"use client";

import React, { useState, useEffect } from 'react';
import { usePathname, useRouter } from 'next/navigation';
import Link from 'next/link';
import { motion, AnimatePresence } from 'framer-motion';
import {
  LayoutDashboard, BookOpen, FileQuestion, Users, Settings, LogOut,
  Bell, Search, GraduationCap, ScrollText, ClipboardList, Database,
  Menu, X, CalendarDays, Terminal
} from 'lucide-react';
import { useAuth } from '@/lib/auth-context';
import { getApiMode, setApiMode } from '@/services/api';

const NavItem = ({ icon: Icon, label, href, isActive }: any) => (
  <Link href={href} className="block w-full">
    <div className={`
        w-full flex items-center gap-3 px-4 py-3 rounded-2xl transition-all duration-300 group relative overflow-hidden
        ${isActive
        ? 'text-white shadow-lg shadow-blue-500/30'
        : 'text-gray-500 hover:bg-gray-100 hover:text-gray-900'
      }
      `}>
      {isActive && (
        // Fix: cast props to any to avoid framer-motion type errors
        <motion.div
          {...({
            layoutId: "activeNav",
            initial: false,
            transition: { type: "spring", stiffness: 400, damping: 30 }
          } as any)}
          className="absolute inset-0 bg-blue-600 z-0"
        />
      )}
      <div className="relative z-10 flex items-center gap-3">
        <Icon size={20} strokeWidth={isActive ? 2.5 : 2} />
        <span className="text-[15px] font-medium tracking-tight">{label}</span>
      </div>
    </div>
  </Link>
);

export const Sidebar = () => {
  const { user, logout } = useAuth();
  const pathname = usePathname() || '';
  const router = useRouter();
  const [isMock, setIsMock] = useState(getApiMode());
  const [isMobileMenuOpen, setIsMobileMenuOpen] = useState(false);

  const renderNavItems = () => {
    if (user?.role === 'Student') {
      return (
        <>
          <NavItem icon={LayoutDashboard} label="我的概览" href="/dashboard" isActive={pathname === '/dashboard'} />
          <NavItem icon={ClipboardList} label="我的作业" href="/assignments" isActive={pathname.startsWith('/assignments')} />
          <NavItem icon={Users} label="我的班级" href="/classes" isActive={pathname.startsWith('/classes')} />
          <NavItem icon={CalendarDays} label="我的课表" href="/schedule" isActive={pathname === '/schedule'} />
        </>
      )
    }
    return (
      <>
        <NavItem icon={LayoutDashboard} label="教学概览" href="/dashboard" isActive={pathname === '/dashboard'} />
        <NavItem icon={BookOpen} label="课程标准" href="/curriculum" isActive={pathname === '/curriculum'} />
        <NavItem icon={ScrollText} label="考试引擎" href="/exams" isActive={pathname.startsWith('/exams')} />
        <NavItem icon={ClipboardList} label="作业发布" href="/assignments" isActive={pathname.startsWith('/assignments')} />
        <NavItem icon={FileQuestion} label="题库资源" href="/questions" isActive={pathname === '/questions'} />
        <NavItem icon={CalendarDays} label="课表管理" href="/schedule" isActive={pathname === '/schedule'} />
        <NavItem icon={Users} label="班级管理" href="/classes" isActive={pathname.startsWith('/classes')} />
      </>
    )
  };

  const SidebarContent = () => (
    <div className="h-full flex flex-col">
      <div className="flex items-center gap-4 px-2 py-6 mb-2">
        <div className="w-10 h-10 rounded-xl bg-gradient-to-br from-blue-500 to-indigo-600 flex items-center justify-center text-white font-bold shadow-lg shadow-blue-500/30">
          <GraduationCap size={20} />
        </div>
        <div>
          <span className="font-bold text-xl tracking-tight block leading-none">EduNexus</span>
          <span className="text-xs text-gray-400 font-medium tracking-wide">专业版</span>
        </div>
      </div>

      <nav className="flex-1 space-y-2">
        {renderNavItems()}
      </nav>

      <div className="pt-6 border-t border-gray-100 space-y-2">
        <button
          onClick={() => { setApiMode(!isMock); setIsMock(!isMock); }}
          className={`w-full flex items-center gap-3 px-4 py-2.5 rounded-xl transition-colors text-xs font-bold uppercase tracking-wider border ${isMock ? 'bg-amber-50 text-amber-600 border-amber-200' : 'bg-green-50 text-green-600 border-green-200'}`}
        >
          <Database size={14} />
          {isMock ? 'Mock Data' : 'Real API'}
        </button>

        <NavItem icon={Terminal} label="控制台配置" href="/consoleconfig" isActive={pathname === '/consoleconfig'} />
        <NavItem icon={Settings} label="系统设置" href="/settings" isActive={pathname === '/settings'} />

        <button
          onClick={logout}
          className="w-full flex items-center gap-3 px-4 py-3 rounded-2xl text-red-500 hover:bg-red-50 transition-colors group"
        >
          <LogOut size={20} className="group-hover:-translate-x-1 transition-transform" />
          <span className="text-[15px] font-medium">退出登录</span>
        </button>
      </div>
    </div>
  );

  return (
    <>
      {/* Desktop Sidebar */}
      <aside className="fixed w-72 h-screen pl-6 py-6 hidden lg:block z-50">
        <div className="h-full bg-white/80 backdrop-blur-xl rounded-[32px] border border-white/50 shadow-[0_20px_40px_rgba(0,0,0,0.04)] flex flex-col p-6">
          <SidebarContent />
        </div>
      </aside>

      {/* Mobile Toggle */}
      <div className="lg:hidden fixed top-4 left-4 z-50">
        <button onClick={() => setIsMobileMenuOpen(true)} className="p-2 bg-white rounded-xl shadow-sm">
          <Menu size={24} />
        </button>
      </div>

      {/* Mobile Menu Overlay */}
      <AnimatePresence>
        {isMobileMenuOpen && (
          <>
            <motion.div
              initial={{ opacity: 0 }} animate={{ opacity: 1 }} exit={{ opacity: 0 }}
              className="fixed inset-0 bg-black/20 backdrop-blur-sm z-50 lg:hidden"
              onClick={() => setIsMobileMenuOpen(false)}
            />
            {/* Fix: cast props to any to avoid framer-motion type errors */}
            <motion.div
              {...({
                initial: { x: '-100%' },
                animate: { x: 0 },
                exit: { x: '-100%' },
                transition: { type: 'spring', stiffness: 300, damping: 30 }
              } as any)}
              className="fixed inset-y-0 left-0 w-72 bg-white z-50 p-6 flex flex-col shadow-2xl lg:hidden"
            >
              <div className="absolute top-4 right-4">
                <button onClick={() => setIsMobileMenuOpen(false)} className="p-2 hover:bg-gray-100 rounded-full">
                  <X size={20} className="text-gray-500" />
                </button>
              </div>
              <SidebarContent />
            </motion.div>
          </>
        )}
      </AnimatePresence>
    </>
  );
};