import { Plugin } from 'vite'
import fs from 'fs'
import path from 'path'

interface FileWatcherOptions {
  file: string;
  fn: (content: string) => void;
  delay?: number;
}

export function fileWatcher(options: FileWatcherOptions): Plugin {
  const {file, fn, delay = 300} = options
  let debounceTimer: NodeJS.Timeout | null = null

  return {
    name: 'file-watcher-plugin',
    configureServer(server) {
      server.watcher.add(path.resolve(file))

      server.watcher.on('change', (filePath: string) => {
        if (filePath === path.resolve(file)) {
          if (debounceTimer) clearTimeout(debounceTimer)
          debounceTimer = setTimeout(() => {
            try {
              const content = fs.readFileSync(filePath, 'utf-8')
              fn(content)
            } catch (error) {
              console.error('文件变化处理失败:', error)
            }
          }, delay)
        }
      })
    },
  }
}