'use strict'

// Have you identified a contributing guideline that should be included here?
// Please open a pull request!
//
// To test changes to this file, pick a PR to test against, then run
// `./node_modules/.bin/danger pr pr-url`
// Note that the line numbers in the runtime errors are incorrect.

const { danger, fail, message, warn } = require('danger')
const chainsmoker = require('chainsmoker')
const { default: noTestShortcuts } = require('danger-plugin-no-test-shortcuts')

const fileMatch = chainsmoker({
  created: danger.git.created_files,
  modified: danger.git.modified_files,
  createdOrModified: danger.git.modified_files.concat(danger.git.created_files),
  deleted: danger.git.deleted_files,
})

const documentation = fileMatch(
  '**/*.md',
  'lib/all-badge-examples.js',
  'frontend/components/usage.js'
)
const server = fileMatch('server.js')
const serverTests = fileMatch('server.spec.js')
const helpers = fileMatch(
  'lib/**/*.js',
  '!**/*.spec.js',
  '!lib/all-badge-examples.js'
)
const logos = fileMatch('logo/*.svg')
const helperTests = fileMatch('lib/**/*.spec.js')
const packageJson = fileMatch('package.json')
const packageLock = fileMatch('package-lock.json')
const capitals = fileMatch('**/*[A-Z]*.js')
// _document.js is used by convention by Next.
const underscores = fileMatch('**/*_*.js', '!pages/_document.js')
const targetBranch = danger.github.pr.base.ref

message(
  [
    ':sparkles: Thanks for your contribution to Shields, ',
    `@${danger.github.pr.user.login}!`,
  ].join('')
)

if (targetBranch !== 'master') {
  const message = `This PR targets \`${targetBranch}\``
  const idea = 'It is likely that the target branch should be `master`'
  warn(`${message} - <i>${idea}</i>`)
}

if (documentation.createdOrModified) {
  message(
    [
      'Thanks for contributing to our documentation. ',
      'We :heart: our [documentarians](http://www.writethedocs.org/)!',
    ].join('')
  )
}

if (packageJson.modified && !packageLock.modified) {
  const message = 'This PR modified `package.json`, but not `package-lock.json`'
  const idea = 'Perhaps you need to run `npm install`?'
  warn(`${message} - <i>${idea}</i>`)
}

if (server.modified && !serverTests.modified) {
  warn(
    [
      'This PR modified the server but none of its tests. <br>',
      "That's okay so long as it's refactoring existing code.",
    ].join('')
  )
}

if (helpers.created && !helperTests.created) {
  warn(
    [
      'This PR added helper modules in `lib/` but not accompanying tests. <br>',
      'Generally helper modules should have their own tests.',
    ].join('')
  )
} else if (helpers.createdOrModified && !helperTests.createdOrModified) {
  warn(
    [
      'This PR modified helper functions in `lib/` but not accompanying tests. <br>',
      "That's okay so long as it's refactoring existing code.",
    ].join('')
  )
}

if (logos.created) {
  message(
    [
      ':art: Thanks for submitting a logo. <br>',
      'Please ensure your contribution follows our ',
      '[guidance](https://github.com/badges/shields/blob/master/CONTRIBUTING.md#logos) ',
      'for logo submissions.',
    ].join('')
  )
}

if (capitals.created || underscores.created) {
  fail(
    [
      'JavaScript source files should be named with `kebab-case` ',
      '(dash-separated lowercase).',
    ].join('')
  )
}

const allFiles = danger.git.created_files.concat(danger.git.modified_files)

allFiles.forEach(file => {
  // eslint-disable-next-line promise/prefer-await-to-then
  danger.git.diffForFile(file).then(diff => {
    if (/\+.*assert[(.]/.test(diff.diff)) {
      warn(
        [
          `Found 'assert' statement added in \`${file}\`. <br>`,
          'Please ensure tests are written using Chai ',
          '[expect syntax](http://chaijs.com/guide/styles/#expect)',
        ].join('')
      )
    }
  })
})

function onlyUnique(value, index, self) {
  return self.indexOf(value) === index
}

const affectedServices = allFiles
  .map(file => {
    const match = file.match(/^services\/(.+)\/.+\.service.js$/)
    return match ? match[1] : undefined
  })
  .filter(Boolean)
  .filter(onlyUnique)

const testedServices = allFiles
  .map(file => {
    const match = file.match(/^services\/(.+)\/.+\.tester.js$/)
    return match ? match[1] : undefined
  })
  .filter(Boolean)
  .filter(onlyUnique)

affectedServices.forEach(service => {
  if (testedServices.indexOf(service) === -1) {
    warn(
      [
        `This PR modified service code for <kbd>${service}</kbd> but not its test code. <br>`,
        "That's okay so long as it's refactoring existing code.",
      ].join('')
    )
  }
})

// Prevent merging exclusive services tests.
noTestShortcuts({
  testFilePredicate: filePath => filePath.endsWith('.tester.js'),
  patterns: {
    only: ['only()'],
  },
})