import babel from '@babel/core'
import t from '@babel/types'
import { promisify } from 'node:util'
import { fileURLToPath } from 'node:url'
import globRaw from 'glob'
import { mkdir, stat, writeFile, readFile } from 'node:fs/promises'
import path from 'node:path'

const glob = promisify(globRaw)


const PACKAGE_JSON_IMPORT = /^\..*\/package.json$/
const SOURCE = 'packages/{*,@uppy/*}/src/**/*.{js,ts}?(x)'
// Files not to build (such as tests)
const IGNORE = /\.test\.jsx?$|\.test\.tsx?$|__mocks__|svelte|angular|companion\//;
// Files that should trigger a rebuild of everything on change
const META_FILES = [
  'babel.config.js',
  'package.json',
  'package-lock.json',
  'yarn.lock',
  'bin/build-lib.js',
]

function lastModified (file, createParentDir = false) {
  return stat(file).then((s) => s.mtime, async (err) => {
    if (err.code === 'ENOENT') {
      if (createParentDir) {
        await mkdir(path.dirname(file), { recursive: true })
      }
      return 0
    }
    throw err
  })
}

const versionCache = new Map()

// eslint-disable-next-line no-underscore-dangle
const __dirname = path.dirname(fileURLToPath(import.meta.url));

async function preparePackage (file) {
  const packageFolder = file.slice(0, file.indexOf('/src/'))
  if (versionCache.has(packageFolder)) return

  // eslint-disable-next-line import/no-dynamic-require, global-require
  const { version } = JSON.parse(await readFile(path.join(__dirname, '..', packageFolder, 'package.json'), 'utf8'))
  if (process.env.FRESH) {
    // in case it hasn't been done before.
    await mkdir(path.join(packageFolder, 'lib'), { recursive: true })
  }
  versionCache.set(packageFolder, version)
}

const nonJSImport = /^\.\.?\/.+\.([jt]sx|ts)$/
// eslint-disable-next-line no-shadow
function rewriteNonJSImportsToJS (path) {
  const match = nonJSImport.exec(path.node.source.value)
  if (match) {
    // eslint-disable-next-line no-param-reassign
    path.node.source.value = `${match[0].slice(0, -match[1].length)}js`
  }
}

console.log('Using Babel version:', JSON.parse(await readFile(fileURLToPath(import.meta.resolve('@babel/core/package.json')), 'utf8')).version)

const metaMtimes = await Promise.all(META_FILES.map((filename) => lastModified(path.join(__dirname, '..', filename))))
const metaMtime = Math.max(...metaMtimes)

const files = await glob(SOURCE)
/* eslint-disable no-continue */
for (const file of files) {
  if (IGNORE.test(file)) {
    continue
  }
  await preparePackage(file)
  const libFile = file.replace('/src/', '/lib/').replace(/\.[jt]sx?$/, '.js')

  // on a fresh build, rebuild everything.
  if (!process.env.FRESH) {
    const [srcMtime, libMtime] = await Promise.all([
      lastModified(file),
      lastModified(libFile, true),
    ])
    // Skip files that haven't changed
    if (srcMtime < libMtime && metaMtime < libMtime) {
      continue
    }
  }

  const plugins = [{
    visitor: {
      // eslint-disable-next-line no-shadow
      ImportDeclaration (path) {
        rewriteNonJSImportsToJS(path)
        if (PACKAGE_JSON_IMPORT.test(path.node.source.value)
            && path.node.specifiers.length === 1
            && path.node.specifiers[0].type === 'ImportDefaultSpecifier') {
          // Vendor-in version number from package.json files:
          const version = versionCache.get(file.slice(0, file.indexOf('/src/')))
          if (version != null) {
            const [{ local }] = path.node.specifiers
            path.replaceWith(
              t.variableDeclaration('const', [t.variableDeclarator(local,
                t.objectExpression([
                  t.objectProperty(t.stringLiteral('version'), t.stringLiteral(version)),
                ]))]),
            )
          }
        }
      },

      ExportAllDeclaration: rewriteNonJSImportsToJS,
      // eslint-disable-next-line no-shadow
      ExportNamedDeclaration (path) {
        if (path.node.source != null) {
          rewriteNonJSImportsToJS(path)
        }
      },
    },
  }]
  const isTSX = file.endsWith('.tsx')
  if (isTSX || file.endsWith('.ts')) {
    plugins.push(['@babel/plugin-transform-typescript', {
      disallowAmbiguousJSXLike: true,
      isTSX,
      jsxPragma: 'h',
      jsxPragmaFrag: 'Fragment',
    }])
  }

  const { code, map } = await babel.transformFileAsync(file, {
    sourceMaps: true,
    plugins,
    // no comments because https://github.com/transloadit/uppy/pull/4868#issuecomment-1897717779
    comments: !process.env.DIFF_BUILDER,
  })
  const [{ default: chalk }] = await Promise.all([
    import('chalk'),
    writeFile(libFile, code),
    writeFile(`${libFile}.map`, JSON.stringify(map)),
  ])
  console.log(chalk.green('Compiled lib:'), chalk.magenta(libFile))
}
/* eslint-enable no-continue */