/* eslint-disable no-console */
const fs = require('fs')
const path = require('path')

const projectRoot = process.cwd()
const args = process.argv.slice(2)

const getArg = (name, defaultValue = '') => {
  const full = `--${name}`
  const hit = args.find((item) => item.startsWith(`${full}=`))
  if (hit) return hit.slice(full.length + 1)
  const idx = args.indexOf(full)
  if (idx !== -1 && args[idx + 1]) return args[idx + 1]
  return defaultValue
}

const hasFlag = (flag) => args.includes(`--${flag}`)

const targetDirArg = getArg('dir', 'src/views/homePage')
const replaceMode = hasFlag('replace')

const targetDir = path.resolve(projectRoot, targetDirArg)
const zhAutoPath = path.resolve(projectRoot, 'src/i18n/lang/zh-CN.auto.json')
const enAutoPath = path.resolve(projectRoot, 'src/i18n/lang/en-US.auto.json')

const chinesePattern = /[\u4e00-\u9fa5]/
const ignorePattern = /^(\s*|[-:,.(){}\[\]/\\]+)$/

const readJsonSafe = (filePath) => {
  if (!fs.existsSync(filePath)) return {}
  try {
    return JSON.parse(fs.readFileSync(filePath, 'utf8'))
  } catch (error) {
    console.warn(`[warn] JSON parse failed: ${filePath}`)
    return {}
  }
}

const writeJson = (filePath, value) => {
  const content = JSON.stringify(value, null, 2) + '\n'
  fs.writeFileSync(filePath, content, 'utf8')
}

const walkFiles = (dir, bucket) => {
  const entries = fs.readdirSync(dir, { withFileTypes: true })
  entries.forEach((entry) => {
    const fullPath = path.join(dir, entry.name)
    if (entry.isDirectory()) {
      if (['node_modules', '.git', 'dist'].includes(entry.name)) return
      walkFiles(fullPath, bucket)
      return
    }
    if (!/\.(vue|js)$/.test(entry.name)) return
    bucket.push(fullPath)
  })
}

const normalizeText = (text) =>
  text
    .replace(/\s+/g, ' ')
    .replace(/ /g, ' ')
    .trim()

const keyFromText = (text) => {
  let hash = 0
  for (let i = 0; i < text.length; i += 1) {
    hash = (hash * 131 + text.charCodeAt(i)) >>> 0
  }
  return `auto.k_${hash.toString(16)}`
}

const zhMessages = readJsonSafe(zhAutoPath)
const enMessages = readJsonSafe(enAutoPath)

const reverseMap = new Map()
Object.keys(zhMessages).forEach((key) => {
  reverseMap.set(zhMessages[key], key)
})

const ensureKey = (rawText) => {
  const text = normalizeText(rawText)
  if (!text || !chinesePattern.test(text) || ignorePattern.test(text)) return null

  if (reverseMap.has(text)) return reverseMap.get(text)

  let key = keyFromText(text)
  while (zhMessages[key] && zhMessages[key] !== text) {
    key = `${key}_${Math.floor(Math.random() * 10000)}`
  }

  zhMessages[key] = text
  if (!Object.prototype.hasOwnProperty.call(enMessages, key)) {
    enMessages[key] = ''
  }
  reverseMap.set(text, key)
  return key
}

const transformTemplate = (template) => {
  let replacedCount = 0

  const textNodeRegex = />([^<>{}\n]*[\u4e00-\u9fa5][^<>{}\n]*)</g
  let updated = template.replace(textNodeRegex, (full, inner) => {
    const key = ensureKey(inner)
    if (!key || !replaceMode) return full
    replacedCount += 1
    return `>{{ $t('${key}') }}<`
  })

  const attrRegex = /\s([a-zA-Z_][\w-]*)=(["'])([^"']*[\u4e00-\u9fa5][^"']*)\2/g
  updated = updated.replace(attrRegex, (full, attr, quote, value) => {
    const key = ensureKey(value)
    if (!key || !replaceMode) return full
    replacedCount += 1
    return ` :${attr}="$t('${key}')"`
  })

  return { updated, replacedCount }
}

const processVueFile = (filePath) => {
  const raw = fs.readFileSync(filePath, 'utf8')
  const templateMatch = raw.match(/<template>([\s\S]*?)<\/template>/)
  if (!templateMatch) return { changed: false, replacedCount: 0 }

  const templateBlock = templateMatch[0]
  const templateInner = templateMatch[1]

  const beforeCount = Object.keys(zhMessages).length
  const { updated, replacedCount } = transformTemplate(templateInner)
  const afterCount = Object.keys(zhMessages).length
  const extractedCount = afterCount - beforeCount

  if (!replaceMode || replacedCount === 0) {
    return { changed: false, replacedCount: 0, extractedCount }
  }

  const replacedBlock = `<template>${updated}</template>`
  const next = raw.replace(templateBlock, replacedBlock)

  if (next !== raw) {
    fs.writeFileSync(filePath, next, 'utf8')
    return { changed: true, replacedCount, extractedCount }
  }
  return { changed: false, replacedCount: 0, extractedCount }
}

const processJsLiterals = (filePath) => {
  const raw = fs.readFileSync(filePath, 'utf8')
  const stringRegex = /(['"`])([^'"`\n]*[\u4e00-\u9fa5][^'"`\n]*)\1/g
  let match = stringRegex.exec(raw)
  while (match) {
    ensureKey(match[2])
    match = stringRegex.exec(raw)
  }
}

if (!fs.existsSync(targetDir)) {
  console.error(`[error] Directory does not exist: ${targetDirArg}`)
  process.exit(1)
}

const files = []
walkFiles(targetDir, files)

let changedFiles = 0
let replacedEntries = 0
let extractedEntries = 0

files.forEach((filePath) => {
  if (filePath.endsWith('.vue')) {
    const result = processVueFile(filePath)
    if (result.changed) changedFiles += 1
    replacedEntries += result.replacedCount || 0
    extractedEntries += result.extractedCount || 0
    return
  }
  processJsLiterals(filePath)
})

writeJson(zhAutoPath, zhMessages)
writeJson(enAutoPath, enMessages)

console.log(`[i18n] target: ${targetDirArg}`)
console.log(`[i18n] files scanned: ${files.length}`)
console.log(`[i18n] new keys extracted: ${extractedEntries}`)
console.log(`[i18n] replace mode: ${replaceMode ? 'on' : 'off'}`)
console.log(`[i18n] files changed: ${changedFiles}`)
console.log(`[i18n] nodes replaced: ${replacedEntries}`)
console.log(`[i18n] zh map: src/i18n/lang/zh-CN.auto.json`)
console.log(`[i18n] en map: src/i18n/lang/en-US.auto.json`)