'use client'

import { useState, type ReactNode } from 'react'
import Link from 'next/link'
import { usePathname, useRouter } from 'next/navigation'
import {
  LayoutDashboard,
  Users,
  Server,
  Cpu,
  Key,
  BarChart3,
  ArrowLeftRight,
  Settings,
  FileText,
  MessageSquare,
  Bot,
  LogOut,
  ChevronLeft,
  Menu,
  Bell,
} from 'lucide-react'
import { AuthGuard, useAuth } from '@/components/auth-guard'
import { logout } from '@/lib/auth'
import { cn } from '@/lib/utils'

/** 权限常量 — 与后端 db.rs SEED_ROLES 保持同步 */
const ROLE_PERMISSIONS: Record<string, string[]> = {
  super_admin: ['admin:full', 'account:admin', 'provider:manage', 'model:manage', 'relay:admin', 'config:write', 'prompt:read', 'prompt:write', 'prompt:publish', 'prompt:admin'],
  admin: ['account:read', 'account:admin', 'provider:manage', 'model:read', 'model:manage', 'relay:use', 'relay:admin', 'config:read', 'config:write', 'prompt:read', 'prompt:write', 'prompt:publish'],
  user: ['model:read', 'relay:use', 'config:read', 'prompt:read'],
}

/** 根据 role 获取权限列表 */
function getPermissionsForRole(role: string): string[] {
  return ROLE_PERMISSIONS[role] ?? []
}

const navItems = [
  { href: '/', label: '仪表盘', icon: LayoutDashboard },
  { href: '/accounts', label: '账号管理', icon: Users, permission: 'account:admin' },
  { href: '/providers', label: '服务商', icon: Server, permission: 'provider:manage' },
  { href: '/models', label: '模型管理', icon: Cpu, permission: 'model:read' },
  { href: '/agent-templates', label: 'Agent 模板', icon: Bot, permission: 'model:read' },
  { href: '/api-keys', label: 'API 密钥', icon: Key, permission: 'admin:full' },
  { href: '/usage', label: '用量统计', icon: BarChart3, permission: 'admin:full' },
  { href: '/relay', label: '中转任务', icon: ArrowLeftRight, permission: 'relay:use' },
  { href: '/config', label: '系统配置', icon: Settings, permission: 'config:read' },
  { href: '/prompts', label: '提示词管理', icon: MessageSquare, permission: 'prompt:read' },
  { href: '/logs', label: '操作日志', icon: FileText, permission: 'admin:full' },
]

function Sidebar({
  collapsed,
  onToggle,
}: {
  collapsed: boolean
  onToggle: () => void
}) {
  const pathname = usePathname()
  const router = useRouter()
  const { account } = useAuth()

  const permissions = account ? getPermissionsForRole(account.role) : []

  function handleLogout() {
    logout()
    router.replace('/login')
  }

  const filteredNavItems = navItems.filter((item) => {
    if (!item.permission) return true
    return permissions.includes(item.permission) || permissions.includes('admin:full')
  })

  return (
    <aside
      className={cn(
        'fixed left-0 top-0 z-40 flex h-screen flex-col border-r border-border bg-card transition-all duration-300',
        collapsed ? 'w-16' : 'w-64',
      )}
    >
      {/* Logo */}
      <div className="flex h-14 items-center border-b border-border px-4">
        <Link href="/" className="flex items-center gap-2 cursor-pointer">
          <div className="flex h-8 w-8 items-center justify-center rounded-md bg-primary text-primary-foreground font-bold text-sm">
            Z
          </div>
          {!collapsed && (
            <div className="flex flex-col">
              <span className="text-sm font-bold text-foreground">ZCLAW</span>
              <span className="text-[10px] text-muted-foreground">Admin</span>
            </div>
          )}
        </Link>
      </div>

      {/* 导航 */}
      <nav className="flex-1 overflow-y-auto scrollbar-thin py-2 px-2">
        <ul className="space-y-1">
          {filteredNavItems.map((item) => {
            const isActive =
              item.href === '/'
                ? pathname === '/'
                : pathname.startsWith(item.href)
            const Icon = item.icon

            return (
              <li key={item.href}>
                <Link
                  href={item.href}
                  className={cn(
                    'flex items-center gap-3 rounded-md px-3 py-2 text-sm font-medium transition-colors duration-200 cursor-pointer',
                    isActive
                      ? 'bg-muted text-green-400'
                      : 'text-muted-foreground hover:bg-muted hover:text-foreground',
                    collapsed && 'justify-center px-2',
                  )}
                  title={collapsed ? item.label : undefined}
                >
                  <Icon className="h-4 w-4 shrink-0" />
                  {!collapsed && <span>{item.label}</span>}
                </Link>
              </li>
            )
          })}
        </ul>
      </nav>

      {/* 底部折叠按钮 */}
      <div className="border-t border-border p-2">
        <button
          onClick={onToggle}
          className="flex w-full items-center justify-center rounded-md px-3 py-2 text-muted-foreground hover:bg-muted hover:text-foreground transition-colors duration-200 cursor-pointer"
        >
          <ChevronLeft
            className={cn(
              'h-4 w-4 transition-transform duration-200',
              collapsed && 'rotate-180',
            )}
          />
        </button>
      </div>

      {/* 用户信息 */}
      {!collapsed && (
        <div className="border-t border-border p-3">
          <div className="flex items-center gap-3">
            <div className="flex h-8 w-8 shrink-0 items-center justify-center rounded-full bg-muted text-xs font-medium text-foreground">
              {account?.display_name?.[0] || account?.username?.[0] || 'A'}
            </div>
            <div className="flex-1 min-w-0">
              <p className="truncate text-sm font-medium text-foreground">
                {account?.display_name || account?.username || 'Admin'}
              </p>
              <p className="truncate text-xs text-muted-foreground">
                {account?.role || 'admin'}
              </p>
            </div>
            <button
              onClick={handleLogout}
              className="rounded-md p-1.5 text-muted-foreground hover:bg-muted hover:text-destructive transition-colors duration-200 cursor-pointer"
              title="退出登录"
            >
              <LogOut className="h-4 w-4" />
            </button>
          </div>
        </div>
      )}
    </aside>
  )
}

function Header() {
  const pathname = usePathname()
  const currentNav = navItems.find(
    (item) =>
      item.href === '/'
        ? pathname === '/'
        : pathname.startsWith(item.href),
  )

  return (
    <header className="sticky top-0 z-30 flex h-14 items-center border-b border-border bg-background/80 backdrop-blur-sm px-6">
      {/* 移动端菜单按钮 */}
      <MobileMenuButton />

      {/* 页面标题 */}
      <h1 className="text-lg font-semibold text-foreground">
        {currentNav?.label || '仪表盘'}
      </h1>

      <div className="ml-auto flex items-center gap-2">
        {/* 通知 */}
        <button
          className="relative rounded-md p-2 text-muted-foreground hover:bg-muted hover:text-foreground transition-colors duration-200 cursor-pointer"
          title="通知"
        >
          <Bell className="h-4 w-4" />
        </button>
      </div>
    </header>
  )
}

function MobileMenuButton() {
  // Placeholder for mobile menu toggle
  return (
    <button
      className="mr-3 rounded-md p-2 text-muted-foreground hover:bg-muted hover:text-foreground transition-colors duration-200 lg:hidden cursor-pointer"
    >
      <Menu className="h-5 w-5" />
    </button>
  )
}

export default function DashboardLayout({ children }: { children: ReactNode }) {
  const [sidebarCollapsed, setSidebarCollapsed] = useState(false)

  return (
    <AuthGuard>
      <div className="flex min-h-screen">
        <Sidebar
          collapsed={sidebarCollapsed}
          onToggle={() => setSidebarCollapsed(!sidebarCollapsed)}
        />
        <div
          className={cn(
            'flex flex-1 flex-col transition-all duration-300',
            sidebarCollapsed ? 'ml-16' : 'ml-64',
          )}
        >
          <Header />
          <main className="flex-1 overflow-auto p-6 scrollbar-thin">
            {children}
          </main>
        </div>
      </div>
    </AuthGuard>
  )
}