thumbhash-gen/src/utils.ts

Generate ThumbHash for your images

import { red, green, italic } from 'ansis'
import fs from 'fs'
import { createRequire } from 'module'
import path from 'path'
import { fileURLToPath } from 'url'
import { InvalidArgumentError } from 'commander'

export const AVAILABLE_FORMATS = ['base64', 'url_data', 'png']

export const parseFormatArg = (arg: string) => {
  if (AVAILABLE_FORMATS.includes(arg)) {
    return arg
  }

  const errorMessage = `Allowed choices are ${AVAILABLE_FORMATS.join(', ')}`
  throw new InvalidArgumentError(errorMessage)
}

const packagePath = () => {
  const require = createRequire(import.meta.url)
  const paths = require.resolve
    .paths('thumbhash-gen')
    ?.filter((p) => p.includes(path.join('thumbhash-gen', 'node_modules')))

  if (paths?.[0]) {
    return path.join(paths?.[0] as string, '..')
  }

  const distPath = path.dirname(fileURLToPath(import.meta.url))
  return path.join(distPath, '..')
}

export const version = () => {
  const uri = path.join(packagePath(), 'package.json')
  const file = fs.readFileSync(uri, 'utf8')
  const pjson = JSON.parse(file)
  return pjson?.version
}

type Log = {
  message: string
  status?: 'success' | 'error'
}

export const log = ({ message, status }: Log) => {
  const statusPrefix = { error: red('✖'), success: green('✔') }
  const prefix = status ? statusPrefix[status] : ''
  console.log(` ${prefix} ${message}`)
}

export const fileExists = (filename: string) => {
  const exists = fs.existsSync(filename)

  if (!exists) {
    const message = `File "${filename}" not found!`
    log({ message, status: 'error' })
  }

  return exists
}

export const STATUS = {
  success: 0,
  fileNotFound: 1,
  readFileError: 2,
  imageFetchError: 3,
  unknownFormat: 4,
  pngCreateError: 5,
  emptyHash: 6,
}

/* Try catch
 * Discussion: https://gist.github.com/t3dotgg/a486c4ae66d32bf17c09c73609dacc5b
 */

type Success<T> = {
  data: T
  error?: never
}

type Failure<E> = {
  data?: never
  error: E
}

type Result<T, E = Error> = Success<T> | Failure<E>

export async function tryCatch<T, E = Error>(
  promise: Promise<T>,
): Promise<Result<T, E>> {
  try {
    const data = await promise
    return { data }
  } catch (error) {
    return { error: error as E }
  }
}

export const addDateToName = (name: string) => {
  const now = new Date()
  const year = now.getFullYear()
  const month = String(now.getMonth() + 1).padStart(2, '0')
  const day = now.getDate().toString().padStart(2, '0')
  const hour = now.getHours().toString().padStart(2, '0')
  const minute = now.getMinutes().toString().padStart(2, '0')
  const second = now.getSeconds().toString().padStart(2, '0')

  return `${name}.${year}-${month}-${day}_${hour}-${minute}-${second}`
}

type UniqueFilename = {
  filename: string
  ext: string
  dir?: string
}

export const uniqueFilename = ({ filename, ext, dir }: UniqueFilename) => {
  const parts = filename.split('.')
  if (parts.length > 1) {
    parts.pop()
  }

  const name = addDateToName(parts.join('.'))
  const fullname = `${name}.${ext}`
  return dir ? path.join(dir, fullname) : fullname
}

export const filenameFromUrl = (url: string): string => {
  const _url = url.endsWith('/') ? url.slice(0, url.length - 1) : url
  const name = _url.split('/').pop() ?? 'file_from_url'
  return name
}