {
    return ''
  }
}

export async function hasUnpushedGitCommits(cwd?: string): Promise<boolean> {
  return !!(await getUnpushedGitCommits(cwd))
}

export async function getGitStatus(cwd?: string): Promise<string> {
  // git status --porcelain
  const obj = await execa('git', ['status', '--porcelain'], { cwd })
  return obj.stdout
}

export async function gitIsClean(cwd?: string): Promise<boolean> {
  return !(await getGitStatus(cwd))
}

export async function gitNotClean(cwd?: string): Promise<boolean> {
  return !!(await getGitStatus(cwd))
}

export async function ensureGitClean(cwd?: string): Promise<void> {
  if (!(await isGitRepo(cwd))) {
    throw new Error('未检测到 git')
  } else if (await gitNotClean(cwd)) {
    throw new Error('检测到有未提交的文件, 请先提交文件.')
  }
}

export async function getGitUrl() {
  // https://stackoverflow.com/questions/15715825/how-do-you-get-the-git-repositorys-name-in-some-git-repository/42543006#42543006
  // git config --get remote.origin.url
  const { stdout } = await execa('git', [
    'config',
    '--get',
    'remote.origin.url',
  ])
  return stdout.trim()
}

export function parseGitUrl(url: string) {
  if (url.indexOf('git') === 0) {
    let str = url.split(':')[1]
    str = str.replace('.git', '')
    const names = str.split('/')
    return { groupName: names[0], projectName: names[1] }
  }

  if (url.indexOf('http') === 0) {
    let str = url
    str = str.replace('.git', '')
    const names = str.split('/')
    const n = names.length
    return { groupName: names[n - 2], projectName: names[n - 1] }
  }

  return { groupName: '', projectName: '' }
}

export async function getGitNames() {
  const url = await getGitUrl()
  return parseGitUrl(url)
}

export async function getGitBranch() {
  const { stdout } = await execa('git', ['rev-parse', '--abbrev-ref', 'HEAD'])
  return stdout.trim()
}