#!/usr/bin/env node

import { readFileSync } from 'node:fs'
import { dirname, join } from 'node:path'
import { fileURLToPath } from 'node:url'

import { customAlphabet, nanoid } from '../index.js'

function print(msg) {
  process.stdout.write(msg + '\n')
}

function error(msg) {
  process.stderr.write(msg + '\n')
  process.exit(1)
}

if (process.argv.includes('--version') || process.argv.includes('-v')) {
  let root = dirname(fileURLToPath(import.meta.url))
  let pkg = JSON.parse(readFileSync(join(root, '..', 'package.json'), 'utf8'))
  print(pkg.version)
  process.exit()
}

if (process.argv.includes('--help') || process.argv.includes('-h')) {
  print(`Usage
  $ nanoid [options]

Options
  -s, --size       Generated ID size
  -a, --alphabet   Alphabet to use
  -v, --version    Show version number
  -h, --help       Show this help

Examples
  $ nanoid -s 15
  S9sBF77U6sDB8Yg

  $ nanoid --size 10 --alphabet abc
  bcabababca`)
  process.exit()
}

let alphabet, size
for (let i = 2; i < process.argv.length; i++) {
  let arg = process.argv[i]
  if (arg === '--size' || arg === '-s') {
    size = Number(process.argv[i + 1])
    i += 1
    if (Number.isNaN(size) || size <= 0) {
      error('Size must be positive integer')
    }
  } else if (arg === '--alphabet' || arg === '-a') {
    alphabet = process.argv[i + 1]
    i += 1
  } else {
    error('Unknown argument ' + arg)
  }
}

if (alphabet) {
  let customNanoid = customAlphabet(alphabet, size)
  print(customNanoid())
} else {
  print(nanoid(size))
}