import type { App } from 'vuepress'
import type { Page } from 'vuepress/core'
import type { EncryptOptions, ThemePageData } from '../../shared/index.js'
import type { FsCache } from '../utils/index.js'
import { isEmptyObject, isNumber, isString, toArray } from '@pengzhanbo/utils'
import { encodeData, removeLeadingSlash } from '@vuepress/helper'
import { getThemeConfig } from '../loadConfig/index.js'
import { createFsCache, genEncrypt, hash, perf, resolveContent, writeTemp } from '../utils/index.js'

export type EncryptConfig = readonly [
  boolean, // global
  string, // separator
  string, // admin
  string[], // keys
  Record<string, string>, // rules
]

const isStringLike = (value: unknown): boolean => isString(value) || isNumber(value)

const separator = ':'
let contentHash = ''
let fsCache: FsCache<[string, EncryptConfig]> | null = null

export async function prepareEncrypt(app: App): Promise<void> {
  perf.mark('prepare:encrypt')
  const { encrypt } = getThemeConfig()
  if (!fsCache && app.env.isDev) {
    fsCache = createFsCache(app, 'encrypt')
    await fsCache.read()
  }
  contentHash = fsCache?.data?.[0] ?? ''
  let resolvedEncrypt = fsCache?.data?.[1]
  const currentHash = encrypt ? hash(JSON.stringify(encrypt)) : ''

  if (!contentHash || contentHash !== currentHash || !resolvedEncrypt) {
    contentHash = currentHash
    resolvedEncrypt = resolveEncrypt(encrypt)
  }
  await writeTemp(app, 'internal/encrypt.js', resolveContent(app, {
    name: 'encrypt',
    content: resolvedEncrypt,
  }))

  fsCache?.write([currentHash, resolvedEncrypt])

  perf.log('prepare:encrypt')
}

function resolveEncrypt(encrypt?: EncryptOptions): EncryptConfig {
  const admin = encrypt?.admin
    ? toArray(encrypt.admin)
        .filter(isStringLike)
        .map(item => genEncrypt(item))
        .join(separator)
    : ''

  const encryptRules = Object.keys(encrypt?.rules ?? {}).reduce((acc, key) => {
    acc[encodeData(key)] = encrypt!.rules![key]
    return acc
  }, {} as Record<string, string | string[]>)

  const rules: Record<string, string> = {}
  const keys = Object.keys(encryptRules)

  if (!isEmptyObject(encryptRules)) {
    Object.keys(encryptRules).forEach((key) => {
      const index = keys.indexOf(key)

      rules[String(index)] = toArray(encryptRules[key])
        .filter(isStringLike)
        .map(item => genEncrypt(item))
        .join(separator)
    })
  }

  return [encrypt?.global ?? false, separator, admin, keys, rules]
}

export function isEncryptPage(page: Page<ThemePageData>, encrypt?: EncryptOptions): boolean {
  if (!encrypt)
    return false

  if (page.data._e)
    return true

  const rules = encrypt.rules ?? {}

  return Object.keys(rules).some((match) => {
    const relativePath = page.data.filePathRelative || ''
    if (match[0] === '^') {
      const regex = new RegExp(match)
      return regex.test(page.path) || regex.test(relativePath)
    }
    if (match.endsWith('.md'))
      return relativePath.endsWith(match)

    return page.path.startsWith(match) || relativePath.startsWith(removeLeadingSlash(match))
  })
}