import fs from 'fs-extra'
import { createRequire } from 'node:module'

import type { Configuration } from './defineConfig'

import paths from '../config/paths'
import { resolveModule } from './resolveModule'

const require = createRequire(import.meta.url)

const defaultOverride: Configuration = {
  minify: true,
  proxy: [],
  extraPostCSSPlugins: [],
  import: [],
  pure_funcs: ['console.log'],
}

function migrateOverride(override: Configuration) {
  // 迁移提示 v1 -> v2，后续版本会删除这些废弃的配置项
  if ('transformNodeModules' in override) {
    console.warn('transformNodeModules 配置已废弃，请删除这个配置项')
  }

  if ('minifyImage' in override) {
    console.warn('minifyImage 配置已废弃，请删除这个配置项')
  }

  if (typeof override.minify !== 'boolean') {
    console.warn('minify 类型错误，请使用boolean类型，已自动设置为 true')
    override.minify = true
  }

  if ('babel' in override) {
    throw new Error(
      'babel 配置已废弃，请删除这个配置项。如果有 babel-plugin-import 相关的配置，请直接使用 import 选项'
    )
  }
}

let override: Configuration | null = null

export default function getOverride(): Configuration {
  if (override) return override

  override = Object.assign({}, defaultOverride)

  if (fs.existsSync(paths.override)) {
    const userOverride = resolveModule(require(paths.override))
    if (typeof userOverride !== 'object')
      throw new Error('格式错误，请使用 npx edu g override 生成文件')
    Object.assign(override, userOverride)

    migrateOverride(override)
  }

  return override
}