import type { RouteLocationNormalized, Router } from 'vue-router'

/**
 * 导航防护类，用于防止快速路由切换导致的问题
 */
export class NavigationGuard {
  private router: Router
  private isNavigating = false
  private pendingNavigation: string | null = null
  private navigationTimer: NodeJS.Timeout | null = null
  private readonly NAVIGATION_DEBOUNCE = 100 // 100ms防抖
  private lastNavigationTime = 0

  constructor(router: Router) {
    this.router = router
    this.setupGuards()
  }

  private setupGuards() {
    // 在路由开始时设置导航状态
    this.router.beforeEach((to, from, next) => {
      const targetPath = to.fullPath
      const currentTime = Date.now()

      // 检查是否是页面刷新或首次加载（from.name为null或undefined）
      const isPageRefresh = !from.name || from.fullPath === '/'

      // 如果是页面刷新，直接重置状态并允许导航
      if (isPageRefresh) {
        this.resetNavigationState()
        this.lastNavigationTime = currentTime
        next()
        return
      }

      // 检查是否是快速重复点击（时间间隔小于防抖时间且目标路径相同）
      const timeSinceLastNavigation = currentTime - this.lastNavigationTime
      const isQuickDuplicate = timeSinceLastNavigation < this.NAVIGATION_DEBOUNCE
        && this.pendingNavigation === targetPath

      if (isQuickDuplicate) {
        console.warn('快速重复导航被阻止:', targetPath)
        return next(false)
      }

      // 更新导航状态
      this.isNavigating = true
      this.pendingNavigation = targetPath
      this.lastNavigationTime = currentTime

      // 清除之前的定时器
      if (this.navigationTimer) {
        clearTimeout(this.navigationTimer)
      }

      // 设置导航完成的定时器
      this.navigationTimer = setTimeout(() => {
        this.isNavigating = false
        this.pendingNavigation = null
      }, this.NAVIGATION_DEBOUNCE)

      next()
    })

    // 在路由完成或取消时重置状态
    this.router.afterEach(() => {
      this.resetNavigationState()
    })

    // 监听导航错误
    this.router.onError((error) => {
      console.error('Navigation error:', error)
      this.resetNavigationState()
    })
  }

  private resetNavigationState() {
    if (this.navigationTimer) {
      clearTimeout(this.navigationTimer)
      this.navigationTimer = null
    }
    this.isNavigating = false
    this.pendingNavigation = null
    // 注意：不重置 lastNavigationTime，保持防抖效果
  }

  /**
   * 安全的路由跳转
   */
  async safePush(to: string | RouteLocationNormalized): Promise<boolean> {
    try {
      // 如果正在导航到相同路由，则忽略
      if (this.pendingNavigation === (typeof to === 'string' ? to : to.fullPath)) {
        return true
      }

      await this.router.push(to)
      return true
    }
    catch (error: any) {
      // 忽略重复导航错误
      if (error.name === 'NavigationDuplicated') {
        return true
      }
      console.error('Navigation failed:', error)
      return false
    }
  }

  /**
   * 安全的路由替换
   */
  async safeReplace(to: string | RouteLocationNormalized): Promise<boolean> {
    try {
      await this.router.replace(to)
      return true
    }
    catch (error: any) {
      if (error.name === 'NavigationDuplicated') {
        return true
      }
      console.error('Navigation replace failed:', error)
      return false
    }
  }

  /**
   * 检查是否正在导航
   */
  isNavigatingTo(path: string): boolean {
    return this.isNavigating && this.pendingNavigation === path
  }

  /**
   * 清理资源
   */
  destroy() {
    this.resetNavigationState()
  }
}

/**
 * 创建导航防护实例
 */
export function createNavigationGuard(router: Router): NavigationGuard {
  return new NavigationGuard(router)
}