import fs from 'node:fs'
import path from 'node:path'

const cwd = process.cwd()
const templateDir = path.join(cwd, 'templates', 'react-vite-glitch-component')

function fail(message) {
  console.error(message)
  process.exit(1)
}

function toKebabCase(value) {
  return value
    .trim()
    .replace(/([a-z0-9])([A-Z])/g, '$1-$2')
    .replace(/[^a-zA-Z0-9]+/g, '-')
    .replace(/^-+|-+$/g, '')
    .toLowerCase()
}

function toSnakeCase(value) {
  return value.replace(/-/g, '_')
}

function toPascalCase(value) {
  return value
    .split('-')
    .filter(Boolean)
    .map((segment) => segment.charAt(0).toUpperCase() + segment.slice(1))
    .join('')
}

function toTitleCase(value) {
  return value
    .split('-')
    .filter(Boolean)
    .map((segment) => segment.charAt(0).toUpperCase() + segment.slice(1))
    .join(' ')
}

function parseArgs(argv) {
  const args = [...argv]
  const result = {
    componentId: '',
    title: '',
    dir: ''
  }

  while (args.length > 0) {
    const arg = args.shift()
    if (!arg) continue

    if (!result.componentId && !arg.startsWith('--')) {
      result.componentId = arg
      continue
    }

    if (arg === '--title') {
      result.title = args.shift() ?? ''
      continue
    }

    if (arg === '--dir') {
      result.dir = args.shift() ?? ''
      continue
    }

    fail(`Unknown argument: ${arg}`)
  }

  return result
}

function copyTemplate(sourceDir, destinationDir, replacements) {
  fs.mkdirSync(destinationDir, { recursive: true })

  for (const entry of fs.readdirSync(sourceDir, { withFileTypes: true })) {
    const sourcePath = path.join(sourceDir, entry.name)
    const destinationPath = path.join(destinationDir, entry.name)

    if (entry.isDirectory()) {
      copyTemplate(sourcePath, destinationPath, replacements)
      continue
    }

    const source = fs.readFileSync(sourcePath, 'utf8')
    const rendered = Object.entries(replacements).reduce(
      (content, [key, value]) => content.replaceAll(key, value),
      source
    )
    fs.writeFileSync(destinationPath, rendered)
  }
}

const options = parseArgs(process.argv.slice(2))
if (!options.componentId) {
  fail('Usage: npm run glitch:new -- <component-id> --title "Display Name" [--dir /custom/path]')
}

if (!fs.existsSync(templateDir)) {
  fail(`Template directory not found: ${templateDir}`)
}

const componentId = toKebabCase(options.componentId)
if (!componentId) {
  fail('Component id resolved to an empty value.')
}

const folderName = `glitch_${toSnakeCase(componentId)}`
const displayName = options.title.trim() || toTitleCase(componentId)
const bundleName = componentId
const destinationDir = options.dir
  ? path.resolve(cwd, options.dir)
  : path.join(cwd, folderName)

if (fs.existsSync(destinationDir)) {
  fail(`Destination already exists: ${destinationDir}`)
}

copyTemplate(templateDir, destinationDir, {
  '__COMPONENT_ID__': componentId,
  '__COMPONENT_DISPLAY_NAME__': displayName,
  '__LIB_GLOBAL_NAME__': toPascalCase(componentId),
  '__FOLDER_NAME__': folderName,
  '__BUNDLE_NAME__': bundleName
})

console.log(`Created ${folderName}`)
console.log(`Path: ${destinationDir}`)
console.log('Next steps:')
console.log(`  cd ${folderName}`)
console.log('  npm install')
console.log('  npm run dev')